Master Class

mikeross@ucla.edu

Electronic fetal monitoring lies at the crux of our efforts to assess fetal well-being and detect intrapartum fetal compromise. Yet making the most of this tool—using it meaningfully to quantify or assess fetal well-being by the heart rate tracing—has been and remains a struggle.

To understand the challenges, one only has to look at the number of groups and individuals who have proposed—and continue to propose—various systems, definitions, and recommendations for assessing fetal heart rate tracings. Finding the best assessment strategies remains a key goal in obstetrics as we work toward realizing the full potential benefits of electronic fetal monitoring.

The report issued last year by a panel convened by the National Institute of Child Health and Human Development, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine took us a step forward by initiating a consistent nomenclature of normal, abnormal, and indeterminate fetal well-being. This three-tiered system for fetal heart rate interpretation is limited, however, in that it assesses the fetal heart rate only during a discrete window of time, and provides no discrimination as to the degree of “normal.”

We need to think more broadly as we assess fetal heart rate tracings to understand where a fetus is on the spectrum of acidosis. The overall change in fetal metabolic acidosis during labor is what best reflects the risk of hypoxemia-induced organ injury. Although it's not a perfect criterion for predicting fetal well-being, the estimated degree of fetal metabolic acidosis is a much more meaningful predictor than is an estimate of the acute oxygenation status.

When seeing any normal fetal heart rate tracing at a snapshot in time, for instance, we could be dealing with a perfectly normal fetus (that is, one with a low level of acidosis) on the one hand, or we could have a fetus that is precariously close to entering severe acidosis. An abnormal fetal heart rate tracing, similarly, is not in-and-of-itself predictive of fetal metabolic acidosis.

Knowing whether a fetus has only mild acidosis, or severe acidosis, has important implications. A fetus struck with bradycardia, for instance, will tolerate the complication much better if it has mild or no significant acidosis at the start than if it is on the precipice of shifting into severe acidosis. Knowledge of the degree of acidosis equips us to better predict and manage fetal compromise and avoid unnecessary operative deliveries.

Indeed, more research is needed to better understand the change in the level of fetal metabolic acidosis with both the progression of labor and with induced fetal heart rate changes. Yet even as we work to advance our knowledge, we have learned enough about fetal acidosis to be able to seek answers to several questions: Is what's happening to the heart rate affected by hypoxia? Does the tracing reflect the degree of acidosis? Where are we on the spectrum of acidosis?

Changes in Base Deficit

The values termed “base excess” or “base deficit” are used to quantify the magnitude of metabolic acidosis during normal stages of labor. A large positive base deficit—or a large negative base excess—indicates that the body's base buffers have been used up to buffer acids and that metabolic acidosis is present.

A base deficit of 12 mmol/L—or alternatively a base excess of −12 mmol/L—is widely accepted as the threshold for risk of acute brain injury. When we're looking at a tracing, our monitoring and management plans will differ significantly, therefore, for a fetus with a normal tracing and a base deficit of 2 mmol/L compared with a fetus who has a normal tracing and a base deficit of 8 mmol/L.

The average fetus enters labor slightly acidotic with a base deficit of approximately 2 mmol/L. During the latent phase of labor, which typically represents minimal stress, the fetus incurs no real change in base deficit. During the active phase, however, the stress of the labor causes the base deficit to increase by approximately 1 mmol/L every 3-6 hours, and during the second stage, the base deficit increases by approximately 1 mmol/L every hour. This means that by the end of the first stage of labor, the fetus has a base deficit of 4 mmol/L, on average. At the end of the second stage, the average baby is born with a base deficit of approximately 5 mmol/L.

The development of mild acidosis through the stages of normal labor is analogous to an adult walking, jogging, and then sprinting. Most of us would progressively use more oxygen than we can provide as we pick up the pace, spurring a conversion from aerobic to anaerobic metabolism that results in the production of lactic acid and consequent soreness—even aching pain—in our legs. For the fetus, the latent phase of labor is the equivalent of our walking, the active phase represents jogging, and the second stage is equivalent to a sprint.

During labor, lactic acid accumulation can lead to metabolic acidosis and a blunting of the vagal regulation of the fetal heart rate and consequent loss of accelerations, loss of variability between contractions, and other changes with possible long-term sequelae.

In monitoring labor, we want to know where we are on the spectrum of acidosis. Have we gone through the active phase, for example? Where are we in the second stage? Understanding where the fetus is on this spectrum prepares us to manage any changes—any additional acidosis related to fetal heart rate decelerations—that are superimposed on the background stress of the labor process.

Acidosis and Heart Rate Patterns

Research has confirmed not only degrees of hypoxemia and fetal base deficit values during the normal course of labor; it also has provided a window of knowledge into the changes in fetal acidosis in relation to particular fetal heart rate patterns.

Early decelerations are generally well tolerated by the fetus and probably do not result in any additional acidosis. These are believed to result from fetal head compression and a subsequent hormonal or vagal response.

Similarly, mild or moderate variable fetal heart rate decelerations, which are due to modest cord compression, are well tolerated if they occur at a reasonable frequency (such as every 3 minutes). The frequency of variable decelerations is critical as lactic acid generated during the variable deceleration may be cleared across the placenta during the periods between decelerations.

When variable heart rate decelerations are severe and of increasing frequency, however, the fetus can accumulate lactic acid—sometimes rapidly—depending on the frequency. A severe variable deceleration results from complete or near-complete umbilical cord occlusion and is typically defined as one that lasts for at least 60 seconds, during which the heart rate drops below 70 beats per minute

In a study we published this year with colleagues in Canada, we found that severe variable decelerations result in an increase in base deficit of 0.5 mmol/L per minute of cord occlusion. We also found, however, that metabolic acidosis is cleared at a rate of 0.1 mmol/L per minute of recovery, when fetal heart rate is normal and stress is reduced (Am. J. Obstet. Gynecol. 2009;200:200.e1-7).

Given these rates of acid accumulation and normalization, one can understand how acidosis may develop when repetitive, severe variable decelerations occur every 3 minutes, for instance. Past a certain frequency and severity, there simply isn't enough recovery time to allow the fetus to sufficiently correct the base deficit.

Although most of us will not actually be using these acid accumulation and recovery rates to calculate specific base deficits, an awareness of the principles can aid us in assessing fetal acidosis. The concept of recovery time is an important one. Again, knowing where your patient is on the spectrum of acidosis tells you how much “buffer time” you have if something goes wrong.

There is policy, sometimes attributed to midwives, that advocates letting the patient push only during every other contraction. Given what we've learned about the development of acidosis, when pushing is associated with severe variable decelerations, there may be an advantage to pushing every other contraction in order to permit sufficient recovery time and clearance of acid between the decelerations.

One of the signals that acidosis is progressing to a moderate level (approximately 8 mmol/L) is the change in severe variable decelerations from typical (having shoulders, a sharp drop, and a sharp rise) to atypical (a loss of shoulders, a U-shaped variable deceleration, or a slow return to baseline).

Another sign of moderate acidosis is a loss of variability between contractions. These heart rate patterns need more research, but in my experience a prolonged loss of variability between contractions (unrelated to the fetal sleep state) typically does not occur until the base deficit approaches 8 mmol/L or greater. Given that the risk of brain injury begins with a base deficit of 12 mmol/L, an observation of this change provides a buffer zone during which the patient can be even more closely monitored.

It used to be thought that late decelerations were extremely worrisome, but we have learned that these patterns are usually less threatening to the fetus's accumulation of metabolic acidosis than are severe variable decelerations.

When there is good baseline variability between the decelerations, the late deceleration often reflects a vagal-mediated response and probably involves no change in the level of acidosis. When there is a loss of variability between contractions, however, the late deceleration may reflect a hypoxia-induced response. Still, the rate of acidosis accumulation is typically less than it is with severe variable decelerations.

In general, the amount of acid accumulation with late decelerations is dependent on the frequency and severity of the decelerations; the accumulation of acidosis may range from a base deficit increase of 1 mmol/L every 5 minutes to an increase of just 1 mmol/L every 15 minutes.

One of the weak links in our understanding of fetal acidosis today is our inability to recognize preexisting acidosis or preexisting injury. We have little experience in identifying fetal heart rate patterns associated with preexisting hypoxic injuries.

Adding to the challenge is the knowledge that a post-term fetus or one with intrauterine growth restriction may begin labor with a slightly greater level of acidosis. Furthermore, fetuses with true sepsis or severe anemia may accumulate acid at an increased rate compared with normal fetuses.

Where We Stand

Practically, attempting to avoid injury by recognizing mild, moderate, and potentially severe levels of fetal acidosis means that one must carefully examine fetal heart rate tracings, not only for the time we are present in the room, but at least back to the time of our previous assessment. As much as is possible, we should understand what the entirety of the monitoring has shown.

We should attempt to factor in the known changes in fetal acidosis associated with normal stages of labor together with estimated changes in acidosis related to superimposed fetal heart rate decelerations. With an understanding of the progress and stage of labor, the current fetal heart rate pattern, and the approximate level of fetal metabolic acidosis, we will be best prepared to manage the pregnancy for an optimal outcome.

ELSEVIER GLOBAL MEDICAL NEWS

ELSEVIER GLOBAL MEDICAL NEWS

Fetal Heart Rate Monitoring

Over the years, we have endeavored to assess fetal well-being by a number of electronic and nonelectronic means with varying degrees of success. Of all these methods, fetal heart rate monitoring has withstood the test of time.

Our continued use of fetal heart rate monitoring as a means of assessing the fetus's biochemical and biophysical status has contributed much to our understanding of fetal well-being, or lack thereof. More recently, efforts have been made to better correlate variations in fetal heart rate to fetal well-being.

It is well known that the fetus is the final arbiter of intrauterine stress and may respond with compensatory mechanisms that may thwart various types of stresses. In such a scenario, the fetus may not manifest a compromised state, despite potentially harmful stress conditions. On the other hand, another fetus facing similarly stressful intrauterine conditions may struggle, exhibiting fetal distress or worse.

In reality, what matters most is the response of the fetus and not the stressful condition per se. Every attempt to monitor fetal well-being has been focused, therefore, on the response of the fetus to various types of stress. Because we're unable to conduct biochemical testing on a real-time or continuous basis, fetal heart rate monitoring often has been used as a surrogate for the biochemical adaptations by the fetus to intrauterine stress conditions.

Fetal heart rate monitoring, thus, becomes a very important diagnostic tool because the decisions that physicians make and the interventions that they undertake often are based on their interpretation of the fetal heart rate tracings. Such decisions are critical to the overall outcome of the fetus.

It is in this light that we are dedicating a Master Class to the subject of fetal acidosis and fetal heart rate assessment and have invited Dr. Michael G. Ross to serve as our guest professor this month. Dr. Ross is the chair of obstetrics and gynecology at the Harbor-UCLA Medical Center in Torrance, Calif., and professor and vice chair of obstetrics and gynecology at the David Geffen School of Medicine at the University of California, Los Angeles.

Dr. Ross's exceptional article on this topic delineates the mechanisms of fetal metabolic acidosis and its effects on fetal well-being. He also offers valuable insights on how fetal heart rate tracings might be better utilized as a powerful tool for detecting and predicting where a fetus may lie along the acidosis spectrum during various stages of labor so that interventions may be implemented to prevent severe acidosis and associated injury to the fetus.

mikeross@ucla.edu

Electronic fetal monitoring lies at the crux of our efforts to assess fetal well-being and detect intrapartum fetal compromise. Yet making the most of this tool—using it meaningfully to quantify or assess fetal well-being by the heart rate tracing—has been and remains a struggle.

To understand the challenges, one only has to look at the number of groups and individuals who have proposed—and continue to propose—various systems, definitions, and recommendations for assessing fetal heart rate tracings. Finding the best assessment strategies remains a key goal in obstetrics as we work toward realizing the full potential benefits of electronic fetal monitoring.

The report issued last year by a panel convened by the National Institute of Child Health and Human Development, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine took us a step forward by initiating a consistent nomenclature of normal, abnormal, and indeterminate fetal well-being. This three-tiered system for fetal heart rate interpretation is limited, however, in that it assesses the fetal heart rate only during a discrete window of time, and provides no discrimination as to the degree of “normal.”

We need to think more broadly as we assess fetal heart rate tracings to understand where a fetus is on the spectrum of acidosis. The overall change in fetal metabolic acidosis during labor is what best reflects the risk of hypoxemia-induced organ injury. Although it's not a perfect criterion for predicting fetal well-being, the estimated degree of fetal metabolic acidosis is a much more meaningful predictor than is an estimate of the acute oxygenation status.

When seeing any normal fetal heart rate tracing at a snapshot in time, for instance, we could be dealing with a perfectly normal fetus (that is, one with a low level of acidosis) on the one hand, or we could have a fetus that is precariously close to entering severe acidosis. An abnormal fetal heart rate tracing, similarly, is not in-and-of-itself predictive of fetal metabolic acidosis.

Knowing whether a fetus has only mild acidosis, or severe acidosis, has important implications. A fetus struck with bradycardia, for instance, will tolerate the complication much better if it has mild or no significant acidosis at the start than if it is on the precipice of shifting into severe acidosis. Knowledge of the degree of acidosis equips us to better predict and manage fetal compromise and avoid unnecessary operative deliveries.

Indeed, more research is needed to better understand the change in the level of fetal metabolic acidosis with both the progression of labor and with induced fetal heart rate changes. Yet even as we work to advance our knowledge, we have learned enough about fetal acidosis to be able to seek answers to several questions: Is what's happening to the heart rate affected by hypoxia? Does the tracing reflect the degree of acidosis? Where are we on the spectrum of acidosis?

Changes in Base Deficit

The values termed “base excess” or “base deficit” are used to quantify the magnitude of metabolic acidosis during normal stages of labor. A large positive base deficit—or a large negative base excess—indicates that the body's base buffers have been used up to buffer acids and that metabolic acidosis is present.

A base deficit of 12 mmol/L—or alternatively a base excess of −12 mmol/L—is widely accepted as the threshold for risk of acute brain injury. When we're looking at a tracing, our monitoring and management plans will differ significantly, therefore, for a fetus with a normal tracing and a base deficit of 2 mmol/L compared with a fetus who has a normal tracing and a base deficit of 8 mmol/L.

The average fetus enters labor slightly acidotic with a base deficit of approximately 2 mmol/L. During the latent phase of labor, which typically represents minimal stress, the fetus incurs no real change in base deficit. During the active phase, however, the stress of the labor causes the base deficit to increase by approximately 1 mmol/L every 3-6 hours, and during the second stage, the base deficit increases by approximately 1 mmol/L every hour. This means that by the end of the first stage of labor, the fetus has a base deficit of 4 mmol/L, on average. At the end of the second stage, the average baby is born with a base deficit of approximately 5 mmol/L.

The development of mild acidosis through the stages of normal labor is analogous to an adult walking, jogging, and then sprinting. Most of us would progressively use more oxygen than we can provide as we pick up the pace, spurring a conversion from aerobic to anaerobic metabolism that results in the production of lactic acid and consequent soreness—even aching pain—in our legs. For the fetus, the latent phase of labor is the equivalent of our walking, the active phase represents jogging, and the second stage is equivalent to a sprint.

During labor, lactic acid accumulation can lead to metabolic acidosis and a blunting of the vagal regulation of the fetal heart rate and consequent loss of accelerations, loss of variability between contractions, and other changes with possible long-term sequelae.

In monitoring labor, we want to know where we are on the spectrum of acidosis. Have we gone through the active phase, for example? Where are we in the second stage? Understanding where the fetus is on this spectrum prepares us to manage any changes—any additional acidosis related to fetal heart rate decelerations—that are superimposed on the background stress of the labor process.

Acidosis and Heart Rate Patterns

Research has confirmed not only degrees of hypoxemia and fetal base deficit values during the normal course of labor; it also has provided a window of knowledge into the changes in fetal acidosis in relation to particular fetal heart rate patterns.

Early decelerations are generally well tolerated by the fetus and probably do not result in any additional acidosis. These are believed to result from fetal head compression and a subsequent hormonal or vagal response.

Similarly, mild or moderate variable fetal heart rate decelerations, which are due to modest cord compression, are well tolerated if they occur at a reasonable frequency (such as every 3 minutes). The frequency of variable decelerations is critical as lactic acid generated during the variable deceleration may be cleared across the placenta during the periods between decelerations.

When variable heart rate decelerations are severe and of increasing frequency, however, the fetus can accumulate lactic acid—sometimes rapidly—depending on the frequency. A severe variable deceleration results from complete or near-complete umbilical cord occlusion and is typically defined as one that lasts for at least 60 seconds, during which the heart rate drops below 70 beats per minute

In a study we published this year with colleagues in Canada, we found that severe variable decelerations result in an increase in base deficit of 0.5 mmol/L per minute of cord occlusion. We also found, however, that metabolic acidosis is cleared at a rate of 0.1 mmol/L per minute of recovery, when fetal heart rate is normal and stress is reduced (Am. J. Obstet. Gynecol. 2009;200:200.e1-7).

Given these rates of acid accumulation and normalization, one can understand how acidosis may develop when repetitive, severe variable decelerations occur every 3 minutes, for instance. Past a certain frequency and severity, there simply isn't enough recovery time to allow the fetus to sufficiently correct the base deficit.

Although most of us will not actually be using these acid accumulation and recovery rates to calculate specific base deficits, an awareness of the principles can aid us in assessing fetal acidosis. The concept of recovery time is an important one. Again, knowing where your patient is on the spectrum of acidosis tells you how much “buffer time” you have if something goes wrong.

There is policy, sometimes attributed to midwives, that advocates letting the patient push only during every other contraction. Given what we've learned about the development of acidosis, when pushing is associated with severe variable decelerations, there may be an advantage to pushing every other contraction in order to permit sufficient recovery time and clearance of acid between the decelerations.

One of the signals that acidosis is progressing to a moderate level (approximately 8 mmol/L) is the change in severe variable decelerations from typical (having shoulders, a sharp drop, and a sharp rise) to atypical (a loss of shoulders, a U-shaped variable deceleration, or a slow return to baseline).

Another sign of moderate acidosis is a loss of variability between contractions. These heart rate patterns need more research, but in my experience a prolonged loss of variability between contractions (unrelated to the fetal sleep state) typically does not occur until the base deficit approaches 8 mmol/L or greater. Given that the risk of brain injury begins with a base deficit of 12 mmol/L, an observation of this change provides a buffer zone during which the patient can be even more closely monitored.

It used to be thought that late decelerations were extremely worrisome, but we have learned that these patterns are usually less threatening to the fetus's accumulation of metabolic acidosis than are severe variable decelerations.

When there is good baseline variability between the decelerations, the late deceleration often reflects a vagal-mediated response and probably involves no change in the level of acidosis. When there is a loss of variability between contractions, however, the late deceleration may reflect a hypoxia-induced response. Still, the rate of acidosis accumulation is typically less than it is with severe variable decelerations.

In general, the amount of acid accumulation with late decelerations is dependent on the frequency and severity of the decelerations; the accumulation of acidosis may range from a base deficit increase of 1 mmol/L every 5 minutes to an increase of just 1 mmol/L every 15 minutes.

One of the weak links in our understanding of fetal acidosis today is our inability to recognize preexisting acidosis or preexisting injury. We have little experience in identifying fetal heart rate patterns associated with preexisting hypoxic injuries.

Adding to the challenge is the knowledge that a post-term fetus or one with intrauterine growth restriction may begin labor with a slightly greater level of acidosis. Furthermore, fetuses with true sepsis or severe anemia may accumulate acid at an increased rate compared with normal fetuses.

Where We Stand

Practically, attempting to avoid injury by recognizing mild, moderate, and potentially severe levels of fetal acidosis means that one must carefully examine fetal heart rate tracings, not only for the time we are present in the room, but at least back to the time of our previous assessment. As much as is possible, we should understand what the entirety of the monitoring has shown.

We should attempt to factor in the known changes in fetal acidosis associated with normal stages of labor together with estimated changes in acidosis related to superimposed fetal heart rate decelerations. With an understanding of the progress and stage of labor, the current fetal heart rate pattern, and the approximate level of fetal metabolic acidosis, we will be best prepared to manage the pregnancy for an optimal outcome.

ELSEVIER GLOBAL MEDICAL NEWS

ELSEVIER GLOBAL MEDICAL NEWS

Fetal Heart Rate Monitoring

Over the years, we have endeavored to assess fetal well-being by a number of electronic and nonelectronic means with varying degrees of success. Of all these methods, fetal heart rate monitoring has withstood the test of time.

Our continued use of fetal heart rate monitoring as a means of assessing the fetus's biochemical and biophysical status has contributed much to our understanding of fetal well-being, or lack thereof. More recently, efforts have been made to better correlate variations in fetal heart rate to fetal well-being.

It is well known that the fetus is the final arbiter of intrauterine stress and may respond with compensatory mechanisms that may thwart various types of stresses. In such a scenario, the fetus may not manifest a compromised state, despite potentially harmful stress conditions. On the other hand, another fetus facing similarly stressful intrauterine conditions may struggle, exhibiting fetal distress or worse.

In reality, what matters most is the response of the fetus and not the stressful condition per se. Every attempt to monitor fetal well-being has been focused, therefore, on the response of the fetus to various types of stress. Because we're unable to conduct biochemical testing on a real-time or continuous basis, fetal heart rate monitoring often has been used as a surrogate for the biochemical adaptations by the fetus to intrauterine stress conditions.

Fetal heart rate monitoring, thus, becomes a very important diagnostic tool because the decisions that physicians make and the interventions that they undertake often are based on their interpretation of the fetal heart rate tracings. Such decisions are critical to the overall outcome of the fetus.

It is in this light that we are dedicating a Master Class to the subject of fetal acidosis and fetal heart rate assessment and have invited Dr. Michael G. Ross to serve as our guest professor this month. Dr. Ross is the chair of obstetrics and gynecology at the Harbor-UCLA Medical Center in Torrance, Calif., and professor and vice chair of obstetrics and gynecology at the David Geffen School of Medicine at the University of California, Los Angeles.

Dr. Ross's exceptional article on this topic delineates the mechanisms of fetal metabolic acidosis and its effects on fetal well-being. He also offers valuable insights on how fetal heart rate tracings might be better utilized as a powerful tool for detecting and predicting where a fetus may lie along the acidosis spectrum during various stages of labor so that interventions may be implemented to prevent severe acidosis and associated injury to the fetus.

mikeross@ucla.edu

Electronic fetal monitoring lies at the crux of our efforts to assess fetal well-being and detect intrapartum fetal compromise. Yet making the most of this tool—using it meaningfully to quantify or assess fetal well-being by the heart rate tracing—has been and remains a struggle.

To understand the challenges, one only has to look at the number of groups and individuals who have proposed—and continue to propose—various systems, definitions, and recommendations for assessing fetal heart rate tracings. Finding the best assessment strategies remains a key goal in obstetrics as we work toward realizing the full potential benefits of electronic fetal monitoring.

The report issued last year by a panel convened by the National Institute of Child Health and Human Development, the American College of Obstetricians and Gynecologists, and the Society for Maternal-Fetal Medicine took us a step forward by initiating a consistent nomenclature of normal, abnormal, and indeterminate fetal well-being. This three-tiered system for fetal heart rate interpretation is limited, however, in that it assesses the fetal heart rate only during a discrete window of time, and provides no discrimination as to the degree of “normal.”

We need to think more broadly as we assess fetal heart rate tracings to understand where a fetus is on the spectrum of acidosis. The overall change in fetal metabolic acidosis during labor is what best reflects the risk of hypoxemia-induced organ injury. Although it's not a perfect criterion for predicting fetal well-being, the estimated degree of fetal metabolic acidosis is a much more meaningful predictor than is an estimate of the acute oxygenation status.

When seeing any normal fetal heart rate tracing at a snapshot in time, for instance, we could be dealing with a perfectly normal fetus (that is, one with a low level of acidosis) on the one hand, or we could have a fetus that is precariously close to entering severe acidosis. An abnormal fetal heart rate tracing, similarly, is not in-and-of-itself predictive of fetal metabolic acidosis.

Knowing whether a fetus has only mild acidosis, or severe acidosis, has important implications. A fetus struck with bradycardia, for instance, will tolerate the complication much better if it has mild or no significant acidosis at the start than if it is on the precipice of shifting into severe acidosis. Knowledge of the degree of acidosis equips us to better predict and manage fetal compromise and avoid unnecessary operative deliveries.

Indeed, more research is needed to better understand the change in the level of fetal metabolic acidosis with both the progression of labor and with induced fetal heart rate changes. Yet even as we work to advance our knowledge, we have learned enough about fetal acidosis to be able to seek answers to several questions: Is what's happening to the heart rate affected by hypoxia? Does the tracing reflect the degree of acidosis? Where are we on the spectrum of acidosis?

Changes in Base Deficit

The values termed “base excess” or “base deficit” are used to quantify the magnitude of metabolic acidosis during normal stages of labor. A large positive base deficit—or a large negative base excess—indicates that the body's base buffers have been used up to buffer acids and that metabolic acidosis is present.

A base deficit of 12 mmol/L—or alternatively a base excess of −12 mmol/L—is widely accepted as the threshold for risk of acute brain injury. When we're looking at a tracing, our monitoring and management plans will differ significantly, therefore, for a fetus with a normal tracing and a base deficit of 2 mmol/L compared with a fetus who has a normal tracing and a base deficit of 8 mmol/L.

The average fetus enters labor slightly acidotic with a base deficit of approximately 2 mmol/L. During the latent phase of labor, which typically represents minimal stress, the fetus incurs no real change in base deficit. During the active phase, however, the stress of the labor causes the base deficit to increase by approximately 1 mmol/L every 3-6 hours, and during the second stage, the base deficit increases by approximately 1 mmol/L every hour. This means that by the end of the first stage of labor, the fetus has a base deficit of 4 mmol/L, on average. At the end of the second stage, the average baby is born with a base deficit of approximately 5 mmol/L.

The development of mild acidosis through the stages of normal labor is analogous to an adult walking, jogging, and then sprinting. Most of us would progressively use more oxygen than we can provide as we pick up the pace, spurring a conversion from aerobic to anaerobic metabolism that results in the production of lactic acid and consequent soreness—even aching pain—in our legs. For the fetus, the latent phase of labor is the equivalent of our walking, the active phase represents jogging, and the second stage is equivalent to a sprint.

During labor, lactic acid accumulation can lead to metabolic acidosis and a blunting of the vagal regulation of the fetal heart rate and consequent loss of accelerations, loss of variability between contractions, and other changes with possible long-term sequelae.

In monitoring labor, we want to know where we are on the spectrum of acidosis. Have we gone through the active phase, for example? Where are we in the second stage? Understanding where the fetus is on this spectrum prepares us to manage any changes—any additional acidosis related to fetal heart rate decelerations—that are superimposed on the background stress of the labor process.

Acidosis and Heart Rate Patterns

Research has confirmed not only degrees of hypoxemia and fetal base deficit values during the normal course of labor; it also has provided a window of knowledge into the changes in fetal acidosis in relation to particular fetal heart rate patterns.

Early decelerations are generally well tolerated by the fetus and probably do not result in any additional acidosis. These are believed to result from fetal head compression and a subsequent hormonal or vagal response.

Similarly, mild or moderate variable fetal heart rate decelerations, which are due to modest cord compression, are well tolerated if they occur at a reasonable frequency (such as every 3 minutes). The frequency of variable decelerations is critical as lactic acid generated during the variable deceleration may be cleared across the placenta during the periods between decelerations.

When variable heart rate decelerations are severe and of increasing frequency, however, the fetus can accumulate lactic acid—sometimes rapidly—depending on the frequency. A severe variable deceleration results from complete or near-complete umbilical cord occlusion and is typically defined as one that lasts for at least 60 seconds, during which the heart rate drops below 70 beats per minute

In a study we published this year with colleagues in Canada, we found that severe variable decelerations result in an increase in base deficit of 0.5 mmol/L per minute of cord occlusion. We also found, however, that metabolic acidosis is cleared at a rate of 0.1 mmol/L per minute of recovery, when fetal heart rate is normal and stress is reduced (Am. J. Obstet. Gynecol. 2009;200:200.e1-7).

Given these rates of acid accumulation and normalization, one can understand how acidosis may develop when repetitive, severe variable decelerations occur every 3 minutes, for instance. Past a certain frequency and severity, there simply isn't enough recovery time to allow the fetus to sufficiently correct the base deficit.

Although most of us will not actually be using these acid accumulation and recovery rates to calculate specific base deficits, an awareness of the principles can aid us in assessing fetal acidosis. The concept of recovery time is an important one. Again, knowing where your patient is on the spectrum of acidosis tells you how much “buffer time” you have if something goes wrong.

There is policy, sometimes attributed to midwives, that advocates letting the patient push only during every other contraction. Given what we've learned about the development of acidosis, when pushing is associated with severe variable decelerations, there may be an advantage to pushing every other contraction in order to permit sufficient recovery time and clearance of acid between the decelerations.

One of the signals that acidosis is progressing to a moderate level (approximately 8 mmol/L) is the change in severe variable decelerations from typical (having shoulders, a sharp drop, and a sharp rise) to atypical (a loss of shoulders, a U-shaped variable deceleration, or a slow return to baseline).

Another sign of moderate acidosis is a loss of variability between contractions. These heart rate patterns need more research, but in my experience a prolonged loss of variability between contractions (unrelated to the fetal sleep state) typically does not occur until the base deficit approaches 8 mmol/L or greater. Given that the risk of brain injury begins with a base deficit of 12 mmol/L, an observation of this change provides a buffer zone during which the patient can be even more closely monitored.

It used to be thought that late decelerations were extremely worrisome, but we have learned that these patterns are usually less threatening to the fetus's accumulation of metabolic acidosis than are severe variable decelerations.

When there is good baseline variability between the decelerations, the late deceleration often reflects a vagal-mediated response and probably involves no change in the level of acidosis. When there is a loss of variability between contractions, however, the late deceleration may reflect a hypoxia-induced response. Still, the rate of acidosis accumulation is typically less than it is with severe variable decelerations.

In general, the amount of acid accumulation with late decelerations is dependent on the frequency and severity of the decelerations; the accumulation of acidosis may range from a base deficit increase of 1 mmol/L every 5 minutes to an increase of just 1 mmol/L every 15 minutes.

One of the weak links in our understanding of fetal acidosis today is our inability to recognize preexisting acidosis or preexisting injury. We have little experience in identifying fetal heart rate patterns associated with preexisting hypoxic injuries.

Adding to the challenge is the knowledge that a post-term fetus or one with intrauterine growth restriction may begin labor with a slightly greater level of acidosis. Furthermore, fetuses with true sepsis or severe anemia may accumulate acid at an increased rate compared with normal fetuses.

Where We Stand

Practically, attempting to avoid injury by recognizing mild, moderate, and potentially severe levels of fetal acidosis means that one must carefully examine fetal heart rate tracings, not only for the time we are present in the room, but at least back to the time of our previous assessment. As much as is possible, we should understand what the entirety of the monitoring has shown.

We should attempt to factor in the known changes in fetal acidosis associated with normal stages of labor together with estimated changes in acidosis related to superimposed fetal heart rate decelerations. With an understanding of the progress and stage of labor, the current fetal heart rate pattern, and the approximate level of fetal metabolic acidosis, we will be best prepared to manage the pregnancy for an optimal outcome.

ELSEVIER GLOBAL MEDICAL NEWS

ELSEVIER GLOBAL MEDICAL NEWS

Fetal Heart Rate Monitoring

Over the years, we have endeavored to assess fetal well-being by a number of electronic and nonelectronic means with varying degrees of success. Of all these methods, fetal heart rate monitoring has withstood the test of time.

Our continued use of fetal heart rate monitoring as a means of assessing the fetus's biochemical and biophysical status has contributed much to our understanding of fetal well-being, or lack thereof. More recently, efforts have been made to better correlate variations in fetal heart rate to fetal well-being.

It is well known that the fetus is the final arbiter of intrauterine stress and may respond with compensatory mechanisms that may thwart various types of stresses. In such a scenario, the fetus may not manifest a compromised state, despite potentially harmful stress conditions. On the other hand, another fetus facing similarly stressful intrauterine conditions may struggle, exhibiting fetal distress or worse.

In reality, what matters most is the response of the fetus and not the stressful condition per se. Every attempt to monitor fetal well-being has been focused, therefore, on the response of the fetus to various types of stress. Because we're unable to conduct biochemical testing on a real-time or continuous basis, fetal heart rate monitoring often has been used as a surrogate for the biochemical adaptations by the fetus to intrauterine stress conditions.

Fetal heart rate monitoring, thus, becomes a very important diagnostic tool because the decisions that physicians make and the interventions that they undertake often are based on their interpretation of the fetal heart rate tracings. Such decisions are critical to the overall outcome of the fetus.

It is in this light that we are dedicating a Master Class to the subject of fetal acidosis and fetal heart rate assessment and have invited Dr. Michael G. Ross to serve as our guest professor this month. Dr. Ross is the chair of obstetrics and gynecology at the Harbor-UCLA Medical Center in Torrance, Calif., and professor and vice chair of obstetrics and gynecology at the David Geffen School of Medicine at the University of California, Los Angeles.

Dr. Ross's exceptional article on this topic delineates the mechanisms of fetal metabolic acidosis and its effects on fetal well-being. He also offers valuable insights on how fetal heart rate tracings might be better utilized as a powerful tool for detecting and predicting where a fetus may lie along the acidosis spectrum during various stages of labor so that interventions may be implemented to prevent severe acidosis and associated injury to the fetus.

For more than a decade, the capacity to perform cervicoisthmic cerclage by laparoscopy has provided a minimally invasive alternative for some women to the often-complicated traditional abdominal approach that was first reported in 1965.

With a laparoscopic cerclage performed by 12 weeks' gestation, patients for whom conventional vaginal cerclage has failed or is not possible have had successful deliveries without the extended midline incision, considerable hospital stays, or significant risks to the mother and fetus that are associated with the conventional abdominal approach.

Laparoscopic cerclage is a highly innovative procedure that has offered hope and delivered good outcomes. Still, one has to ask, are we really achieving all we can for our patients?

Does it not make sense to intervene earlier—before pregnancy—in certain high-risk women with anatomically altered or deficient cervices and/or with previous failures of conventional vaginal cerclages for cervical incompetence?

The notion of “interval cerclage” as opposed to interventional or “rescue” cerclage is an idea whose time has come. There are significant numbers of women who would substantially benefit from the insertion of a cervicoisthmic cerclage in the nonpregnant state—when the surgeon is not constrained by the contents, size, or fragility of the gravid uterus or challenged by the marked pelvic vascularity and other physiological changes of pregnancy.

The pregnant women who have undergone laparoscopic cervicoisthmic cerclage under our care have experienced failures of conventional vaginal cerclages, and many have suffered repeated second-trimester losses.

These high-stakes cases involving patients who are desperate for a successful pregnancy have led us to believe that one failure is enough—or, in the cases of patients who have other clear risk factors such as anatomically altered cervices, that one failure is too many.

As we move further into the era of reproductive technology and extended reproductive years, pregnancies are increasingly high-stakes experiences with a limited number of assisted cycles. Women do not have time to spare and do not want to take risks. Older women seeking to have a child not only are more likely to have had in vitro fertilization and other fertility treatments, they also are more likely to have had a loop electrosurgical excision procedure (LEEP), cone biopsy, or other procedure that has been associated with cervical incompetence. Many of these women are possible candidates for interval cerclage.

This type of cerclage requires a new thought process—a new mind-set—as well as new and creative collaboration between skilled laparoscopic surgeons and the perinatologists who are following and counseling these patients.

By working in teams, with the perinatologist cultivating a relationship with an experienced laparoscopic surgeon, specialists can work together to bring the option of interval cerclage into discussions with patients who have poor obstetric histories due to cervical incompetence or serious risk factors associated with poor pregnancy outcomes, and then see the procedure through when it is deemed worthwhile and desirable.

In our experience, once we met each other and became aware of each other's interests and expertise, it seemed only natural to collaborate and offer these patients interval laparoscopic cerclage.

The Benefits

Ironically, we have shifted in the last 5–10 years from early-pregnancy cerclage based largely on history toward cerclage that is performed based on ultrasound measurement of cervical length during pregnancy. Cervical change rarely occurs before 12–14 weeks' gestation, which means that by the time of “discovery” of a short cervical length, cerclage is all the more difficult and risky to perform.

The advantages to an interval approach to cerclage are numerous: The surgeon does not have to contend with the burden of an intrauterine pregnancy associated with the increased pelvic vascularity of pregnancy (up to 25% of the maternal circulation moves through the pelvis at this time) or the increased uterine size, which can be constraining, particularly for a laparoscopic approach.

Beyond 12–14 weeks, in fact, it becomes almost impossible with a laparoscopic approach to gently manipulate the uterus to see both the front and back of the lower uterine segment. Avoiding interventions close to the gravid uterus, of course, is always desirable. And with an interval cerclage, healing is typically completed by the time pregnancy occurs.

For a surgeon with advanced laparoscopic experience, the laparoscopic approach to a cervicoisthmic cerclage is generally much easier and safer than a “true” transvaginal cervicoisthmic cerclage.

Some experienced surgeons—though very few—have performed classical cervicoisthmic cerclage transvaginally during early pregnancy in the belief that a higher cerclage placement is more effective than a lower one. When the stitch is placed high at the level of the cervicoisthmic junction—or even higher—and above the level of the cardinal ligaments, the stitch is less likely to slip down along the cervix. It is supported from underneath by the cardinal ligaments.

The normal cervix can be anatomically represented by the letter Y. Then imagine it becoming the letter V, and then the letter U. This is the type of change that an incompetent cervix undergoes. If we can prevent, as much as possible, the formation of the V, then these changes are less likely to occur.

Although there is no scientific evidence, per se, to support this “higher is better” belief, it makes intrinsic sense, and there are data to suggest better outcomes with this higher stitch placement. Our experience shows that the vast majority of patients with previous failed cerclages had the conventional vaginal procedure, a simple Mersilene purse-string stitch placed low in the cervical stroma, not approximating the internal os where deformities typically are.

The problem is that transvaginal insertion of a cervical suture high at the level of the cervicoisthmic junction is complex and fraught with the risk of complications because the high stitch placement involves mobilizing and climbing up under the bladder, in close proximity to the vasculature of the uterus. Some surgeons have had success, but in general, what needs to be done exceeds the skills and experience of most.

In patients who are pregnant, traditional abdominal cervicoisthmic cerclage—the other alternative—has been associated with severe complications, such as hemorrhage and pregnancy loss. (Our sense is that few of these surgeries are performed because the stakes are so high and the risks so real.) Patients who are not pregnant still face an extended midline incision and a considerable hospital stay.

With laparoscopy, we can achieve the higher is better principle less invasively with more ease and superior precision. Compared with the vaginal or laparotomic approach, the laparoscopic method provides less trauma to the gravid uterus and unparalleled visual and mechanical access to the key anatomical structures either incorporated or potentially injured during cervicoisthmic cerclage. Placing the stitch precisely at the correct level is the most important element of this procedure.

Moreover, laparoscopic placement of the tape may reduce the recognized incidence of postoperative chorioamnionitis by removing the presence of a foreign body in the vagina. A first-trimester loss can usually be evacuated using conventional techniques, while elimination of more-advanced gestations can be simply facilitated by removing the stitch laparoscopically.

Whereas patients undergoing laparoscopic cervicoisthmic cerclage still must have a laparotomy at the end, because the cerclage is a permanent suture and necessitates delivery by cesarean section, morbidity and mortality risks are cut in half compared with patients undergoing two traditional abdominal surgeries.

Success rates after cervical cerclage are high, up to 87%. The interpretation of outcome is complex, however, because of the conflicting indications for treatment and differing timing of the procedure (before or during pregnancy). Quality research comparing approaches in patients with high-risk indications has been difficult to conduct as well, in part because patients who have had recurrent pregnancy failures are reluctant to participate in such studies.

Much of the available data, moreover, is confounded by a multiplicity of high-risk factors and variables related to recurrent pregnancy loss.

Dr. Brill's Technique

Patients are placed in a modified dorsal lithotomy position, and a No. 12 Foley catheter is inserted for bladder drainage. When the patient is pregnant, I perform an assiduous pelvic exam to assess for advanced cervical dilation.

In gravid patients, the largest cervical cup from a disassembled KOH colpotomizer is used to laparoscopically delineate the vaginal fornices and atraumatically manipulate the cervix and lower uterine segment by using two ring forceps secured opposite one another to the outer ring.

Fetal heart tones are documented before the laparoscopic procedure is initiated. The risk of incidental trauma to the gravid uterus is minimized by using open laparoscopy to attain peritoneal access.

The intra-abdominal pressure is strictly limited to 12 mm Hg, and all patients are placed in a maximally tolerated Trendelenburg position. I then determine the feasibility of the procedure based on an assessment of anatomical access and ready mobility of the gravid uterus.

Two 5-mm midquadrant ports are placed under direct vision, each lateral to the respective epigastric arteries and slightly below the level of the umbilicus. A 10-mm port is carefully introduced in the midline, one to two finger breadths above the pubic ramus.

The vesicouterine peritoneum is dissected transversely using either a monopolar spatula electrode or the 5-mm curved Harmonic shears. The uterus is mobilized using the pericervical cup and a 5-mm blunt probe.

The bladder is then minimally dissected off the lower uterine segment to reveal native pubocervical fascia and the course of the uterine vessels. With a combination of blunt and sharp dissection, an adequate surgical window is created medial to each set of uterine vessels at the level of the isthmus (

A 5-mm Mersilene tape is prepared by removing the attached curved needles, and the suture is then introduced into the posterior pelvis through the 10-mm suprapubic port. A 10-mm right-angle forceps through the suprapubic port is used to grasp and position the ligature around the lower uterine segment at the level of the isthmus by first piercing through the surgical windows in an anterior-to-posterior direction to then grasp and withdraw each end of the suture back into the vesicouterine space.

Care must be taken to confirm that the tape is flatly applied to the posterior lower uterine segment. The suture is then tied intracorporeally on the pubocervical fascia with at least five knots (

Whenever possible the vesicouterine peritoneal defect is closed with a running suture and tied extracorporeally. A vaginal exam is then performed to ensure that the suture ligature is above the level of the vaginal fornices. Fetal heart tones are once again documented.

In nongravid patients, a conventional uterine elevator is used for uterine manipulation. Conventional closed laparoscopic techniques are used for peritoneal access. Lower-quadrant trocar sites are lateral to the inferior epigastric vessels and usually at the level of the anterior superior iliac spines.

Whereas I employ the same dissection and suture ligature techniques used during the early cases of interval cerclage, more recently I have employed the classical technique using the two attached 48-mm needles to direct the Mersilene tape through the broad ligament just medial to the uterine vessels at the level of the isthmus.

After dissection of the anterior lower uterine segment to mobilize the bladder and to expose the uterine vessels, the uterus is anteverted and windows are created in the posterior broad ligament to expose the course of the uterine vessels.

The large needles still attached to the tape are introduced into the abdomen through one of the exposed lateral trocar sites by successively grasping each end of the suture several centimeters from the swedge point and then directing the needles through the abdominal wall and then into the peritoneal cavity under direct vision. Using the uterine elevator to retroflex the uterus and then expose the anterior lower uterine segment, I drive each needle medial to the uterine vessels perpendicularly to exit posteriorly as the uterus is simultaneously anteflexed to expose the broad ligament windows (

Once tightened around the lower uterine segment at the level of the isthmus, the tape ends are cut to release the needles, which are then extracted through the open suprapubic port site by reversing the maneuver used for their introduction. Care must be taken to confirm that the tape is flatly applied to the anterior lower uterine segment. The ligature ends are then tied together posteriorly by intracorporeal knot tying and are not peritonealized (

Cervical Cerclage

Cervical cerclage involves the placement of sutures, wires, or synthetic tape to mechanically increase the tensile strength of the cervix. The procedure is done either electively or emergently (rescue) to reduce the risk of cervical insufficiency and the resultant second-trimester recurrent pregnancy loss.

After reviewing the 2006 article in the American Journal of Obstetrics and Gynecology by Dr. Roberto Romero and his associates, the subsequent letter to the editors by Sietske M. Althuisius, Ph.D., and Pieter Hummel, Ph.D., and the author's reply, debate still lingers about whether credit should be given to Lazare Rivière, in his 1655 article published in Latin, for the first description of cervical insufficiency. By 1678, A. Cole, N. Culpepper, and W. Rowland described this entity in their book “Practice of Physick”:“The second fault in women which hindered conception is when the seed is not retained or the orifice of the womb is so slack that it cannot rightly contract itself to keep in the seed; which is chiefly caused by abortion or hard labor and childbirth, whereby the fibers of the womb are broken in pieces one from another and the inner orifice of the womb overmuch slackened.”

Three hundred years later, in an 1865 letter to the editor of the Lancet, G.T. Gream described a patient who had previously undergone cervical surgery “as a cure for dysmenorrhea and sterility.” Gream wrote: “She had arrived at about the fourth month of pregnancy; telling me—without, however, attributing her pregnancy to the operation—that the uterus had 6 years before been operated upon; and so complete had been the division of the cervix that the finger could readily be introduced into the uterine cavity, and the membranes of the ovum could be touched, as they can be sometimes during the last days of gestation. … According to prognostications, abortion resulted but a few weeks afterwards, from the inability of the uterus to retain its contents.”

V.N. Shirodkar, professor of midwifery and gynecology at Grant Medical College in Bombay, India, is credited with the introduction of cervical cerclage into modern obstetric practice in 1955. The need was based on his finding that “some women abort[ed] repeatedly between the fourth and seventh month and no amount of rest and treatment with hormones seemed to help them in retaining the product of conception.” This was immediately followed by Ian McDonald's report from the Royal Melbourne Hospital on his cerclage experience in 70 patients in 1957.

In this edition of Master Class in Gynecologic Surgery, I have asked Dr. Andrew I. Brill, director of minimally invasive gynecology, reparative pelvic surgery, and training at the California Pacific Medical Center, San Francisco, and former president of the AAGL, as well as Dr. Michael Katz, clinical professor of obstetrics, gynecology, and reproductive sciences, University of California, San Francisco, and chief of perinatal services at California Pacific Medical Center, to discuss interval cervicoisthmic cerclage, with an emphasis on a laparoscopic approach.

Dr. Brill coauthored the first report on a laparoscopic preconceptional cervicoisthmic cerclage in a woman with repeated midtrimester cervical cerclage failure for the Journal of Minimally Invasive Gynecology. Despite being an experienced vaginal surgeon and having extensive experience in classical transvaginal cervicoisthmic cerclage, upon observing Dr. Brill's laparoscopic technique, Dr. Katz became familiar with the benefits of this approach. It is our intent that after reading this edition of the Master Class in Gynecologic Surgery, you will, too.

Dr. Brill's Experience

Over the last 5 years, I have performed laparoscopic cervicoisthmic cerclage under general anesthesia in 23 patients who had documented histories consistent with cervical incompetence.

There have been 18 successful deliveries (at a mean gestational age of 36.6 weeks) with a fetal salvage rate of 78% (18/23), compared with 7.3% (6/82) during all of the patients' previous intrauterine pregnancies. In 12 of the 23 cases (52%), the cerclage was performed preconceptionally as an interval procedure. In the remaining 11, cerclage was performed during early pregnancy (at a mean gestational age of 12 weeks). Three of the cases were ultimately completed laparotomically—two secondary to pelvic adhesions and the other secondary to bleeding. In the 11 pregnant patients, only two losses occurred intraoperatively—one secondary to advanced cervical dilation and one for undetermined reasons 10 days postoperatively.

For more than a decade, the capacity to perform cervicoisthmic cerclage by laparoscopy has provided a minimally invasive alternative for some women to the often-complicated traditional abdominal approach that was first reported in 1965.

With a laparoscopic cerclage performed by 12 weeks' gestation, patients for whom conventional vaginal cerclage has failed or is not possible have had successful deliveries without the extended midline incision, considerable hospital stays, or significant risks to the mother and fetus that are associated with the conventional abdominal approach.

Laparoscopic cerclage is a highly innovative procedure that has offered hope and delivered good outcomes. Still, one has to ask, are we really achieving all we can for our patients?

Does it not make sense to intervene earlier—before pregnancy—in certain high-risk women with anatomically altered or deficient cervices and/or with previous failures of conventional vaginal cerclages for cervical incompetence?

The notion of “interval cerclage” as opposed to interventional or “rescue” cerclage is an idea whose time has come. There are significant numbers of women who would substantially benefit from the insertion of a cervicoisthmic cerclage in the nonpregnant state—when the surgeon is not constrained by the contents, size, or fragility of the gravid uterus or challenged by the marked pelvic vascularity and other physiological changes of pregnancy.

The pregnant women who have undergone laparoscopic cervicoisthmic cerclage under our care have experienced failures of conventional vaginal cerclages, and many have suffered repeated second-trimester losses.

These high-stakes cases involving patients who are desperate for a successful pregnancy have led us to believe that one failure is enough—or, in the cases of patients who have other clear risk factors such as anatomically altered cervices, that one failure is too many.

As we move further into the era of reproductive technology and extended reproductive years, pregnancies are increasingly high-stakes experiences with a limited number of assisted cycles. Women do not have time to spare and do not want to take risks. Older women seeking to have a child not only are more likely to have had in vitro fertilization and other fertility treatments, they also are more likely to have had a loop electrosurgical excision procedure (LEEP), cone biopsy, or other procedure that has been associated with cervical incompetence. Many of these women are possible candidates for interval cerclage.

This type of cerclage requires a new thought process—a new mind-set—as well as new and creative collaboration between skilled laparoscopic surgeons and the perinatologists who are following and counseling these patients.

By working in teams, with the perinatologist cultivating a relationship with an experienced laparoscopic surgeon, specialists can work together to bring the option of interval cerclage into discussions with patients who have poor obstetric histories due to cervical incompetence or serious risk factors associated with poor pregnancy outcomes, and then see the procedure through when it is deemed worthwhile and desirable.

In our experience, once we met each other and became aware of each other's interests and expertise, it seemed only natural to collaborate and offer these patients interval laparoscopic cerclage.

The Benefits

Ironically, we have shifted in the last 5–10 years from early-pregnancy cerclage based largely on history toward cerclage that is performed based on ultrasound measurement of cervical length during pregnancy. Cervical change rarely occurs before 12–14 weeks' gestation, which means that by the time of “discovery” of a short cervical length, cerclage is all the more difficult and risky to perform.

The advantages to an interval approach to cerclage are numerous: The surgeon does not have to contend with the burden of an intrauterine pregnancy associated with the increased pelvic vascularity of pregnancy (up to 25% of the maternal circulation moves through the pelvis at this time) or the increased uterine size, which can be constraining, particularly for a laparoscopic approach.

Beyond 12–14 weeks, in fact, it becomes almost impossible with a laparoscopic approach to gently manipulate the uterus to see both the front and back of the lower uterine segment. Avoiding interventions close to the gravid uterus, of course, is always desirable. And with an interval cerclage, healing is typically completed by the time pregnancy occurs.

For a surgeon with advanced laparoscopic experience, the laparoscopic approach to a cervicoisthmic cerclage is generally much easier and safer than a “true” transvaginal cervicoisthmic cerclage.

Some experienced surgeons—though very few—have performed classical cervicoisthmic cerclage transvaginally during early pregnancy in the belief that a higher cerclage placement is more effective than a lower one. When the stitch is placed high at the level of the cervicoisthmic junction—or even higher—and above the level of the cardinal ligaments, the stitch is less likely to slip down along the cervix. It is supported from underneath by the cardinal ligaments.

The normal cervix can be anatomically represented by the letter Y. Then imagine it becoming the letter V, and then the letter U. This is the type of change that an incompetent cervix undergoes. If we can prevent, as much as possible, the formation of the V, then these changes are less likely to occur.

Although there is no scientific evidence, per se, to support this “higher is better” belief, it makes intrinsic sense, and there are data to suggest better outcomes with this higher stitch placement. Our experience shows that the vast majority of patients with previous failed cerclages had the conventional vaginal procedure, a simple Mersilene purse-string stitch placed low in the cervical stroma, not approximating the internal os where deformities typically are.

The problem is that transvaginal insertion of a cervical suture high at the level of the cervicoisthmic junction is complex and fraught with the risk of complications because the high stitch placement involves mobilizing and climbing up under the bladder, in close proximity to the vasculature of the uterus. Some surgeons have had success, but in general, what needs to be done exceeds the skills and experience of most.

In patients who are pregnant, traditional abdominal cervicoisthmic cerclage—the other alternative—has been associated with severe complications, such as hemorrhage and pregnancy loss. (Our sense is that few of these surgeries are performed because the stakes are so high and the risks so real.) Patients who are not pregnant still face an extended midline incision and a considerable hospital stay.

With laparoscopy, we can achieve the higher is better principle less invasively with more ease and superior precision. Compared with the vaginal or laparotomic approach, the laparoscopic method provides less trauma to the gravid uterus and unparalleled visual and mechanical access to the key anatomical structures either incorporated or potentially injured during cervicoisthmic cerclage. Placing the stitch precisely at the correct level is the most important element of this procedure.

Moreover, laparoscopic placement of the tape may reduce the recognized incidence of postoperative chorioamnionitis by removing the presence of a foreign body in the vagina. A first-trimester loss can usually be evacuated using conventional techniques, while elimination of more-advanced gestations can be simply facilitated by removing the stitch laparoscopically.

Whereas patients undergoing laparoscopic cervicoisthmic cerclage still must have a laparotomy at the end, because the cerclage is a permanent suture and necessitates delivery by cesarean section, morbidity and mortality risks are cut in half compared with patients undergoing two traditional abdominal surgeries.

Success rates after cervical cerclage are high, up to 87%. The interpretation of outcome is complex, however, because of the conflicting indications for treatment and differing timing of the procedure (before or during pregnancy). Quality research comparing approaches in patients with high-risk indications has been difficult to conduct as well, in part because patients who have had recurrent pregnancy failures are reluctant to participate in such studies.

Much of the available data, moreover, is confounded by a multiplicity of high-risk factors and variables related to recurrent pregnancy loss.

Dr. Brill's Technique

Patients are placed in a modified dorsal lithotomy position, and a No. 12 Foley catheter is inserted for bladder drainage. When the patient is pregnant, I perform an assiduous pelvic exam to assess for advanced cervical dilation.

In gravid patients, the largest cervical cup from a disassembled KOH colpotomizer is used to laparoscopically delineate the vaginal fornices and atraumatically manipulate the cervix and lower uterine segment by using two ring forceps secured opposite one another to the outer ring.

Fetal heart tones are documented before the laparoscopic procedure is initiated. The risk of incidental trauma to the gravid uterus is minimized by using open laparoscopy to attain peritoneal access.

The intra-abdominal pressure is strictly limited to 12 mm Hg, and all patients are placed in a maximally tolerated Trendelenburg position. I then determine the feasibility of the procedure based on an assessment of anatomical access and ready mobility of the gravid uterus.

Two 5-mm midquadrant ports are placed under direct vision, each lateral to the respective epigastric arteries and slightly below the level of the umbilicus. A 10-mm port is carefully introduced in the midline, one to two finger breadths above the pubic ramus.

The vesicouterine peritoneum is dissected transversely using either a monopolar spatula electrode or the 5-mm curved Harmonic shears. The uterus is mobilized using the pericervical cup and a 5-mm blunt probe.

The bladder is then minimally dissected off the lower uterine segment to reveal native pubocervical fascia and the course of the uterine vessels. With a combination of blunt and sharp dissection, an adequate surgical window is created medial to each set of uterine vessels at the level of the isthmus (

A 5-mm Mersilene tape is prepared by removing the attached curved needles, and the suture is then introduced into the posterior pelvis through the 10-mm suprapubic port. A 10-mm right-angle forceps through the suprapubic port is used to grasp and position the ligature around the lower uterine segment at the level of the isthmus by first piercing through the surgical windows in an anterior-to-posterior direction to then grasp and withdraw each end of the suture back into the vesicouterine space.

Care must be taken to confirm that the tape is flatly applied to the posterior lower uterine segment. The suture is then tied intracorporeally on the pubocervical fascia with at least five knots (

Whenever possible the vesicouterine peritoneal defect is closed with a running suture and tied extracorporeally. A vaginal exam is then performed to ensure that the suture ligature is above the level of the vaginal fornices. Fetal heart tones are once again documented.

In nongravid patients, a conventional uterine elevator is used for uterine manipulation. Conventional closed laparoscopic techniques are used for peritoneal access. Lower-quadrant trocar sites are lateral to the inferior epigastric vessels and usually at the level of the anterior superior iliac spines.

Whereas I employ the same dissection and suture ligature techniques used during the early cases of interval cerclage, more recently I have employed the classical technique using the two attached 48-mm needles to direct the Mersilene tape through the broad ligament just medial to the uterine vessels at the level of the isthmus.

After dissection of the anterior lower uterine segment to mobilize the bladder and to expose the uterine vessels, the uterus is anteverted and windows are created in the posterior broad ligament to expose the course of the uterine vessels.

The large needles still attached to the tape are introduced into the abdomen through one of the exposed lateral trocar sites by successively grasping each end of the suture several centimeters from the swedge point and then directing the needles through the abdominal wall and then into the peritoneal cavity under direct vision. Using the uterine elevator to retroflex the uterus and then expose the anterior lower uterine segment, I drive each needle medial to the uterine vessels perpendicularly to exit posteriorly as the uterus is simultaneously anteflexed to expose the broad ligament windows (

Once tightened around the lower uterine segment at the level of the isthmus, the tape ends are cut to release the needles, which are then extracted through the open suprapubic port site by reversing the maneuver used for their introduction. Care must be taken to confirm that the tape is flatly applied to the anterior lower uterine segment. The ligature ends are then tied together posteriorly by intracorporeal knot tying and are not peritonealized (

Cervical Cerclage

Cervical cerclage involves the placement of sutures, wires, or synthetic tape to mechanically increase the tensile strength of the cervix. The procedure is done either electively or emergently (rescue) to reduce the risk of cervical insufficiency and the resultant second-trimester recurrent pregnancy loss.

After reviewing the 2006 article in the American Journal of Obstetrics and Gynecology by Dr. Roberto Romero and his associates, the subsequent letter to the editors by Sietske M. Althuisius, Ph.D., and Pieter Hummel, Ph.D., and the author's reply, debate still lingers about whether credit should be given to Lazare Rivière, in his 1655 article published in Latin, for the first description of cervical insufficiency. By 1678, A. Cole, N. Culpepper, and W. Rowland described this entity in their book “Practice of Physick”:“The second fault in women which hindered conception is when the seed is not retained or the orifice of the womb is so slack that it cannot rightly contract itself to keep in the seed; which is chiefly caused by abortion or hard labor and childbirth, whereby the fibers of the womb are broken in pieces one from another and the inner orifice of the womb overmuch slackened.”

Three hundred years later, in an 1865 letter to the editor of the Lancet, G.T. Gream described a patient who had previously undergone cervical surgery “as a cure for dysmenorrhea and sterility.” Gream wrote: “She had arrived at about the fourth month of pregnancy; telling me—without, however, attributing her pregnancy to the operation—that the uterus had 6 years before been operated upon; and so complete had been the division of the cervix that the finger could readily be introduced into the uterine cavity, and the membranes of the ovum could be touched, as they can be sometimes during the last days of gestation. … According to prognostications, abortion resulted but a few weeks afterwards, from the inability of the uterus to retain its contents.”

V.N. Shirodkar, professor of midwifery and gynecology at Grant Medical College in Bombay, India, is credited with the introduction of cervical cerclage into modern obstetric practice in 1955. The need was based on his finding that “some women abort[ed] repeatedly between the fourth and seventh month and no amount of rest and treatment with hormones seemed to help them in retaining the product of conception.” This was immediately followed by Ian McDonald's report from the Royal Melbourne Hospital on his cerclage experience in 70 patients in 1957.

In this edition of Master Class in Gynecologic Surgery, I have asked Dr. Andrew I. Brill, director of minimally invasive gynecology, reparative pelvic surgery, and training at the California Pacific Medical Center, San Francisco, and former president of the AAGL, as well as Dr. Michael Katz, clinical professor of obstetrics, gynecology, and reproductive sciences, University of California, San Francisco, and chief of perinatal services at California Pacific Medical Center, to discuss interval cervicoisthmic cerclage, with an emphasis on a laparoscopic approach.

Dr. Brill coauthored the first report on a laparoscopic preconceptional cervicoisthmic cerclage in a woman with repeated midtrimester cervical cerclage failure for the Journal of Minimally Invasive Gynecology. Despite being an experienced vaginal surgeon and having extensive experience in classical transvaginal cervicoisthmic cerclage, upon observing Dr. Brill's laparoscopic technique, Dr. Katz became familiar with the benefits of this approach. It is our intent that after reading this edition of the Master Class in Gynecologic Surgery, you will, too.

Dr. Brill's Experience

Over the last 5 years, I have performed laparoscopic cervicoisthmic cerclage under general anesthesia in 23 patients who had documented histories consistent with cervical incompetence.

There have been 18 successful deliveries (at a mean gestational age of 36.6 weeks) with a fetal salvage rate of 78% (18/23), compared with 7.3% (6/82) during all of the patients' previous intrauterine pregnancies. In 12 of the 23 cases (52%), the cerclage was performed preconceptionally as an interval procedure. In the remaining 11, cerclage was performed during early pregnancy (at a mean gestational age of 12 weeks). Three of the cases were ultimately completed laparotomically—two secondary to pelvic adhesions and the other secondary to bleeding. In the 11 pregnant patients, only two losses occurred intraoperatively—one secondary to advanced cervical dilation and one for undetermined reasons 10 days postoperatively.

For more than a decade, the capacity to perform cervicoisthmic cerclage by laparoscopy has provided a minimally invasive alternative for some women to the often-complicated traditional abdominal approach that was first reported in 1965.

With a laparoscopic cerclage performed by 12 weeks' gestation, patients for whom conventional vaginal cerclage has failed or is not possible have had successful deliveries without the extended midline incision, considerable hospital stays, or significant risks to the mother and fetus that are associated with the conventional abdominal approach.

Laparoscopic cerclage is a highly innovative procedure that has offered hope and delivered good outcomes. Still, one has to ask, are we really achieving all we can for our patients?

Does it not make sense to intervene earlier—before pregnancy—in certain high-risk women with anatomically altered or deficient cervices and/or with previous failures of conventional vaginal cerclages for cervical incompetence?

The notion of “interval cerclage” as opposed to interventional or “rescue” cerclage is an idea whose time has come. There are significant numbers of women who would substantially benefit from the insertion of a cervicoisthmic cerclage in the nonpregnant state—when the surgeon is not constrained by the contents, size, or fragility of the gravid uterus or challenged by the marked pelvic vascularity and other physiological changes of pregnancy.

The pregnant women who have undergone laparoscopic cervicoisthmic cerclage under our care have experienced failures of conventional vaginal cerclages, and many have suffered repeated second-trimester losses.

These high-stakes cases involving patients who are desperate for a successful pregnancy have led us to believe that one failure is enough—or, in the cases of patients who have other clear risk factors such as anatomically altered cervices, that one failure is too many.

As we move further into the era of reproductive technology and extended reproductive years, pregnancies are increasingly high-stakes experiences with a limited number of assisted cycles. Women do not have time to spare and do not want to take risks. Older women seeking to have a child not only are more likely to have had in vitro fertilization and other fertility treatments, they also are more likely to have had a loop electrosurgical excision procedure (LEEP), cone biopsy, or other procedure that has been associated with cervical incompetence. Many of these women are possible candidates for interval cerclage.

This type of cerclage requires a new thought process—a new mind-set—as well as new and creative collaboration between skilled laparoscopic surgeons and the perinatologists who are following and counseling these patients.

By working in teams, with the perinatologist cultivating a relationship with an experienced laparoscopic surgeon, specialists can work together to bring the option of interval cerclage into discussions with patients who have poor obstetric histories due to cervical incompetence or serious risk factors associated with poor pregnancy outcomes, and then see the procedure through when it is deemed worthwhile and desirable.

In our experience, once we met each other and became aware of each other's interests and expertise, it seemed only natural to collaborate and offer these patients interval laparoscopic cerclage.

The Benefits

Ironically, we have shifted in the last 5–10 years from early-pregnancy cerclage based largely on history toward cerclage that is performed based on ultrasound measurement of cervical length during pregnancy. Cervical change rarely occurs before 12–14 weeks' gestation, which means that by the time of “discovery” of a short cervical length, cerclage is all the more difficult and risky to perform.

The advantages to an interval approach to cerclage are numerous: The surgeon does not have to contend with the burden of an intrauterine pregnancy associated with the increased pelvic vascularity of pregnancy (up to 25% of the maternal circulation moves through the pelvis at this time) or the increased uterine size, which can be constraining, particularly for a laparoscopic approach.

Beyond 12–14 weeks, in fact, it becomes almost impossible with a laparoscopic approach to gently manipulate the uterus to see both the front and back of the lower uterine segment. Avoiding interventions close to the gravid uterus, of course, is always desirable. And with an interval cerclage, healing is typically completed by the time pregnancy occurs.

For a surgeon with advanced laparoscopic experience, the laparoscopic approach to a cervicoisthmic cerclage is generally much easier and safer than a “true” transvaginal cervicoisthmic cerclage.

Some experienced surgeons—though very few—have performed classical cervicoisthmic cerclage transvaginally during early pregnancy in the belief that a higher cerclage placement is more effective than a lower one. When the stitch is placed high at the level of the cervicoisthmic junction—or even higher—and above the level of the cardinal ligaments, the stitch is less likely to slip down along the cervix. It is supported from underneath by the cardinal ligaments.

The normal cervix can be anatomically represented by the letter Y. Then imagine it becoming the letter V, and then the letter U. This is the type of change that an incompetent cervix undergoes. If we can prevent, as much as possible, the formation of the V, then these changes are less likely to occur.

Although there is no scientific evidence, per se, to support this “higher is better” belief, it makes intrinsic sense, and there are data to suggest better outcomes with this higher stitch placement. Our experience shows that the vast majority of patients with previous failed cerclages had the conventional vaginal procedure, a simple Mersilene purse-string stitch placed low in the cervical stroma, not approximating the internal os where deformities typically are.

The problem is that transvaginal insertion of a cervical suture high at the level of the cervicoisthmic junction is complex and fraught with the risk of complications because the high stitch placement involves mobilizing and climbing up under the bladder, in close proximity to the vasculature of the uterus. Some surgeons have had success, but in general, what needs to be done exceeds the skills and experience of most.

In patients who are pregnant, traditional abdominal cervicoisthmic cerclage—the other alternative—has been associated with severe complications, such as hemorrhage and pregnancy loss. (Our sense is that few of these surgeries are performed because the stakes are so high and the risks so real.) Patients who are not pregnant still face an extended midline incision and a considerable hospital stay.

With laparoscopy, we can achieve the higher is better principle less invasively with more ease and superior precision. Compared with the vaginal or laparotomic approach, the laparoscopic method provides less trauma to the gravid uterus and unparalleled visual and mechanical access to the key anatomical structures either incorporated or potentially injured during cervicoisthmic cerclage. Placing the stitch precisely at the correct level is the most important element of this procedure.

Moreover, laparoscopic placement of the tape may reduce the recognized incidence of postoperative chorioamnionitis by removing the presence of a foreign body in the vagina. A first-trimester loss can usually be evacuated using conventional techniques, while elimination of more-advanced gestations can be simply facilitated by removing the stitch laparoscopically.

Whereas patients undergoing laparoscopic cervicoisthmic cerclage still must have a laparotomy at the end, because the cerclage is a permanent suture and necessitates delivery by cesarean section, morbidity and mortality risks are cut in half compared with patients undergoing two traditional abdominal surgeries.

Success rates after cervical cerclage are high, up to 87%. The interpretation of outcome is complex, however, because of the conflicting indications for treatment and differing timing of the procedure (before or during pregnancy). Quality research comparing approaches in patients with high-risk indications has been difficult to conduct as well, in part because patients who have had recurrent pregnancy failures are reluctant to participate in such studies.

Much of the available data, moreover, is confounded by a multiplicity of high-risk factors and variables related to recurrent pregnancy loss.

Dr. Brill's Technique

Patients are placed in a modified dorsal lithotomy position, and a No. 12 Foley catheter is inserted for bladder drainage. When the patient is pregnant, I perform an assiduous pelvic exam to assess for advanced cervical dilation.

In gravid patients, the largest cervical cup from a disassembled KOH colpotomizer is used to laparoscopically delineate the vaginal fornices and atraumatically manipulate the cervix and lower uterine segment by using two ring forceps secured opposite one another to the outer ring.

Fetal heart tones are documented before the laparoscopic procedure is initiated. The risk of incidental trauma to the gravid uterus is minimized by using open laparoscopy to attain peritoneal access.

The intra-abdominal pressure is strictly limited to 12 mm Hg, and all patients are placed in a maximally tolerated Trendelenburg position. I then determine the feasibility of the procedure based on an assessment of anatomical access and ready mobility of the gravid uterus.

Two 5-mm midquadrant ports are placed under direct vision, each lateral to the respective epigastric arteries and slightly below the level of the umbilicus. A 10-mm port is carefully introduced in the midline, one to two finger breadths above the pubic ramus.

The vesicouterine peritoneum is dissected transversely using either a monopolar spatula electrode or the 5-mm curved Harmonic shears. The uterus is mobilized using the pericervical cup and a 5-mm blunt probe.

The bladder is then minimally dissected off the lower uterine segment to reveal native pubocervical fascia and the course of the uterine vessels. With a combination of blunt and sharp dissection, an adequate surgical window is created medial to each set of uterine vessels at the level of the isthmus (

A 5-mm Mersilene tape is prepared by removing the attached curved needles, and the suture is then introduced into the posterior pelvis through the 10-mm suprapubic port. A 10-mm right-angle forceps through the suprapubic port is used to grasp and position the ligature around the lower uterine segment at the level of the isthmus by first piercing through the surgical windows in an anterior-to-posterior direction to then grasp and withdraw each end of the suture back into the vesicouterine space.

Care must be taken to confirm that the tape is flatly applied to the posterior lower uterine segment. The suture is then tied intracorporeally on the pubocervical fascia with at least five knots (

Whenever possible the vesicouterine peritoneal defect is closed with a running suture and tied extracorporeally. A vaginal exam is then performed to ensure that the suture ligature is above the level of the vaginal fornices. Fetal heart tones are once again documented.

In nongravid patients, a conventional uterine elevator is used for uterine manipulation. Conventional closed laparoscopic techniques are used for peritoneal access. Lower-quadrant trocar sites are lateral to the inferior epigastric vessels and usually at the level of the anterior superior iliac spines.

Whereas I employ the same dissection and suture ligature techniques used during the early cases of interval cerclage, more recently I have employed the classical technique using the two attached 48-mm needles to direct the Mersilene tape through the broad ligament just medial to the uterine vessels at the level of the isthmus.

After dissection of the anterior lower uterine segment to mobilize the bladder and to expose the uterine vessels, the uterus is anteverted and windows are created in the posterior broad ligament to expose the course of the uterine vessels.

The large needles still attached to the tape are introduced into the abdomen through one of the exposed lateral trocar sites by successively grasping each end of the suture several centimeters from the swedge point and then directing the needles through the abdominal wall and then into the peritoneal cavity under direct vision. Using the uterine elevator to retroflex the uterus and then expose the anterior lower uterine segment, I drive each needle medial to the uterine vessels perpendicularly to exit posteriorly as the uterus is simultaneously anteflexed to expose the broad ligament windows (

Once tightened around the lower uterine segment at the level of the isthmus, the tape ends are cut to release the needles, which are then extracted through the open suprapubic port site by reversing the maneuver used for their introduction. Care must be taken to confirm that the tape is flatly applied to the anterior lower uterine segment. The ligature ends are then tied together posteriorly by intracorporeal knot tying and are not peritonealized (

Cervical Cerclage

Cervical cerclage involves the placement of sutures, wires, or synthetic tape to mechanically increase the tensile strength of the cervix. The procedure is done either electively or emergently (rescue) to reduce the risk of cervical insufficiency and the resultant second-trimester recurrent pregnancy loss.

After reviewing the 2006 article in the American Journal of Obstetrics and Gynecology by Dr. Roberto Romero and his associates, the subsequent letter to the editors by Sietske M. Althuisius, Ph.D., and Pieter Hummel, Ph.D., and the author's reply, debate still lingers about whether credit should be given to Lazare Rivière, in his 1655 article published in Latin, for the first description of cervical insufficiency. By 1678, A. Cole, N. Culpepper, and W. Rowland described this entity in their book “Practice of Physick”:“The second fault in women which hindered conception is when the seed is not retained or the orifice of the womb is so slack that it cannot rightly contract itself to keep in the seed; which is chiefly caused by abortion or hard labor and childbirth, whereby the fibers of the womb are broken in pieces one from another and the inner orifice of the womb overmuch slackened.”

Three hundred years later, in an 1865 letter to the editor of the Lancet, G.T. Gream described a patient who had previously undergone cervical surgery “as a cure for dysmenorrhea and sterility.” Gream wrote: “She had arrived at about the fourth month of pregnancy; telling me—without, however, attributing her pregnancy to the operation—that the uterus had 6 years before been operated upon; and so complete had been the division of the cervix that the finger could readily be introduced into the uterine cavity, and the membranes of the ovum could be touched, as they can be sometimes during the last days of gestation. … According to prognostications, abortion resulted but a few weeks afterwards, from the inability of the uterus to retain its contents.”

V.N. Shirodkar, professor of midwifery and gynecology at Grant Medical College in Bombay, India, is credited with the introduction of cervical cerclage into modern obstetric practice in 1955. The need was based on his finding that “some women abort[ed] repeatedly between the fourth and seventh month and no amount of rest and treatment with hormones seemed to help them in retaining the product of conception.” This was immediately followed by Ian McDonald's report from the Royal Melbourne Hospital on his cerclage experience in 70 patients in 1957.

In this edition of Master Class in Gynecologic Surgery, I have asked Dr. Andrew I. Brill, director of minimally invasive gynecology, reparative pelvic surgery, and training at the California Pacific Medical Center, San Francisco, and former president of the AAGL, as well as Dr. Michael Katz, clinical professor of obstetrics, gynecology, and reproductive sciences, University of California, San Francisco, and chief of perinatal services at California Pacific Medical Center, to discuss interval cervicoisthmic cerclage, with an emphasis on a laparoscopic approach.

Dr. Brill coauthored the first report on a laparoscopic preconceptional cervicoisthmic cerclage in a woman with repeated midtrimester cervical cerclage failure for the Journal of Minimally Invasive Gynecology. Despite being an experienced vaginal surgeon and having extensive experience in classical transvaginal cervicoisthmic cerclage, upon observing Dr. Brill's laparoscopic technique, Dr. Katz became familiar with the benefits of this approach. It is our intent that after reading this edition of the Master Class in Gynecologic Surgery, you will, too.

Dr. Brill's Experience

Over the last 5 years, I have performed laparoscopic cervicoisthmic cerclage under general anesthesia in 23 patients who had documented histories consistent with cervical incompetence.

There have been 18 successful deliveries (at a mean gestational age of 36.6 weeks) with a fetal salvage rate of 78% (18/23), compared with 7.3% (6/82) during all of the patients' previous intrauterine pregnancies. In 12 of the 23 cases (52%), the cerclage was performed preconceptionally as an interval procedure. In the remaining 11, cerclage was performed during early pregnancy (at a mean gestational age of 12 weeks). Three of the cases were ultimately completed laparotomically—two secondary to pelvic adhesions and the other secondary to bleeding. In the 11 pregnant patients, only two losses occurred intraoperatively—one secondary to advanced cervical dilation and one for undetermined reasons 10 days postoperatively.

We now know enough about the development and potential complications associated with monochorionic twin pregnancies that the term “twin pregnancy” is no longer precise enough to be used as a medical term. We must distinguish between monochorionic and dichorionic twins.

Monochorionic twin pregnancies have unique features that substantially increase the risk of fetal death, growth restriction, and other complications. The twins share a single placenta, and their circulations are essentially linked to each other through their placental anastomoses. These linked circulations allow blood to be redirected—sometimes very rapidly—toward one twin or the other. This is not typically the case in dichorionic pregnancies.

Thus, we must always take both fetuses in a monochorionic twin pregnancy into consideration, because when one fetus is in jeopardy, the other typically is as well. This interdependency is fundamentally different from the less-entwined relationship of dichorionic twins, and makes monitoring more complicated and all the more important.

We must make the distinction between monochorionic and dichorionic twins early on—optimally, in the first trimester. With the opportunity to make this critical distinction—as well as improvements in fetal therapy and advances in ultrasound assessment that allow us to detect potential problems early—we can lay the foundation for the effective, proactive management of these at-risk pregnancies from the first trimester on.

Once the diagnosis of chorionicity is made, medical reports should specify the type of twin pregnancy that is present, rather than using what should now be considered the layman's term “twin pregnancy.”

The Potential Risks

The potential risks of monochorionic pregnancies stem from:

▸ Unequal placenta sharing. In an ideal world, the twins' single placenta is equally shared. However, it is often the case that one twin will have just 30%–40% of the monochorionic placenta, while the other fetus has the much larger portion. Such unequal placenta sharing leads to an unequal sharing of nutrients, which can lead to growth restriction and severe low birth weight in one of the fetuses.

This type of growth restriction—known as selective intrauterine growth restriction (IUGR)—affects about 10% of all identical twins. It happens quite early in pregnancy and, as we know from singleton growth-restricted fetuses, can lead to a host of troubling complications.

That is why the fetuses in a monochorionic pregnancy can never be treated in isolation. With the early onset of growth restriction in a monochorionic pregnancy, for example, the twin with this complication faces a higher risk of in utero death—an outcome that always negatively impacts the other fetus as well.

In a dichorionic pregnancy, if a co-twin weighs 320 g at 26 weeks and is at high risk of in utero death, we typically would advise the parents to delay delivery. The extremely high likelihood of fetal death of the growth-restricted twin would not justify exposing the otherwise normally grown healthy twin to the risks of prematurity. Accepting the fetal death of the growth-restricted twin and allowing pregnancy to continue gives the larger fetus a very good chance of being healthy at birth rather than being born premature with a significant risk of prematurity-related complications.

However, in a monochorionic pregnancy, intrauterine demise of the smaller fetus could put the healthy co-twin at a significant risk for acute severe hemorrhage into the placenta and circulation of the growth-restricted twin. This carries the risk of brain, renal, and cardiac damage—or even death—of the co-twin. The option of delaying delivery beyond the point of demise of the smaller twin, therefore, is unacceptable in this setting.

Rather, the fetuses would need intensive monitoring by experts who are alert to all the potential signs of fetal deterioration. Additional options, including fetal therapy, might require even more subspecialty evaluation.

▸ Unequal blood volume. Blood volume also may be unequally shared. In uncomplicated pregnancies, blood is exchanged equally through the vascular anastomoses that characterize all monochorionic pregnancies. Sometimes, however, the exchange is unbalanced and blood is shunted in one direction without adequate return.

Anastomoses that are between artery and vein act as one-way valves and can lead to significant differences in volume. Artery-to-artery and vein-to-vein connections allow direct exchange in either direction, with the direction of blood flow determined by the difference in blood pressure on either side.

If one fetus develops an unstable circulation or dies, the instability or resultant drop in blood pressure causes the healthy or surviving twin to lose a large amount of blood volume across the connecting vessels and into the sick or dying twin. This is why, when one fetus dies, the risk of death for the co-twin can be as high as 60%. It also explains why a surviving co-twin has a significant risk of brain injury.

The intertwin anastomoses account for a range of other pregnancy complications. When placenta sharing is equal but there is a significant mismatch in blood flow and blood volume, twin-to-twin syndrome (TTTS) can develop. In this scenario, the imbalance progresses to the extent that one twin becomes a “donor” of blood volume and the other twin becomes the “recipient.”

A decline in blood volume for the donor twin leads to decreased urine output to the extent that bladder filling virtually ceases and oligohydramnios may progress to anhydramnios. The recipient twin, in the meantime, urinates excessively, leading to polyhydramnios and possibly preterm labor.

TTTS develops in about 10%–15% of monochorionic pregnancies. Overall, however—if you add the approximately 10% that are affected by selective IUGR, and an unknown percentage of pregnancies that may have a bit of both problems or are complicated in other ways to this 10%–15%—I estimate that as many as one-third of monochorionic twins have some kind of significant complication.

For TTTS, endoscopic laser ablation (or laser coagulation) of placental anastomoses has been shown to be an effective treatment and a preferable first-line approach for severe cases diagnosed before 26 weeks. These therapies, however, are available only at specialized centers—a fact that adds to the value of early diagnosis of chorionicity and prospective monitoring for complications.

The Need for Early Diagnosis

We cannot attempt to alleviate complications and improve survival unless a diagnosis of monochorionicity is made early. The diagnosis of chorionicity certainly is more difficult in the second trimester.

However, if a patient has not had a first-trimester scan, a diagnosis should still be attempted.

Monochorionic twin pregnancies remain largely unpredictable. At 12 weeks' gestation, however, if we have diagnosed identical twins, there are several ultrasound parameters we can measure to begin to predict how the pregnancy will proceed and what fetal complications might develop.

Some studies have shown, for instance, that a discrepancy in nuchal translucency between the co-twins of more than 60% means that there is a 60%–70% chance that TTTS will develop.

There also may be some discrepancies in size of other structures that are apparent in the first trimester, such as differences in abdominal circumference, for example, as well as differences in amniotic fluid volume, or bladder size that might be helpful in planning fetal surveillance.

After initial evaluation, we generally recommend that monochorionic twins be evaluated again at 16 weeks, based on research by Dr. Liesbeth Lewi of the University Hospitals in Leuven, Belgium, showing that a combined risk assessment in the first trimester and at 16 weeks can predict selective IUGR or TTTS with greater than 80% accuracy.

In a study of 200 monochorionic diamniotic twin pregnancies, Dr. Lewi found that significant predictors of TTTS, selective IUGR, or intrauterine death in the first trimester were crown-rump length and discordant amniotic fluid volume. At 16 weeks, significant predictors were the differences between the co-twins in abdominal circumference, amniotic fluid volume, and the site of cord insertions. [The site of cord insertion was classified as velamentous, eccentric (more than 2 cm from the placental edge), or marginal (less than 2 cm from the placental edge), and a discordant cord insertion was considered to be the combination of a velamentous cord insertion in one fetus and an eccentric cord insertion in the other fetus.]

The differences between the co-twins in the ultrasound parameters were additive when measured in the first trimester and at 16 weeks. Combined risk assessment detected 58% of the fetal complications by classifying 21% of the 200 pregnancies as high risk, with a false-positive rate of 8%, while the predictive value of one assessment alone was significantly lower (Am. J. Obstet. Gynecol. 2008;199:493.e1–7).

Dr. Lewi's research was among the literature considered recently by a panel of experts assembled by the North American Fetal Therapy Network. The panel has been working on a consensus statement that, when finalized, will make recommendations for early diagnosis of monochorionicity and basic combined risk assessment.

Doppler ultrasound (US) measurements of the umbilical arteries, which depict resistance in the blood vessels and resultant blood flow, also may be helpful. Just as with singleton pregnancies, Doppler US provides information in the monochorionic pregnancy about the vasculature of the placenta and the amount of placenta the fetuses have available for nutrient exchange.

In monochorionic pregnancies, however, Doppler US has the added benefit of being key to diagnosing and evaluating hemodynamically significant arterio-arterial anastomoses that induce variations in diastolic velocity not seen in singleton pregnancies.

The imbalance in blood flow exchange between the co-twins' circulations—again, the primary contributor to the development of TTTS—also can be examined using Doppler assessments of two additional vascular beds: the middle cerebral artery (MCA) and the ductus venosus.

The MCA peak systolic velocity reflects how fast blood is flowing in the brain. Large differences in the MCA can point to TTTS. The ductus venosus, a unique fetal vessel that funnels a proportion of nutrient-rich umbilical venous return directly into the right atrium, similarly can be used to evaluate cardiac status. Doppler screening of the ductus venosus and MCA has its most useful role early in pregnancy.

Again, because most of the amniotic fluid from 16 weeks on is due to fetal urination, and because changes in urine output reflect changes in blood volume status, the assessment of bladder filling and amniotic fluid volume reveals much about blood volume status and possible TTTS.

Whenever we see a monochorionic twin pregnancy, therefore, we face a range of questions: What are the sizes of the fetuses? Is there a discrepancy? What is the ultrasound end-diastolic velocity in each twin? Is it normal? Or, is there variability in the waveform, which is indicative of hemodynamically significant arterio-arterial anastomoses? Is the amniotic fluid volume normal? What do the bladders look like? Does one fetus have a bladder that's barely filling?

By regularly asking these questions—and using the pregnancy as its own control—we will be alert to the potential problems associated with monochorionicity and more able to proactively plan our monitoring schedules.

A new discrepancy or a change from a previous exam might mean seeing the patient weekly as opposed to every 2 or 3 weeks.

Frequent monitoring is prudent throughout pregnancy as severe TTTS can develop until 22–23 weeks' gestation, even when findings are normal at 18 weeks.

Moreover, milder forms of TTTS, as well as milder forms of selective IUGR, can develop even later.

Umbilical artery Doppler shows significant variation in end-diastolic velocity from positive/absent to markedly reversed, as well as scalloping of the waveform. This indicates the presence of hemodynamically significant arterio-arterial anastomoses.

At left, the presence of chorionic tissue between the layers of amnion from the two sacs produces a “Lambda” sign (circle) that indicates a dichorionic diamniotic pregnancy. At right, the absence of this sign (arrow) indicates monochorionic placentation.

The fetus on the left has a larger abdominal circumference and a higher maximum vertical amniotic fluid pocket, which can point to unequal placenta sharing and/or unequal blood volume and requires follow-up evaluation. Images courtesy Dr. Ahmet A. Baschat

The Complexity of Multiple Gestation

Multiple gestation is an obstetric condition that confronts every obstetrician at some point. Twin pregnancies, for one, are quite frequent, occurring in 3.2% of all pregnancies. Because of this frequency, it is important that we spend some time reviewing the various presentations of twin pregnancies as well as the potential complications.

Twin pregnancies are not a monolithic condition. As we know, twin pregnancies can present in a two-placenta double-membrane sac (dichorionic diamniotic), in a single-placenta double-membrane sac (monochorionic diamniotic), or in some version thereof.

The clinical presentation of twin pregnancies and the potential complications will vary widely, making it of utmost importance to diagnose chorionicity early on. The simple term “twin pregnancy” is not, as our guest author says, a term that is precise enough, in and of itself, to ensure optimal management. A distinction between monochorionic and dichorionic twins must be made.

The complications that are of greatest concern in monochorionic pregnancies involve the anastomoses between the twins' two vasculatures.

In uncomplicated pregnancies, blood is exchanged equally through these anastomoses.

In some pregnancies, however, blood flow becomes unbalanced to the extent that one or both fetuses are compromised.

The management options for complications such as twin-to-twin transfusion syndrome (TTTS) have traditionally been quite limited.

Until recently, management for TTTS involved observation or the removal of excess amniotic fluid.

More recently, however, surgical interventions have been employed with variable success.

Although every obstetrician may not possess the mastery of fetal surgery in these conditions, it is important that all obstetricians nevertheless understand the options that are available and be able to make accurate diagnoses, offer appropriate counseling, and make referrals if appropriate.

Thus, I believe the focus of this Master Class—monochorionicity, its features, and the facets of good management—will be of significant value to the clinician.

We have invited Dr. Ahmet A. Baschat of the department of obstetrics, gynecology, and reproductive sciences at the University of Maryland, Baltimore, to be our guest professor this month. Dr. Baschat is a recognized national expert in fetal therapy, including various intrauterine surgical procedures.

Key Points

▸ Making an accurate diagnosis of chorionicity early in a twin pregnancy is crucial for the prospective management of potential complications. This is because monochorionic twins have unique features that can lead to unequal placenta sharing and unequal blood volume, increasing the risk of fetal death, growth restriction, and other complications. Early in the first trimester is the optimal time to verify chorionicity.

▸ Estimating fetal growth by measuring head diameter, abdominal circumference, and femur length is an important aspect of assessing placenta sharing and the availability of nutrients. The abdominal circumference is the single best measurement of fetal nutrient status; a discrepancy at 16 weeks increases the risk for subsequent complications.

▸ Evaluating bladder filling in combination with amniotic fluid volume is an important element of estimating fetal blood volume status.

▸ Research shows that a combined risk assessment in the first trimester and at 16 weeks can predict selective intrauterine growth restriction and twin-to-twin transfusion syndrome—two of the major complications of monochorionic pregnancies—with greater than 80% accuracy.

▸ Doppler ultrasound of the umbilical artery is important for assessing placenta sharing and the presence of hemodynamically significant arterio-arterial anastomoses.

We now know enough about the development and potential complications associated with monochorionic twin pregnancies that the term “twin pregnancy” is no longer precise enough to be used as a medical term. We must distinguish between monochorionic and dichorionic twins.

Monochorionic twin pregnancies have unique features that substantially increase the risk of fetal death, growth restriction, and other complications. The twins share a single placenta, and their circulations are essentially linked to each other through their placental anastomoses. These linked circulations allow blood to be redirected—sometimes very rapidly—toward one twin or the other. This is not typically the case in dichorionic pregnancies.

Thus, we must always take both fetuses in a monochorionic twin pregnancy into consideration, because when one fetus is in jeopardy, the other typically is as well. This interdependency is fundamentally different from the less-entwined relationship of dichorionic twins, and makes monitoring more complicated and all the more important.

We must make the distinction between monochorionic and dichorionic twins early on—optimally, in the first trimester. With the opportunity to make this critical distinction—as well as improvements in fetal therapy and advances in ultrasound assessment that allow us to detect potential problems early—we can lay the foundation for the effective, proactive management of these at-risk pregnancies from the first trimester on.

Once the diagnosis of chorionicity is made, medical reports should specify the type of twin pregnancy that is present, rather than using what should now be considered the layman's term “twin pregnancy.”

The Potential Risks

The potential risks of monochorionic pregnancies stem from:

▸ Unequal placenta sharing. In an ideal world, the twins' single placenta is equally shared. However, it is often the case that one twin will have just 30%–40% of the monochorionic placenta, while the other fetus has the much larger portion. Such unequal placenta sharing leads to an unequal sharing of nutrients, which can lead to growth restriction and severe low birth weight in one of the fetuses.

This type of growth restriction—known as selective intrauterine growth restriction (IUGR)—affects about 10% of all identical twins. It happens quite early in pregnancy and, as we know from singleton growth-restricted fetuses, can lead to a host of troubling complications.

That is why the fetuses in a monochorionic pregnancy can never be treated in isolation. With the early onset of growth restriction in a monochorionic pregnancy, for example, the twin with this complication faces a higher risk of in utero death—an outcome that always negatively impacts the other fetus as well.

In a dichorionic pregnancy, if a co-twin weighs 320 g at 26 weeks and is at high risk of in utero death, we typically would advise the parents to delay delivery. The extremely high likelihood of fetal death of the growth-restricted twin would not justify exposing the otherwise normally grown healthy twin to the risks of prematurity. Accepting the fetal death of the growth-restricted twin and allowing pregnancy to continue gives the larger fetus a very good chance of being healthy at birth rather than being born premature with a significant risk of prematurity-related complications.

However, in a monochorionic pregnancy, intrauterine demise of the smaller fetus could put the healthy co-twin at a significant risk for acute severe hemorrhage into the placenta and circulation of the growth-restricted twin. This carries the risk of brain, renal, and cardiac damage—or even death—of the co-twin. The option of delaying delivery beyond the point of demise of the smaller twin, therefore, is unacceptable in this setting.

Rather, the fetuses would need intensive monitoring by experts who are alert to all the potential signs of fetal deterioration. Additional options, including fetal therapy, might require even more subspecialty evaluation.

▸ Unequal blood volume. Blood volume also may be unequally shared. In uncomplicated pregnancies, blood is exchanged equally through the vascular anastomoses that characterize all monochorionic pregnancies. Sometimes, however, the exchange is unbalanced and blood is shunted in one direction without adequate return.

Anastomoses that are between artery and vein act as one-way valves and can lead to significant differences in volume. Artery-to-artery and vein-to-vein connections allow direct exchange in either direction, with the direction of blood flow determined by the difference in blood pressure on either side.

If one fetus develops an unstable circulation or dies, the instability or resultant drop in blood pressure causes the healthy or surviving twin to lose a large amount of blood volume across the connecting vessels and into the sick or dying twin. This is why, when one fetus dies, the risk of death for the co-twin can be as high as 60%. It also explains why a surviving co-twin has a significant risk of brain injury.

The intertwin anastomoses account for a range of other pregnancy complications. When placenta sharing is equal but there is a significant mismatch in blood flow and blood volume, twin-to-twin syndrome (TTTS) can develop. In this scenario, the imbalance progresses to the extent that one twin becomes a “donor” of blood volume and the other twin becomes the “recipient.”

A decline in blood volume for the donor twin leads to decreased urine output to the extent that bladder filling virtually ceases and oligohydramnios may progress to anhydramnios. The recipient twin, in the meantime, urinates excessively, leading to polyhydramnios and possibly preterm labor.

TTTS develops in about 10%–15% of monochorionic pregnancies. Overall, however—if you add the approximately 10% that are affected by selective IUGR, and an unknown percentage of pregnancies that may have a bit of both problems or are complicated in other ways to this 10%–15%—I estimate that as many as one-third of monochorionic twins have some kind of significant complication.

For TTTS, endoscopic laser ablation (or laser coagulation) of placental anastomoses has been shown to be an effective treatment and a preferable first-line approach for severe cases diagnosed before 26 weeks. These therapies, however, are available only at specialized centers—a fact that adds to the value of early diagnosis of chorionicity and prospective monitoring for complications.

The Need for Early Diagnosis

We cannot attempt to alleviate complications and improve survival unless a diagnosis of monochorionicity is made early. The diagnosis of chorionicity certainly is more difficult in the second trimester.

However, if a patient has not had a first-trimester scan, a diagnosis should still be attempted.

Monochorionic twin pregnancies remain largely unpredictable. At 12 weeks' gestation, however, if we have diagnosed identical twins, there are several ultrasound parameters we can measure to begin to predict how the pregnancy will proceed and what fetal complications might develop.

Some studies have shown, for instance, that a discrepancy in nuchal translucency between the co-twins of more than 60% means that there is a 60%–70% chance that TTTS will develop.

There also may be some discrepancies in size of other structures that are apparent in the first trimester, such as differences in abdominal circumference, for example, as well as differences in amniotic fluid volume, or bladder size that might be helpful in planning fetal surveillance.

After initial evaluation, we generally recommend that monochorionic twins be evaluated again at 16 weeks, based on research by Dr. Liesbeth Lewi of the University Hospitals in Leuven, Belgium, showing that a combined risk assessment in the first trimester and at 16 weeks can predict selective IUGR or TTTS with greater than 80% accuracy.

In a study of 200 monochorionic diamniotic twin pregnancies, Dr. Lewi found that significant predictors of TTTS, selective IUGR, or intrauterine death in the first trimester were crown-rump length and discordant amniotic fluid volume. At 16 weeks, significant predictors were the differences between the co-twins in abdominal circumference, amniotic fluid volume, and the site of cord insertions. [The site of cord insertion was classified as velamentous, eccentric (more than 2 cm from the placental edge), or marginal (less than 2 cm from the placental edge), and a discordant cord insertion was considered to be the combination of a velamentous cord insertion in one fetus and an eccentric cord insertion in the other fetus.]

The differences between the co-twins in the ultrasound parameters were additive when measured in the first trimester and at 16 weeks. Combined risk assessment detected 58% of the fetal complications by classifying 21% of the 200 pregnancies as high risk, with a false-positive rate of 8%, while the predictive value of one assessment alone was significantly lower (Am. J. Obstet. Gynecol. 2008;199:493.e1–7).

Dr. Lewi's research was among the literature considered recently by a panel of experts assembled by the North American Fetal Therapy Network. The panel has been working on a consensus statement that, when finalized, will make recommendations for early diagnosis of monochorionicity and basic combined risk assessment.

Doppler ultrasound (US) measurements of the umbilical arteries, which depict resistance in the blood vessels and resultant blood flow, also may be helpful. Just as with singleton pregnancies, Doppler US provides information in the monochorionic pregnancy about the vasculature of the placenta and the amount of placenta the fetuses have available for nutrient exchange.

In monochorionic pregnancies, however, Doppler US has the added benefit of being key to diagnosing and evaluating hemodynamically significant arterio-arterial anastomoses that induce variations in diastolic velocity not seen in singleton pregnancies.

The imbalance in blood flow exchange between the co-twins' circulations—again, the primary contributor to the development of TTTS—also can be examined using Doppler assessments of two additional vascular beds: the middle cerebral artery (MCA) and the ductus venosus.

The MCA peak systolic velocity reflects how fast blood is flowing in the brain. Large differences in the MCA can point to TTTS. The ductus venosus, a unique fetal vessel that funnels a proportion of nutrient-rich umbilical venous return directly into the right atrium, similarly can be used to evaluate cardiac status. Doppler screening of the ductus venosus and MCA has its most useful role early in pregnancy.

Again, because most of the amniotic fluid from 16 weeks on is due to fetal urination, and because changes in urine output reflect changes in blood volume status, the assessment of bladder filling and amniotic fluid volume reveals much about blood volume status and possible TTTS.

Whenever we see a monochorionic twin pregnancy, therefore, we face a range of questions: What are the sizes of the fetuses? Is there a discrepancy? What is the ultrasound end-diastolic velocity in each twin? Is it normal? Or, is there variability in the waveform, which is indicative of hemodynamically significant arterio-arterial anastomoses? Is the amniotic fluid volume normal? What do the bladders look like? Does one fetus have a bladder that's barely filling?

By regularly asking these questions—and using the pregnancy as its own control—we will be alert to the potential problems associated with monochorionicity and more able to proactively plan our monitoring schedules.

A new discrepancy or a change from a previous exam might mean seeing the patient weekly as opposed to every 2 or 3 weeks.

Frequent monitoring is prudent throughout pregnancy as severe TTTS can develop until 22–23 weeks' gestation, even when findings are normal at 18 weeks.

Moreover, milder forms of TTTS, as well as milder forms of selective IUGR, can develop even later.

Umbilical artery Doppler shows significant variation in end-diastolic velocity from positive/absent to markedly reversed, as well as scalloping of the waveform. This indicates the presence of hemodynamically significant arterio-arterial anastomoses.

At left, the presence of chorionic tissue between the layers of amnion from the two sacs produces a “Lambda” sign (circle) that indicates a dichorionic diamniotic pregnancy. At right, the absence of this sign (arrow) indicates monochorionic placentation.

The fetus on the left has a larger abdominal circumference and a higher maximum vertical amniotic fluid pocket, which can point to unequal placenta sharing and/or unequal blood volume and requires follow-up evaluation. Images courtesy Dr. Ahmet A. Baschat

The Complexity of Multiple Gestation

Multiple gestation is an obstetric condition that confronts every obstetrician at some point. Twin pregnancies, for one, are quite frequent, occurring in 3.2% of all pregnancies. Because of this frequency, it is important that we spend some time reviewing the various presentations of twin pregnancies as well as the potential complications.

Twin pregnancies are not a monolithic condition. As we know, twin pregnancies can present in a two-placenta double-membrane sac (dichorionic diamniotic), in a single-placenta double-membrane sac (monochorionic diamniotic), or in some version thereof.

The clinical presentation of twin pregnancies and the potential complications will vary widely, making it of utmost importance to diagnose chorionicity early on. The simple term “twin pregnancy” is not, as our guest author says, a term that is precise enough, in and of itself, to ensure optimal management. A distinction between monochorionic and dichorionic twins must be made.

The complications that are of greatest concern in monochorionic pregnancies involve the anastomoses between the twins' two vasculatures.

In uncomplicated pregnancies, blood is exchanged equally through these anastomoses.

In some pregnancies, however, blood flow becomes unbalanced to the extent that one or both fetuses are compromised.

The management options for complications such as twin-to-twin transfusion syndrome (TTTS) have traditionally been quite limited.

Until recently, management for TTTS involved observation or the removal of excess amniotic fluid.

More recently, however, surgical interventions have been employed with variable success.

Although every obstetrician may not possess the mastery of fetal surgery in these conditions, it is important that all obstetricians nevertheless understand the options that are available and be able to make accurate diagnoses, offer appropriate counseling, and make referrals if appropriate.

Thus, I believe the focus of this Master Class—monochorionicity, its features, and the facets of good management—will be of significant value to the clinician.

We have invited Dr. Ahmet A. Baschat of the department of obstetrics, gynecology, and reproductive sciences at the University of Maryland, Baltimore, to be our guest professor this month. Dr. Baschat is a recognized national expert in fetal therapy, including various intrauterine surgical procedures.

Key Points

▸ Making an accurate diagnosis of chorionicity early in a twin pregnancy is crucial for the prospective management of potential complications. This is because monochorionic twins have unique features that can lead to unequal placenta sharing and unequal blood volume, increasing the risk of fetal death, growth restriction, and other complications. Early in the first trimester is the optimal time to verify chorionicity.

▸ Estimating fetal growth by measuring head diameter, abdominal circumference, and femur length is an important aspect of assessing placenta sharing and the availability of nutrients. The abdominal circumference is the single best measurement of fetal nutrient status; a discrepancy at 16 weeks increases the risk for subsequent complications.

▸ Evaluating bladder filling in combination with amniotic fluid volume is an important element of estimating fetal blood volume status.

▸ Research shows that a combined risk assessment in the first trimester and at 16 weeks can predict selective intrauterine growth restriction and twin-to-twin transfusion syndrome—two of the major complications of monochorionic pregnancies—with greater than 80% accuracy.

▸ Doppler ultrasound of the umbilical artery is important for assessing placenta sharing and the presence of hemodynamically significant arterio-arterial anastomoses.

We now know enough about the development and potential complications associated with monochorionic twin pregnancies that the term “twin pregnancy” is no longer precise enough to be used as a medical term. We must distinguish between monochorionic and dichorionic twins.

Monochorionic twin pregnancies have unique features that substantially increase the risk of fetal death, growth restriction, and other complications. The twins share a single placenta, and their circulations are essentially linked to each other through their placental anastomoses. These linked circulations allow blood to be redirected—sometimes very rapidly—toward one twin or the other. This is not typically the case in dichorionic pregnancies.

Thus, we must always take both fetuses in a monochorionic twin pregnancy into consideration, because when one fetus is in jeopardy, the other typically is as well. This interdependency is fundamentally different from the less-entwined relationship of dichorionic twins, and makes monitoring more complicated and all the more important.

We must make the distinction between monochorionic and dichorionic twins early on—optimally, in the first trimester. With the opportunity to make this critical distinction—as well as improvements in fetal therapy and advances in ultrasound assessment that allow us to detect potential problems early—we can lay the foundation for the effective, proactive management of these at-risk pregnancies from the first trimester on.

Once the diagnosis of chorionicity is made, medical reports should specify the type of twin pregnancy that is present, rather than using what should now be considered the layman's term “twin pregnancy.”

The Potential Risks

The potential risks of monochorionic pregnancies stem from:

▸ Unequal placenta sharing. In an ideal world, the twins' single placenta is equally shared. However, it is often the case that one twin will have just 30%–40% of the monochorionic placenta, while the other fetus has the much larger portion. Such unequal placenta sharing leads to an unequal sharing of nutrients, which can lead to growth restriction and severe low birth weight in one of the fetuses.

This type of growth restriction—known as selective intrauterine growth restriction (IUGR)—affects about 10% of all identical twins. It happens quite early in pregnancy and, as we know from singleton growth-restricted fetuses, can lead to a host of troubling complications.

That is why the fetuses in a monochorionic pregnancy can never be treated in isolation. With the early onset of growth restriction in a monochorionic pregnancy, for example, the twin with this complication faces a higher risk of in utero death—an outcome that always negatively impacts the other fetus as well.

In a dichorionic pregnancy, if a co-twin weighs 320 g at 26 weeks and is at high risk of in utero death, we typically would advise the parents to delay delivery. The extremely high likelihood of fetal death of the growth-restricted twin would not justify exposing the otherwise normally grown healthy twin to the risks of prematurity. Accepting the fetal death of the growth-restricted twin and allowing pregnancy to continue gives the larger fetus a very good chance of being healthy at birth rather than being born premature with a significant risk of prematurity-related complications.

However, in a monochorionic pregnancy, intrauterine demise of the smaller fetus could put the healthy co-twin at a significant risk for acute severe hemorrhage into the placenta and circulation of the growth-restricted twin. This carries the risk of brain, renal, and cardiac damage—or even death—of the co-twin. The option of delaying delivery beyond the point of demise of the smaller twin, therefore, is unacceptable in this setting.

Rather, the fetuses would need intensive monitoring by experts who are alert to all the potential signs of fetal deterioration. Additional options, including fetal therapy, might require even more subspecialty evaluation.

▸ Unequal blood volume. Blood volume also may be unequally shared. In uncomplicated pregnancies, blood is exchanged equally through the vascular anastomoses that characterize all monochorionic pregnancies. Sometimes, however, the exchange is unbalanced and blood is shunted in one direction without adequate return.

Anastomoses that are between artery and vein act as one-way valves and can lead to significant differences in volume. Artery-to-artery and vein-to-vein connections allow direct exchange in either direction, with the direction of blood flow determined by the difference in blood pressure on either side.

If one fetus develops an unstable circulation or dies, the instability or resultant drop in blood pressure causes the healthy or surviving twin to lose a large amount of blood volume across the connecting vessels and into the sick or dying twin. This is why, when one fetus dies, the risk of death for the co-twin can be as high as 60%. It also explains why a surviving co-twin has a significant risk of brain injury.

The intertwin anastomoses account for a range of other pregnancy complications. When placenta sharing is equal but there is a significant mismatch in blood flow and blood volume, twin-to-twin syndrome (TTTS) can develop. In this scenario, the imbalance progresses to the extent that one twin becomes a “donor” of blood volume and the other twin becomes the “recipient.”

A decline in blood volume for the donor twin leads to decreased urine output to the extent that bladder filling virtually ceases and oligohydramnios may progress to anhydramnios. The recipient twin, in the meantime, urinates excessively, leading to polyhydramnios and possibly preterm labor.

TTTS develops in about 10%–15% of monochorionic pregnancies. Overall, however—if you add the approximately 10% that are affected by selective IUGR, and an unknown percentage of pregnancies that may have a bit of both problems or are complicated in other ways to this 10%–15%—I estimate that as many as one-third of monochorionic twins have some kind of significant complication.

For TTTS, endoscopic laser ablation (or laser coagulation) of placental anastomoses has been shown to be an effective treatment and a preferable first-line approach for severe cases diagnosed before 26 weeks. These therapies, however, are available only at specialized centers—a fact that adds to the value of early diagnosis of chorionicity and prospective monitoring for complications.

The Need for Early Diagnosis

We cannot attempt to alleviate complications and improve survival unless a diagnosis of monochorionicity is made early. The diagnosis of chorionicity certainly is more difficult in the second trimester.

However, if a patient has not had a first-trimester scan, a diagnosis should still be attempted.

Monochorionic twin pregnancies remain largely unpredictable. At 12 weeks' gestation, however, if we have diagnosed identical twins, there are several ultrasound parameters we can measure to begin to predict how the pregnancy will proceed and what fetal complications might develop.

Some studies have shown, for instance, that a discrepancy in nuchal translucency between the co-twins of more than 60% means that there is a 60%–70% chance that TTTS will develop.

There also may be some discrepancies in size of other structures that are apparent in the first trimester, such as differences in abdominal circumference, for example, as well as differences in amniotic fluid volume, or bladder size that might be helpful in planning fetal surveillance.

After initial evaluation, we generally recommend that monochorionic twins be evaluated again at 16 weeks, based on research by Dr. Liesbeth Lewi of the University Hospitals in Leuven, Belgium, showing that a combined risk assessment in the first trimester and at 16 weeks can predict selective IUGR or TTTS with greater than 80% accuracy.

In a study of 200 monochorionic diamniotic twin pregnancies, Dr. Lewi found that significant predictors of TTTS, selective IUGR, or intrauterine death in the first trimester were crown-rump length and discordant amniotic fluid volume. At 16 weeks, significant predictors were the differences between the co-twins in abdominal circumference, amniotic fluid volume, and the site of cord insertions. [The site of cord insertion was classified as velamentous, eccentric (more than 2 cm from the placental edge), or marginal (less than 2 cm from the placental edge), and a discordant cord insertion was considered to be the combination of a velamentous cord insertion in one fetus and an eccentric cord insertion in the other fetus.]

The differences between the co-twins in the ultrasound parameters were additive when measured in the first trimester and at 16 weeks. Combined risk assessment detected 58% of the fetal complications by classifying 21% of the 200 pregnancies as high risk, with a false-positive rate of 8%, while the predictive value of one assessment alone was significantly lower (Am. J. Obstet. Gynecol. 2008;199:493.e1–7).

Dr. Lewi's research was among the literature considered recently by a panel of experts assembled by the North American Fetal Therapy Network. The panel has been working on a consensus statement that, when finalized, will make recommendations for early diagnosis of monochorionicity and basic combined risk assessment.

Doppler ultrasound (US) measurements of the umbilical arteries, which depict resistance in the blood vessels and resultant blood flow, also may be helpful. Just as with singleton pregnancies, Doppler US provides information in the monochorionic pregnancy about the vasculature of the placenta and the amount of placenta the fetuses have available for nutrient exchange.

In monochorionic pregnancies, however, Doppler US has the added benefit of being key to diagnosing and evaluating hemodynamically significant arterio-arterial anastomoses that induce variations in diastolic velocity not seen in singleton pregnancies.

The imbalance in blood flow exchange between the co-twins' circulations—again, the primary contributor to the development of TTTS—also can be examined using Doppler assessments of two additional vascular beds: the middle cerebral artery (MCA) and the ductus venosus.

The MCA peak systolic velocity reflects how fast blood is flowing in the brain. Large differences in the MCA can point to TTTS. The ductus venosus, a unique fetal vessel that funnels a proportion of nutrient-rich umbilical venous return directly into the right atrium, similarly can be used to evaluate cardiac status. Doppler screening of the ductus venosus and MCA has its most useful role early in pregnancy.

Again, because most of the amniotic fluid from 16 weeks on is due to fetal urination, and because changes in urine output reflect changes in blood volume status, the assessment of bladder filling and amniotic fluid volume reveals much about blood volume status and possible TTTS.

Whenever we see a monochorionic twin pregnancy, therefore, we face a range of questions: What are the sizes of the fetuses? Is there a discrepancy? What is the ultrasound end-diastolic velocity in each twin? Is it normal? Or, is there variability in the waveform, which is indicative of hemodynamically significant arterio-arterial anastomoses? Is the amniotic fluid volume normal? What do the bladders look like? Does one fetus have a bladder that's barely filling?

By regularly asking these questions—and using the pregnancy as its own control—we will be alert to the potential problems associated with monochorionicity and more able to proactively plan our monitoring schedules.

A new discrepancy or a change from a previous exam might mean seeing the patient weekly as opposed to every 2 or 3 weeks.

Frequent monitoring is prudent throughout pregnancy as severe TTTS can develop until 22–23 weeks' gestation, even when findings are normal at 18 weeks.

Moreover, milder forms of TTTS, as well as milder forms of selective IUGR, can develop even later.

Umbilical artery Doppler shows significant variation in end-diastolic velocity from positive/absent to markedly reversed, as well as scalloping of the waveform. This indicates the presence of hemodynamically significant arterio-arterial anastomoses.

At left, the presence of chorionic tissue between the layers of amnion from the two sacs produces a “Lambda” sign (circle) that indicates a dichorionic diamniotic pregnancy. At right, the absence of this sign (arrow) indicates monochorionic placentation.

The fetus on the left has a larger abdominal circumference and a higher maximum vertical amniotic fluid pocket, which can point to unequal placenta sharing and/or unequal blood volume and requires follow-up evaluation. Images courtesy Dr. Ahmet A. Baschat

The Complexity of Multiple Gestation

Multiple gestation is an obstetric condition that confronts every obstetrician at some point. Twin pregnancies, for one, are quite frequent, occurring in 3.2% of all pregnancies. Because of this frequency, it is important that we spend some time reviewing the various presentations of twin pregnancies as well as the potential complications.

Twin pregnancies are not a monolithic condition. As we know, twin pregnancies can present in a two-placenta double-membrane sac (dichorionic diamniotic), in a single-placenta double-membrane sac (monochorionic diamniotic), or in some version thereof.

The clinical presentation of twin pregnancies and the potential complications will vary widely, making it of utmost importance to diagnose chorionicity early on. The simple term “twin pregnancy” is not, as our guest author says, a term that is precise enough, in and of itself, to ensure optimal management. A distinction between monochorionic and dichorionic twins must be made.

The complications that are of greatest concern in monochorionic pregnancies involve the anastomoses between the twins' two vasculatures.

In uncomplicated pregnancies, blood is exchanged equally through these anastomoses.

In some pregnancies, however, blood flow becomes unbalanced to the extent that one or both fetuses are compromised.

The management options for complications such as twin-to-twin transfusion syndrome (TTTS) have traditionally been quite limited.

Until recently, management for TTTS involved observation or the removal of excess amniotic fluid.

More recently, however, surgical interventions have been employed with variable success.

Although every obstetrician may not possess the mastery of fetal surgery in these conditions, it is important that all obstetricians nevertheless understand the options that are available and be able to make accurate diagnoses, offer appropriate counseling, and make referrals if appropriate.

Thus, I believe the focus of this Master Class—monochorionicity, its features, and the facets of good management—will be of significant value to the clinician.

We have invited Dr. Ahmet A. Baschat of the department of obstetrics, gynecology, and reproductive sciences at the University of Maryland, Baltimore, to be our guest professor this month. Dr. Baschat is a recognized national expert in fetal therapy, including various intrauterine surgical procedures.

Key Points

▸ Making an accurate diagnosis of chorionicity early in a twin pregnancy is crucial for the prospective management of potential complications. This is because monochorionic twins have unique features that can lead to unequal placenta sharing and unequal blood volume, increasing the risk of fetal death, growth restriction, and other complications. Early in the first trimester is the optimal time to verify chorionicity.

▸ Estimating fetal growth by measuring head diameter, abdominal circumference, and femur length is an important aspect of assessing placenta sharing and the availability of nutrients. The abdominal circumference is the single best measurement of fetal nutrient status; a discrepancy at 16 weeks increases the risk for subsequent complications.

▸ Evaluating bladder filling in combination with amniotic fluid volume is an important element of estimating fetal blood volume status.

▸ Research shows that a combined risk assessment in the first trimester and at 16 weeks can predict selective intrauterine growth restriction and twin-to-twin transfusion syndrome—two of the major complications of monochorionic pregnancies—with greater than 80% accuracy.

▸ Doppler ultrasound of the umbilical artery is important for assessing placenta sharing and the presence of hemodynamically significant arterio-arterial anastomoses.

As credited to the Ebers papyrus, prolapse was first described in 1500 B.C. Hippocrates described several methods in the treatment of prolapse, including suspending the patient upside down. Another technique championed by Hippocrates included irrigation of the displaced uterus with wine. Once the uterus was reduced, the position was maintained with a pomegranate “pessary.”

Just after the birth of Christ, Soranus of Ephesus placed perfumes at the patient's head and foul-smelling substances near the prolapsed portion of the uterus to draw the uterus cephalad.

Needless to say, great advancements have occurred since antiquity in the treatment of pelvic organ prolapse.

Most recently, the use of nonabsorbable polypropylene mesh has become increasingly popular. The latest permutation of this technique is the use of a total pelvic floor repair kit.

I have asked Dr. Dennis P. Miller to discuss the use of total pelvic floor repair kits.

Dr. Miller currently serves as the medical director of urogynecology at Wheaton Franciscan Medical Group, Milwaukee. Since 1995, he has proctored hundreds of surgeons in urogynecologic surgery, including laparoscopic and minimally invasive vaginal approaches to incontinence and prolapse.

Currently, Dr. Miller serves on the American Urogynecologic Society Presidential Task Force on graft procedures as well as the International Urogynecologic Association's graft outcomes committee.

Enjoy reading Dr. Miller's excellent article, which is the latest addition in the Master Class in Gynecologic Surgery.

As credited to the Ebers papyrus, prolapse was first described in 1500 B.C. Hippocrates described several methods in the treatment of prolapse, including suspending the patient upside down. Another technique championed by Hippocrates included irrigation of the displaced uterus with wine. Once the uterus was reduced, the position was maintained with a pomegranate “pessary.”

Just after the birth of Christ, Soranus of Ephesus placed perfumes at the patient's head and foul-smelling substances near the prolapsed portion of the uterus to draw the uterus cephalad.

Needless to say, great advancements have occurred since antiquity in the treatment of pelvic organ prolapse.

Most recently, the use of nonabsorbable polypropylene mesh has become increasingly popular. The latest permutation of this technique is the use of a total pelvic floor repair kit.

I have asked Dr. Dennis P. Miller to discuss the use of total pelvic floor repair kits.

Dr. Miller currently serves as the medical director of urogynecology at Wheaton Franciscan Medical Group, Milwaukee. Since 1995, he has proctored hundreds of surgeons in urogynecologic surgery, including laparoscopic and minimally invasive vaginal approaches to incontinence and prolapse.

Currently, Dr. Miller serves on the American Urogynecologic Society Presidential Task Force on graft procedures as well as the International Urogynecologic Association's graft outcomes committee.

Enjoy reading Dr. Miller's excellent article, which is the latest addition in the Master Class in Gynecologic Surgery.

As credited to the Ebers papyrus, prolapse was first described in 1500 B.C. Hippocrates described several methods in the treatment of prolapse, including suspending the patient upside down. Another technique championed by Hippocrates included irrigation of the displaced uterus with wine. Once the uterus was reduced, the position was maintained with a pomegranate “pessary.”

Just after the birth of Christ, Soranus of Ephesus placed perfumes at the patient's head and foul-smelling substances near the prolapsed portion of the uterus to draw the uterus cephalad.

Needless to say, great advancements have occurred since antiquity in the treatment of pelvic organ prolapse.

Most recently, the use of nonabsorbable polypropylene mesh has become increasingly popular. The latest permutation of this technique is the use of a total pelvic floor repair kit.

I have asked Dr. Dennis P. Miller to discuss the use of total pelvic floor repair kits.

Dr. Miller currently serves as the medical director of urogynecology at Wheaton Franciscan Medical Group, Milwaukee. Since 1995, he has proctored hundreds of surgeons in urogynecologic surgery, including laparoscopic and minimally invasive vaginal approaches to incontinence and prolapse.

Currently, Dr. Miller serves on the American Urogynecologic Society Presidential Task Force on graft procedures as well as the International Urogynecologic Association's graft outcomes committee.

Enjoy reading Dr. Miller's excellent article, which is the latest addition in the Master Class in Gynecologic Surgery.

There is a widespread consensus that ultrasound is the clinical standard for the diagnosis of fetal anomalies, and a constellation of factors will ensure its central role into the foreseeable future.

Most importantly, both ultrasound technology and the expertise to perform and interpret it are now widely available. The technology also remains relatively inexpensive, compared with other modalities; its safety has been well established through both study and long-term experience; and it provides real-time visualization, as opposed to images acquired at a particular point in time. Overall, ultrasound should be the first technology employed in the evaluation of the fetal anomaly.

Still, there are well-recognized limitations to sonographic evaluation.

The ability to visualize structures—and thus, the accuracy of a diagnosis—is significantly compromised, for instance, in women who are obese. This is far from a trivial concern today, as the rate of obesity in the United States is high and climbing.

Sonographic evaluation also may be limited by fetal position. Even in an average-size woman, for instance, suboptimal fetal positioning can impair proper visualization of structures.

Another common limitation is the descent of the fetal head into the maternal pelvis. Transvaginal ultrasound is an alternative approach, but the physics of the transvaginal transducer often prevents us from seeing in as many planes as would normally be desirable.

Ultrasound tends to be optimal during midpregnancy. Beyond this point, calcification of the fetal bone structure intensifies. Cranial ossification, for example, can substantially obscure the visualization of intracranial structures.

Finally, effective ultrasound evaluation requires fluid around the fetus. With oligohydramnios, the quality of the sonographic images is significantly compromised.

All told, these limitations are not infrequent or inconsequential. Clinicians commonly encounter such situations during the course of their work.

MRI Technique and Safety

Fetal magnetic resonance imaging provides excellent tissue contrast and is not limited by maternal obesity, skull calcification, or fetal position. It can image the fetus in multiple planes and accomplish this with a large field of view.

MRI can therefore play a valuable role when the findings from ultrasound are unclear or incomplete, or when there is potential for other anomalies that cannot be sufficiently visualized with ultrasound.

MRI relies on the presence of the high water content of tissues, and on the magnetic qualities of the constituent hydrogen nuclei. When tissue is placed in the strong magnetic field of an MRI machine, the hydrogen nuclei or protons move into particular alignments with the applied magnetic field.

Once the protons are lined up, radio frequency pulses are applied, causing the protons to absorb additional energy and spin on their axes of alignment. When the radio frequency pulses are discontinued, the additional energy that the protons had previously absorbed is released. It is this released energy that is transformed into an image. The quantity of energy released will vary depending on the tissue characteristics, such as the relative water and fat content.

Unlike x-ray and CT scans, MRI does not use ionizing radiation. Numerous studies and reports, including studies of MRI technicians who become pregnant, have demonstrated the safety of MRI and the lack of adverse clinical effects. The American College of Radiology published a series of white papers from 1993 to 2004 outlining MRI's safety. Thus, although the safety of MRI continues to be studied, there is no evidence to date that MRI produces harmful effects on human embryos or fetuses.

To be exceedingly cautious, most authorities and practitioners of MRI advise that it not be done in the first trimester.

Even without this extra caution, however, MRI would likely be discouraged in the first trimester because the increased noise-to-signal ratio from imaging such a small structure limits its benefit. It isn't until later in the second trimester, with increased fetal size and fat content, that the quality and resolution of the images achieve a threshold that conveys clinical benefit.

MRI's Leading Indications

MRI is indicated when there is potential for significant change in diagnosis or in patient management beyond the initial ultrasound.

Several studies from both the United States and Europe have demonstrated the clear capability of MRI to significantly modify or alter diagnosis, patient counseling, and management.

In one study of 124 fetuses with central nervous system anomalies detected initially by ultrasound, Dr. Deborah Levine of Harvard Medical School and her colleagues showed that fetal MRI led to 49 major changes in diagnosis and 27 clear changes in management, compared with prior ultrasound.

Suspected central nervous system anomalies—particularly brain anomalies—are, in fact, the most common indication for fetal MRI. There is some literature to support benefits of fetal MRI for other anatomical defects, but the literature provides the strongest evidence of MRI's additional benefit for CNS anomalies. Beyond the CNS, the other two main clinical indications for fetal MRI are for evaluation of the fetal neck and chest.

Among the anomalies and conditions best evaluated by fetal MRI are the following:

▸ Ventriculomegaly. Dilatation of the cerebral ventricles is a relatively common finding by prenatal diagnosticians. Although it is usually well visualized with ultrasound, ventriculomegaly may be accompanied by other associated abnormalities that may remain undetected with sonographic evaluation.

When ventriculomegaly is isolated with no other accompanying anatomical defects, the long-term prognosis is excellent. If there are associated abnormalities, however, the prognosis is significantly compromised, with much worse neurodevelopmental outcomes.

Fetal MRI can help identify those additional abnormalities. Studies from Europe and in the United States have documented significant percentages of cases in which apparently isolated ventriculomegaly was identified on the ultrasound, but was then found to be associated with additional anomalies on the follow-up MRI.

Even in cases with borderline ventricular dilatation, subtle but significant developmental abnormalities are frequently overlooked by ultrasound. MRI diagnosis can facilitate better counseling and prognostication regarding outcome, and can aid in the timely development of management strategies.

▸ Other brain anomalies. MRI can be advantageous for precisely visualizing deep structures of the brain, especially as gestational age advances and the skull becomes calcified. Sometimes, MRI enables visualization of deeper structures—such as the optic chiasma, pituitary stalk, and the pituitary—that are not visible on ultrasound.

Fetal MRI is also advantageous for visualizing subtle lesions of the brain, such as parenchymal infarcts and hemorrhage, and other abnormalities of cortical development. Such subtle anomalies can nevertheless be very consequential to long-term neurologic performance.

In our institution, we order an MRI whenever we see an anomaly of the brain. A persistently and significantly small fetal head with normal-appearing sonographic anatomy may, for example, reveal a lissencephaly syndrome on MRI exam. In patients with a significant family history of brain abnormalities, a confirmatory MRI of the fetal brain, despite a normal sonographic appearance, may be justifiable.

▸ Masses in the neck. MRI is thought to be particularly useful in assessing masses of the fetal neck and the potential for airway obstruction. Limitations of tissue differentiation on ultrasound may preclude a determination of the extent of infiltration of a neck mass. The panoramic view and tissue differentiation of the MRI may overcome this limitation.

These qualities are used to good advantage in determining whether a neck mass is infiltrating or obstructing the fetal airway, and whether it has the potential to prevent spontaneous breathing at delivery. Should such a situation be confirmed prenatally, an EXIT (ex utero intrapartum treatment) procedure can be planned. In this procedure, the fetus's head and shoulders are delivered and the placenta is left attached (maintaining umbilical circulation and fetal oxygenation) while a surgical intubation or tracheoscopy procedure is performed.

▸ Diaphragmatic hernia. Congenital diaphragmatic hernia is among the most common congenital thoracic lesions. Herniation of the abdominal viscus and organs into the chest can lead to compression of the lungs and lung hypoplasia at birth, precluding normal respiration. When the liver is also herniated into the chest, the chances of survival are sharply reduced.

Although possible, it can be difficult to determine herniation of the liver into the chest with ultrasound. MRI easily identifies thoracic displacement of the liver and therefore has prognostic value in congenital diaphragmatic hernia.

Limitations, Future Promise

Prenatal MRI does, however, have limitations. Because the technique is based on contrast between water and fat/lipids, it generally does not provide good quality images before about 24 weeks of gestation—a time period in which neurons, for instance, have not yet undergone significant myelination. Ultrasound, in contrast, tends to be quite effective earlier in pregnancy, which is a distinct advantage.

Availability of MRI technology and specific interest and expertise in fetal MRI also are significantly restricted, compared with ultrasound. Furthermore, MRI technology is significantly more costly than ultrasound at this time.

None of these limitations is immutable. All will likely be addressed or at least attenuated with the passage of time.

Just as important will be the development of a team approach to the use of MRI for fetal anomaly detection. Such an approach would involve embracing the expertise of the obstetrician in fetal anatomy and fetal anomalies in general. The interpretation of fetal MRI images should involve not only radiologists and pediatric subspecialists, such as pediatric neurologists, but also fetal medicine specialists working together.

The greatest promise of fetal MRI lies with further advances in so-called functional MRI. This has the potential to provide information not only about structural features of the anatomy, but about the function of various tissues as well. MRI studies could capitalize, for instance, on the fact that tissue that is injured or developmentally abnormal will have differences in metabolism, compared with normal tissue.

For example, animal studies have shown that the MRI signal of oxygenated hemoglobin is different from the MRI signal of deoxygenated hemoglobin. Utilizing such differences in fetal MRI imaging could enable us to identify oxygen deprivation in fetal and placental tissues.

Advances with MRI spectroscopy, moreover, could provide us with further detailed information on tissue metabolism. Collectively, such advances in MRI could revolutionize research and ultimately clinical assessment of the fetus.

Know the Fetus

The driving force in contemporary times behind the need to evaluate the fetus is the desire of parents to know the most about their fetus as early as possible. Medical indications also may dictate when fetal evaluation is conducted and fetal development assessed.

Prior to the development of ultrasound, such assessment was not possible. However, with the advent of ultrasound technology and other developments that have progressively increased its sophistication, ultrasound imaging has become a reality and an increasingly useful tool. It has been advancing at such a rapid rate that fetal imaging has moved from the third trimester to the second, and even to the first. Not only is fetal growth assessed, but some of the intricacies of fetal development are evaluated as well.

The invasive method of fetal evaluation has taken a similar pathway, expanding from amniocentesis to embryofetoscopy to chorionic-villus sampling to analyte markers in maternal blood. The desire to know more continues to drive the field.

Parents and their physicians call for the greatest possible degree of accuracy and information on the developing fetus.

Fetal MRI technology is an additional tool that is fast evolving in fetal medicine to meet this desire.

At the same time, many have appreciated the limitations of ultrasound technology, which are based upon maternal obesity, fetal position, gestational age, and developmental status of the fetus.

Because of its unique technology, MRI is able to provide added value and new information that was not heretofore possible using current ultrasound technology.

It is in this light that we believe that a Master Class addressing this newest evolving technology is in order.

We have invited Dr. Ray Bahado-Singh, a professor of maternal-fetal medicine at Wayne State University in Detroit and an expert in genetics and prenatal diagnosis, to discuss fetal MRI in detail and to highlight how this new technology may further advance the diagnosis of fetal anomalies.

Key Points

▸ MRI is a rapidly developing technology for fetal diagnosis, and maternal-fetal medicine specialists should develop expertise and collaboration with radiologists.

▸ Substantial clinical and research data demonstrate improvement of CNS diagnoses when MRI is performed after targeted ultrasound.

▸ Emerging data suggest improvement in diagnosis when MRI is used for neck and thoracic abnormalities, excluding the heart.

There is a widespread consensus that ultrasound is the clinical standard for the diagnosis of fetal anomalies, and a constellation of factors will ensure its central role into the foreseeable future.

Most importantly, both ultrasound technology and the expertise to perform and interpret it are now widely available. The technology also remains relatively inexpensive, compared with other modalities; its safety has been well established through both study and long-term experience; and it provides real-time visualization, as opposed to images acquired at a particular point in time. Overall, ultrasound should be the first technology employed in the evaluation of the fetal anomaly.

Still, there are well-recognized limitations to sonographic evaluation.

The ability to visualize structures—and thus, the accuracy of a diagnosis—is significantly compromised, for instance, in women who are obese. This is far from a trivial concern today, as the rate of obesity in the United States is high and climbing.

Sonographic evaluation also may be limited by fetal position. Even in an average-size woman, for instance, suboptimal fetal positioning can impair proper visualization of structures.

Another common limitation is the descent of the fetal head into the maternal pelvis. Transvaginal ultrasound is an alternative approach, but the physics of the transvaginal transducer often prevents us from seeing in as many planes as would normally be desirable.

Ultrasound tends to be optimal during midpregnancy. Beyond this point, calcification of the fetal bone structure intensifies. Cranial ossification, for example, can substantially obscure the visualization of intracranial structures.

Finally, effective ultrasound evaluation requires fluid around the fetus. With oligohydramnios, the quality of the sonographic images is significantly compromised.

All told, these limitations are not infrequent or inconsequential. Clinicians commonly encounter such situations during the course of their work.

MRI Technique and Safety

Fetal magnetic resonance imaging provides excellent tissue contrast and is not limited by maternal obesity, skull calcification, or fetal position. It can image the fetus in multiple planes and accomplish this with a large field of view.

MRI can therefore play a valuable role when the findings from ultrasound are unclear or incomplete, or when there is potential for other anomalies that cannot be sufficiently visualized with ultrasound.

MRI relies on the presence of the high water content of tissues, and on the magnetic qualities of the constituent hydrogen nuclei. When tissue is placed in the strong magnetic field of an MRI machine, the hydrogen nuclei or protons move into particular alignments with the applied magnetic field.

Once the protons are lined up, radio frequency pulses are applied, causing the protons to absorb additional energy and spin on their axes of alignment. When the radio frequency pulses are discontinued, the additional energy that the protons had previously absorbed is released. It is this released energy that is transformed into an image. The quantity of energy released will vary depending on the tissue characteristics, such as the relative water and fat content.

Unlike x-ray and CT scans, MRI does not use ionizing radiation. Numerous studies and reports, including studies of MRI technicians who become pregnant, have demonstrated the safety of MRI and the lack of adverse clinical effects. The American College of Radiology published a series of white papers from 1993 to 2004 outlining MRI's safety. Thus, although the safety of MRI continues to be studied, there is no evidence to date that MRI produces harmful effects on human embryos or fetuses.

To be exceedingly cautious, most authorities and practitioners of MRI advise that it not be done in the first trimester.

Even without this extra caution, however, MRI would likely be discouraged in the first trimester because the increased noise-to-signal ratio from imaging such a small structure limits its benefit. It isn't until later in the second trimester, with increased fetal size and fat content, that the quality and resolution of the images achieve a threshold that conveys clinical benefit.

MRI's Leading Indications

MRI is indicated when there is potential for significant change in diagnosis or in patient management beyond the initial ultrasound.

Several studies from both the United States and Europe have demonstrated the clear capability of MRI to significantly modify or alter diagnosis, patient counseling, and management.

In one study of 124 fetuses with central nervous system anomalies detected initially by ultrasound, Dr. Deborah Levine of Harvard Medical School and her colleagues showed that fetal MRI led to 49 major changes in diagnosis and 27 clear changes in management, compared with prior ultrasound.

Suspected central nervous system anomalies—particularly brain anomalies—are, in fact, the most common indication for fetal MRI. There is some literature to support benefits of fetal MRI for other anatomical defects, but the literature provides the strongest evidence of MRI's additional benefit for CNS anomalies. Beyond the CNS, the other two main clinical indications for fetal MRI are for evaluation of the fetal neck and chest.

Among the anomalies and conditions best evaluated by fetal MRI are the following:

▸ Ventriculomegaly. Dilatation of the cerebral ventricles is a relatively common finding by prenatal diagnosticians. Although it is usually well visualized with ultrasound, ventriculomegaly may be accompanied by other associated abnormalities that may remain undetected with sonographic evaluation.

When ventriculomegaly is isolated with no other accompanying anatomical defects, the long-term prognosis is excellent. If there are associated abnormalities, however, the prognosis is significantly compromised, with much worse neurodevelopmental outcomes.

Fetal MRI can help identify those additional abnormalities. Studies from Europe and in the United States have documented significant percentages of cases in which apparently isolated ventriculomegaly was identified on the ultrasound, but was then found to be associated with additional anomalies on the follow-up MRI.

Even in cases with borderline ventricular dilatation, subtle but significant developmental abnormalities are frequently overlooked by ultrasound. MRI diagnosis can facilitate better counseling and prognostication regarding outcome, and can aid in the timely development of management strategies.

▸ Other brain anomalies. MRI can be advantageous for precisely visualizing deep structures of the brain, especially as gestational age advances and the skull becomes calcified. Sometimes, MRI enables visualization of deeper structures—such as the optic chiasma, pituitary stalk, and the pituitary—that are not visible on ultrasound.

Fetal MRI is also advantageous for visualizing subtle lesions of the brain, such as parenchymal infarcts and hemorrhage, and other abnormalities of cortical development. Such subtle anomalies can nevertheless be very consequential to long-term neurologic performance.

In our institution, we order an MRI whenever we see an anomaly of the brain. A persistently and significantly small fetal head with normal-appearing sonographic anatomy may, for example, reveal a lissencephaly syndrome on MRI exam. In patients with a significant family history of brain abnormalities, a confirmatory MRI of the fetal brain, despite a normal sonographic appearance, may be justifiable.

▸ Masses in the neck. MRI is thought to be particularly useful in assessing masses of the fetal neck and the potential for airway obstruction. Limitations of tissue differentiation on ultrasound may preclude a determination of the extent of infiltration of a neck mass. The panoramic view and tissue differentiation of the MRI may overcome this limitation.

These qualities are used to good advantage in determining whether a neck mass is infiltrating or obstructing the fetal airway, and whether it has the potential to prevent spontaneous breathing at delivery. Should such a situation be confirmed prenatally, an EXIT (ex utero intrapartum treatment) procedure can be planned. In this procedure, the fetus's head and shoulders are delivered and the placenta is left attached (maintaining umbilical circulation and fetal oxygenation) while a surgical intubation or tracheoscopy procedure is performed.

▸ Diaphragmatic hernia. Congenital diaphragmatic hernia is among the most common congenital thoracic lesions. Herniation of the abdominal viscus and organs into the chest can lead to compression of the lungs and lung hypoplasia at birth, precluding normal respiration. When the liver is also herniated into the chest, the chances of survival are sharply reduced.

Although possible, it can be difficult to determine herniation of the liver into the chest with ultrasound. MRI easily identifies thoracic displacement of the liver and therefore has prognostic value in congenital diaphragmatic hernia.

Limitations, Future Promise

Prenatal MRI does, however, have limitations. Because the technique is based on contrast between water and fat/lipids, it generally does not provide good quality images before about 24 weeks of gestation—a time period in which neurons, for instance, have not yet undergone significant myelination. Ultrasound, in contrast, tends to be quite effective earlier in pregnancy, which is a distinct advantage.

Availability of MRI technology and specific interest and expertise in fetal MRI also are significantly restricted, compared with ultrasound. Furthermore, MRI technology is significantly more costly than ultrasound at this time.

None of these limitations is immutable. All will likely be addressed or at least attenuated with the passage of time.

Just as important will be the development of a team approach to the use of MRI for fetal anomaly detection. Such an approach would involve embracing the expertise of the obstetrician in fetal anatomy and fetal anomalies in general. The interpretation of fetal MRI images should involve not only radiologists and pediatric subspecialists, such as pediatric neurologists, but also fetal medicine specialists working together.

The greatest promise of fetal MRI lies with further advances in so-called functional MRI. This has the potential to provide information not only about structural features of the anatomy, but about the function of various tissues as well. MRI studies could capitalize, for instance, on the fact that tissue that is injured or developmentally abnormal will have differences in metabolism, compared with normal tissue.

For example, animal studies have shown that the MRI signal of oxygenated hemoglobin is different from the MRI signal of deoxygenated hemoglobin. Utilizing such differences in fetal MRI imaging could enable us to identify oxygen deprivation in fetal and placental tissues.

Advances with MRI spectroscopy, moreover, could provide us with further detailed information on tissue metabolism. Collectively, such advances in MRI could revolutionize research and ultimately clinical assessment of the fetus.

Know the Fetus

The driving force in contemporary times behind the need to evaluate the fetus is the desire of parents to know the most about their fetus as early as possible. Medical indications also may dictate when fetal evaluation is conducted and fetal development assessed.

Prior to the development of ultrasound, such assessment was not possible. However, with the advent of ultrasound technology and other developments that have progressively increased its sophistication, ultrasound imaging has become a reality and an increasingly useful tool. It has been advancing at such a rapid rate that fetal imaging has moved from the third trimester to the second, and even to the first. Not only is fetal growth assessed, but some of the intricacies of fetal development are evaluated as well.

The invasive method of fetal evaluation has taken a similar pathway, expanding from amniocentesis to embryofetoscopy to chorionic-villus sampling to analyte markers in maternal blood. The desire to know more continues to drive the field.

Parents and their physicians call for the greatest possible degree of accuracy and information on the developing fetus.

Fetal MRI technology is an additional tool that is fast evolving in fetal medicine to meet this desire.

At the same time, many have appreciated the limitations of ultrasound technology, which are based upon maternal obesity, fetal position, gestational age, and developmental status of the fetus.

Because of its unique technology, MRI is able to provide added value and new information that was not heretofore possible using current ultrasound technology.

It is in this light that we believe that a Master Class addressing this newest evolving technology is in order.

We have invited Dr. Ray Bahado-Singh, a professor of maternal-fetal medicine at Wayne State University in Detroit and an expert in genetics and prenatal diagnosis, to discuss fetal MRI in detail and to highlight how this new technology may further advance the diagnosis of fetal anomalies.

Key Points

▸ MRI is a rapidly developing technology for fetal diagnosis, and maternal-fetal medicine specialists should develop expertise and collaboration with radiologists.

▸ Substantial clinical and research data demonstrate improvement of CNS diagnoses when MRI is performed after targeted ultrasound.

▸ Emerging data suggest improvement in diagnosis when MRI is used for neck and thoracic abnormalities, excluding the heart.

There is a widespread consensus that ultrasound is the clinical standard for the diagnosis of fetal anomalies, and a constellation of factors will ensure its central role into the foreseeable future.

Most importantly, both ultrasound technology and the expertise to perform and interpret it are now widely available. The technology also remains relatively inexpensive, compared with other modalities; its safety has been well established through both study and long-term experience; and it provides real-time visualization, as opposed to images acquired at a particular point in time. Overall, ultrasound should be the first technology employed in the evaluation of the fetal anomaly.

Still, there are well-recognized limitations to sonographic evaluation.

The ability to visualize structures—and thus, the accuracy of a diagnosis—is significantly compromised, for instance, in women who are obese. This is far from a trivial concern today, as the rate of obesity in the United States is high and climbing.

Sonographic evaluation also may be limited by fetal position. Even in an average-size woman, for instance, suboptimal fetal positioning can impair proper visualization of structures.

Another common limitation is the descent of the fetal head into the maternal pelvis. Transvaginal ultrasound is an alternative approach, but the physics of the transvaginal transducer often prevents us from seeing in as many planes as would normally be desirable.

Ultrasound tends to be optimal during midpregnancy. Beyond this point, calcification of the fetal bone structure intensifies. Cranial ossification, for example, can substantially obscure the visualization of intracranial structures.

Finally, effective ultrasound evaluation requires fluid around the fetus. With oligohydramnios, the quality of the sonographic images is significantly compromised.

All told, these limitations are not infrequent or inconsequential. Clinicians commonly encounter such situations during the course of their work.

MRI Technique and Safety

Fetal magnetic resonance imaging provides excellent tissue contrast and is not limited by maternal obesity, skull calcification, or fetal position. It can image the fetus in multiple planes and accomplish this with a large field of view.

MRI can therefore play a valuable role when the findings from ultrasound are unclear or incomplete, or when there is potential for other anomalies that cannot be sufficiently visualized with ultrasound.

MRI relies on the presence of the high water content of tissues, and on the magnetic qualities of the constituent hydrogen nuclei. When tissue is placed in the strong magnetic field of an MRI machine, the hydrogen nuclei or protons move into particular alignments with the applied magnetic field.

Once the protons are lined up, radio frequency pulses are applied, causing the protons to absorb additional energy and spin on their axes of alignment. When the radio frequency pulses are discontinued, the additional energy that the protons had previously absorbed is released. It is this released energy that is transformed into an image. The quantity of energy released will vary depending on the tissue characteristics, such as the relative water and fat content.

Unlike x-ray and CT scans, MRI does not use ionizing radiation. Numerous studies and reports, including studies of MRI technicians who become pregnant, have demonstrated the safety of MRI and the lack of adverse clinical effects. The American College of Radiology published a series of white papers from 1993 to 2004 outlining MRI's safety. Thus, although the safety of MRI continues to be studied, there is no evidence to date that MRI produces harmful effects on human embryos or fetuses.

To be exceedingly cautious, most authorities and practitioners of MRI advise that it not be done in the first trimester.

Even without this extra caution, however, MRI would likely be discouraged in the first trimester because the increased noise-to-signal ratio from imaging such a small structure limits its benefit. It isn't until later in the second trimester, with increased fetal size and fat content, that the quality and resolution of the images achieve a threshold that conveys clinical benefit.

MRI's Leading Indications

MRI is indicated when there is potential for significant change in diagnosis or in patient management beyond the initial ultrasound.

Several studies from both the United States and Europe have demonstrated the clear capability of MRI to significantly modify or alter diagnosis, patient counseling, and management.

In one study of 124 fetuses with central nervous system anomalies detected initially by ultrasound, Dr. Deborah Levine of Harvard Medical School and her colleagues showed that fetal MRI led to 49 major changes in diagnosis and 27 clear changes in management, compared with prior ultrasound.

Suspected central nervous system anomalies—particularly brain anomalies—are, in fact, the most common indication for fetal MRI. There is some literature to support benefits of fetal MRI for other anatomical defects, but the literature provides the strongest evidence of MRI's additional benefit for CNS anomalies. Beyond the CNS, the other two main clinical indications for fetal MRI are for evaluation of the fetal neck and chest.

Among the anomalies and conditions best evaluated by fetal MRI are the following:

▸ Ventriculomegaly. Dilatation of the cerebral ventricles is a relatively common finding by prenatal diagnosticians. Although it is usually well visualized with ultrasound, ventriculomegaly may be accompanied by other associated abnormalities that may remain undetected with sonographic evaluation.

When ventriculomegaly is isolated with no other accompanying anatomical defects, the long-term prognosis is excellent. If there are associated abnormalities, however, the prognosis is significantly compromised, with much worse neurodevelopmental outcomes.

Fetal MRI can help identify those additional abnormalities. Studies from Europe and in the United States have documented significant percentages of cases in which apparently isolated ventriculomegaly was identified on the ultrasound, but was then found to be associated with additional anomalies on the follow-up MRI.

Even in cases with borderline ventricular dilatation, subtle but significant developmental abnormalities are frequently overlooked by ultrasound. MRI diagnosis can facilitate better counseling and prognostication regarding outcome, and can aid in the timely development of management strategies.

▸ Other brain anomalies. MRI can be advantageous for precisely visualizing deep structures of the brain, especially as gestational age advances and the skull becomes calcified. Sometimes, MRI enables visualization of deeper structures—such as the optic chiasma, pituitary stalk, and the pituitary—that are not visible on ultrasound.

Fetal MRI is also advantageous for visualizing subtle lesions of the brain, such as parenchymal infarcts and hemorrhage, and other abnormalities of cortical development. Such subtle anomalies can nevertheless be very consequential to long-term neurologic performance.

In our institution, we order an MRI whenever we see an anomaly of the brain. A persistently and significantly small fetal head with normal-appearing sonographic anatomy may, for example, reveal a lissencephaly syndrome on MRI exam. In patients with a significant family history of brain abnormalities, a confirmatory MRI of the fetal brain, despite a normal sonographic appearance, may be justifiable.

▸ Masses in the neck. MRI is thought to be particularly useful in assessing masses of the fetal neck and the potential for airway obstruction. Limitations of tissue differentiation on ultrasound may preclude a determination of the extent of infiltration of a neck mass. The panoramic view and tissue differentiation of the MRI may overcome this limitation.

These qualities are used to good advantage in determining whether a neck mass is infiltrating or obstructing the fetal airway, and whether it has the potential to prevent spontaneous breathing at delivery. Should such a situation be confirmed prenatally, an EXIT (ex utero intrapartum treatment) procedure can be planned. In this procedure, the fetus's head and shoulders are delivered and the placenta is left attached (maintaining umbilical circulation and fetal oxygenation) while a surgical intubation or tracheoscopy procedure is performed.

▸ Diaphragmatic hernia. Congenital diaphragmatic hernia is among the most common congenital thoracic lesions. Herniation of the abdominal viscus and organs into the chest can lead to compression of the lungs and lung hypoplasia at birth, precluding normal respiration. When the liver is also herniated into the chest, the chances of survival are sharply reduced.

Although possible, it can be difficult to determine herniation of the liver into the chest with ultrasound. MRI easily identifies thoracic displacement of the liver and therefore has prognostic value in congenital diaphragmatic hernia.

Limitations, Future Promise

Prenatal MRI does, however, have limitations. Because the technique is based on contrast between water and fat/lipids, it generally does not provide good quality images before about 24 weeks of gestation—a time period in which neurons, for instance, have not yet undergone significant myelination. Ultrasound, in contrast, tends to be quite effective earlier in pregnancy, which is a distinct advantage.

Availability of MRI technology and specific interest and expertise in fetal MRI also are significantly restricted, compared with ultrasound. Furthermore, MRI technology is significantly more costly than ultrasound at this time.

None of these limitations is immutable. All will likely be addressed or at least attenuated with the passage of time.

Just as important will be the development of a team approach to the use of MRI for fetal anomaly detection. Such an approach would involve embracing the expertise of the obstetrician in fetal anatomy and fetal anomalies in general. The interpretation of fetal MRI images should involve not only radiologists and pediatric subspecialists, such as pediatric neurologists, but also fetal medicine specialists working together.

The greatest promise of fetal MRI lies with further advances in so-called functional MRI. This has the potential to provide information not only about structural features of the anatomy, but about the function of various tissues as well. MRI studies could capitalize, for instance, on the fact that tissue that is injured or developmentally abnormal will have differences in metabolism, compared with normal tissue.

For example, animal studies have shown that the MRI signal of oxygenated hemoglobin is different from the MRI signal of deoxygenated hemoglobin. Utilizing such differences in fetal MRI imaging could enable us to identify oxygen deprivation in fetal and placental tissues.

Advances with MRI spectroscopy, moreover, could provide us with further detailed information on tissue metabolism. Collectively, such advances in MRI could revolutionize research and ultimately clinical assessment of the fetus.

Know the Fetus

The driving force in contemporary times behind the need to evaluate the fetus is the desire of parents to know the most about their fetus as early as possible. Medical indications also may dictate when fetal evaluation is conducted and fetal development assessed.

Prior to the development of ultrasound, such assessment was not possible. However, with the advent of ultrasound technology and other developments that have progressively increased its sophistication, ultrasound imaging has become a reality and an increasingly useful tool. It has been advancing at such a rapid rate that fetal imaging has moved from the third trimester to the second, and even to the first. Not only is fetal growth assessed, but some of the intricacies of fetal development are evaluated as well.

The invasive method of fetal evaluation has taken a similar pathway, expanding from amniocentesis to embryofetoscopy to chorionic-villus sampling to analyte markers in maternal blood. The desire to know more continues to drive the field.

Parents and their physicians call for the greatest possible degree of accuracy and information on the developing fetus.

Fetal MRI technology is an additional tool that is fast evolving in fetal medicine to meet this desire.

At the same time, many have appreciated the limitations of ultrasound technology, which are based upon maternal obesity, fetal position, gestational age, and developmental status of the fetus.

Because of its unique technology, MRI is able to provide added value and new information that was not heretofore possible using current ultrasound technology.

It is in this light that we believe that a Master Class addressing this newest evolving technology is in order.

We have invited Dr. Ray Bahado-Singh, a professor of maternal-fetal medicine at Wayne State University in Detroit and an expert in genetics and prenatal diagnosis, to discuss fetal MRI in detail and to highlight how this new technology may further advance the diagnosis of fetal anomalies.

Key Points

▸ MRI is a rapidly developing technology for fetal diagnosis, and maternal-fetal medicine specialists should develop expertise and collaboration with radiologists.

▸ Substantial clinical and research data demonstrate improvement of CNS diagnoses when MRI is performed after targeted ultrasound.

▸ Emerging data suggest improvement in diagnosis when MRI is used for neck and thoracic abnormalities, excluding the heart.

About one of every nine women in the United States will have surgery for a vaginal support defect (pelvic organ prolapse). Our armamentarium of surgical options for helping these patients now includes improved mesh designs and new synthetic mesh kits for transvaginal repair.

The development of synthetic mesh is important, as we have learned over the years that some women have visceral connective tissues (the connective tissues that support the vagina, bladder, and rectum) that are not strong enough to maintain a conventional surgical repair. We have learned, moreover, that surgical repairs utilizing the patient's native tissue too often do not last: Failure rates of 20%–50% have been reported.

Although it's still unclear what constitutes the “perfect mesh,” we have found that the use of a permanent, loosely woven polypropylene mesh can improve our operative results and significantly decrease the failure rates of our reparative vaginal surgery in women with vaginal support defects.

The failure of previous conventional reparative surgery for vaginal support defects is a clear indication for mesh. I operate on many patients who have recurrences of prolapse, and most of the time I use a permanent polypropylene mesh. For almost 4 years, I have been using the transvaginal Prolift systems for anterior, posterior, and total pelvic floor repair; other gynecologic surgeons favor different mesh kits that are currently available.

In October 2008, the Food and Drug Administration issued a Public Health Notification saying that it had received over 1,000 reports from surgical mesh manufacturers of complications associated with mesh devices that are used to repair pelvic organ prolapse and stress urinary incontinence. The warning lists the most frequent complications, such as erosion through vaginal epithelium, infection, pain, and urinary problems. However, the warning does not report which meshes were used—some meshes have been taken off the market—or provide a denominator of the number of total mesh placements.

The warning serves as a reminder of what gynecologic surgeons have advocated thus far: the need for significant experience in reparative vaginal surgery before using mesh implants. It is only in the last 10–15 years that gynecologic surgeons have acquired a detailed understanding of vaginal support anatomy, and of what happens to that anatomy to cause vaginal support defects.

To use mesh kits, the physician must both understand this anatomy and the variability in patients' connective tissues, and have experience in dissection techniques and the safe development of the proper dissection planes between the bladder and vagina, between the rectum and vagina, at the vaginal apex, and in the paravaginal and pararectal areas.

We must be able to dissect without causing undue bleeding or injury, and we must know how to minimize the exposure or erosion of mesh, which is usually through the vaginal wall. (Erosion of the mesh into the bladder or rectum is very rare.) Fortunately, we have access in the postgraduate arena to human cadaver courses that can give us valuable experience.

I have had very few complications in using mesh kits for pelvic floor repair, but I always tell patients that they have a 5% risk of infection, rejection of the mesh, or erosion or exposure of the mesh, as well as a 5%–10% chance of developing dyspareunia. I inform them, of course, that implantation of the mesh is permanent. And I always ask the patient to work with me in diagnosing or resolving any problem, complication, or unexpected outcome if it occurs.

Preparing for the Procedure

I use permanent polypropylene mesh for patients who have a recurring, symptomatic vaginal support defect. Even after the vagina is estrogenized, the vaginal wall in these patients is smooth and lacks the transverse ripples that are indicative, theoretically, of healthy connective tissue that could itself be used for repair.

The Prolift system that I use comprises precut nonabsorbable mesh implants (different precut implants for anterior, posterior, and total repairs) and a set of instruments (anatomical guides and retrieval devices with cannulas) to facilitate mesh placement.

The patient is placed in the dorsal lithotomy position, with her thighs at about 80 degrees to horizontal. She is not overly abducted, and her sacrum is well padded. I recommend using boot-type stirrups. A Foley catheter is inserted.

At 1 hour before anesthesia is administered, I give the patient a dose of prophylactic antibiotic. So far, I have not seen infection from mesh in any of the hundreds of Prolift procedures I've performed.

Anterior Prolapse Repair

The use of anatomical landmarks is critical to the mastery of dissection techniques.

For repair of an anterior vaginal prolapse (a cystocele), the two most important landmarks are the ischial spine and the junction of the inferior pubic ramus with the body of the pubic bone. This is because the “white line” of para-vaginal support goes from one of these points to the other. The anatomical orientation of the anterior vaginal wall must also be delineated. Overlying the lower third is the urethra, and overlying the middle third is the trigone of the bladder, an area of significant innervation. Overlying the upper third of the anterior vaginal wall is the bladder itself. The ureters travel across this upper third from lateral to medial, entering the bladder at the junction of the middle third and the upper third of the vagina.

A 3-cm anterior colpotomy incision is made in the upper third of the vagina. We stay away from the middle of the anterior vaginal wall so that innervation to the bladder is not disrupted, and so that the area underneath the urethra remains fresh for placement of a midurethral transvaginal tape, if needed.

The incision to the anterior vaginal wall should be a full-thickness incision that leaves the white, shiny pubo-cervical fascia on the back of the vaginal epithelium. Once you pass through this fascia, you are in the true vesicovaginal space, and the visceral fascia that surrounds the bladder can be seen.

A curved Mayo scissors, or your finger, can then be used to gently develop the lateral space between the bladder and the vaginal epithelium. There should be minimal bleeding. (If there is more than minimal bleeding, you're either in the wrong dissection plane or you're encountering significant scar tissue from your patient's previous surgery.)

Your goal is to work laterally, so that you can actually feel the tough parietal fascia that covers the obturator muscles.

When you feel the junction of the inferior pubic ramus with the body of the pubic bone—one of the two most important landmarks—you then can slide your finger along the obturator internus fascia right down to the ischial spine. That distance is only about 5–6 cm. By doing so on both sides, the bladder is mobilized away from the anterior vaginal epithelium, and the bladder and ureters are mobilized away from the pelvic side walls. Again, there should be minimal blood loss (no more than 50 cc).

The cannula-equipped curved metal guides must then be passed through the inner thighs. A first incision (no more than 5 mm) is made at the level of the urethra, about 1 cm lateral to the inferior pubic ramus, which you can palpate through the skin of the thigh. This is for the anteromedial, or superficial, passage. The second incision (of the same size) is made at 1 cm lateral and 2 cm posterior to the first mark. This is for the posterolateral, or deep, passage. I always work through the deep passage first. With its tip perpendicular to the skin, I push the cannula-equipped guide straight in until I feel the tip pop through the fascia lata. I then bring the handle of the guide up, so that the directional force is parallel to the fascial white line.

The goal in this deep passage is to pass the guide through the posterior aspect of the obturator membrane and through the obturator internus muscle so that the tip of the cannula is about 1 cm inferior (and a bit anterior) to the ischial spine as it pops through the muscle into the paravaginal space. My finger waits there to feel the tip pass through the fascia of the obturator internus muscle. I then feed a small dull curette into the paravaginal space with my finger and slip it over the cannula, and my assistant carefully removes the guide.

The retrieval device—a piece of long plastic tubing, in essence, with a loop at the end—can then be passed through the cannula. When I feel the loop come through, I entrap it against the end of the curette and pull both the loop and the retrieval device out of the vagina. (Some surgeons hook the loop with a finger, but I find the curette helpful.)

The superficial passage involves the same maneuvers, except this time I'm looking for the junction of the inferior pubic ramus with the body of the pubic bone. With my finger in the paravaginal space, I dissect any intervening tissue away from the fascia of the obturator internus muscle at this junction. I also ensure that the bladder is mobilized away from the central portion of the anterior vaginal epithelium, so that the proximal portion of the mesh—an apical flap—can be attached to the apex of the vagina. (This apical flap also helps repair the anterior enterocele that usually exists with the cystocele.)

When the dissection is complete, I have two cannulas in place on each side, each holding a retrieval device. To attach the mesh, I first place a delayed absorbable suture into the vesicovaginal space through the apex of the vagina, and attach the apical portion of the mesh onto the suture.

I then place each posterolateral, or deep, arm of the mesh by passing about 1 cm of the end of the arm through the loop of the retrieval device, and then pulling the loop back through the cannula. During these maneuvers, we must be sure that no tissue becomes caught in the mesh or the retrieval device loop. The superficial arms of the mesh are then similarly placed.

At this point, I remove the Foley catheter, inject about 300 cc of sterile water into the bladder, and use a 70-degree cystoscope to look through the urethra and into the bladder to confirm the absence of any mesh, perforation, or other injury to the bladder. I also check the functioning of the ureters, and check for any pathology in the bladder. I then empty the bladder and reinsert the Foley catheter before proceeding to finish the mesh placement.

The key to successful mesh placement—and a reduced risk of mesh erosion—lies in placing the mesh loosely in the vesico-vaginal space.

I try to ensure loose placement by lifting up the mesh as I'm removing the cannula so that I can feel the back of the pubic bone. During cannula removal, you can also ensure that the edge of the mesh is at least one finger's breadth away from the pelvic side wall.

Loose placement of the mesh is necessary because the mesh-scar tissue complex that forms will shrink by about 25%–30%. If the mesh is too tight, the risk of erosion and exposure of that mesh to the anterior vaginal wall will rise significantly. It may even appear (if you look into the vagina at the end of the procedure) as if the patient still has a first- or second-degree cystocele. This is fine. Your goal is to have an anterior vaginal wall that is well supported but not straight and tight.

I close the incisions using a running, interlocking Vicryl stitch. I also use vaginal packing for 24 hours, and I send the patient home after the packing and Foley catheter are removed.

The vaginal packing is another key feature of this procedure, as it helps to prevent hematoma formation, which can lead to mesh erosion. It also facilitates the adherence of the mesh to the back of the vaginal epithelium. From my experience, 24 hours is all that is needed.

Most of my patients have reported pain levels of about 3 out of 10, and some are fine with an NSAID. Some are given ketorolac (Toradol) for several days, and others who have more severe pain may be given a conventional narcotic. Patients are seen in the office 2 weeks later and are counseled to call earlier in the case of a high fever, increased vaginal bleeding other than spotting, or significant pain.

Some physicians send patients home with instructions to use vaginal dilators on a daily basis in order to keep the mesh as pliable as possible as it integrates into the scar tissue that forms, but we don't have any studies on the effects of such a recommendation.

Posterior Prolapse Repair

If you are looking at the posterior vaginal wall, the lower third of the vagina overlies the perineal body, and the upper two-thirds overlie the rectum. A full-thickness incision is made either vertically in the middle third of the posterior vaginal wall or transversely through the vaginal epithelium at the junction of the middle-third and lower-third of the vagina.

Using curved Mayo scissors or my finger, I mobilize the rectum away from the vaginal epithelium. I then slide my finger laterally until I feel the iliococcygeus muscle, at which point I gently dissect down until I feel the ischial spine. Any filmy tissue on the sacrospinous ligament should be wiped away medially from the ischial spine at this point.

I also mobilize the rectum away from the underside of the posterior vaginal wall to allow access to the apex of the vagina. Just as with the anterior surgery, all of this dissection should involve minimal blood loss (no more than 50 cc).

The 5-mm incisions for passage of the cannula-equipped guides are made through the skin of the buttocks at 3 cm lateral and 3 cm posterior to the anus. I like to have the patient's back parallel to the floor and to lower the table accordingly so the cannula-equipped guide can be pushed straight in and the tip advanced toward the underside of the sacrospinous ligament.

Again, anatomical landmarks provide significant guidance. As I push the cannula-equipped guide through the ischioanal fossa with one hand, my nondominant finger is on the ischial spine waiting to feel the tip. (If the tip cannot be felt, you can stop and drop the handle of the guide, which will bring the tip up to where it can be felt through the levator ani muscle.)

The goal is to bring the tip of the guide up through the sacrospinous ligament into the dissected rectovaginal space. We want to be sure the tip is at least 2 cm medial to the ischial spine and 1 cm above the lower edge of the sacrospinous ligament. This keeps us far enough away from the pudendal nerve and the internal pudendal artery and vein that travel right underneath the ischial spine along the side wall of the pelvis, and away from the interior gluteal artery nerve and vein that travel near the upper edge of the sacrospinous ligament.

The posterior mesh is positioned by using techniques similar to those of an anterior repair. Again, I find that a dull curette is helpful for capturing the retrieval device.

After the mesh arms are placed, I examine the rectum to make sure there isn't any mesh perforating into the rectum or injury to the rectum. And just as with the anterior repair, the mesh must be placed loosely in the rectovaginal space to minimize erosion.

I often trim a bit of the mesh at the distal end and then place that end in the rectovaginal space to ensure its proximity to the apex of the perineal body. Again, I close the incision with a running interlocking stitch and use vaginal packing for 24 hours. I also often perform a perineorrhaphy to repair the perineal body and help with vaginal support.

When I first started using the Prolift transvaginal mesh kits, my erosion rate (when the mesh could be seen or felt through the vagina) was about 4%. Now, it is about 1%.

The Prolift mesh kit contains loosely woven polypropylene mesh, cannulas, a metal guide, and blue retrieval devices. ©ETHICON, INC.

Vaginal support anatomy: The pubocervical fascia is fused with the anterior vaginal wall and attached to each uterosacral ligament. The bladder passively rests on this “hammock.” ©Elsevier, Clinical Gynecology, Churchill Livingstone 2006

The surgeon's blue-gloved finger is near the right ischial spine; the white cannula traverses the obturator internus muscle. ©ETHICON, INC.

The mesh is placed in the vesicovaginal space and the arms are anchored through the obturator membranes. ©ETHICON, INC.

Synthetic Mesh

In the United States from 2005 to 2007, a reported total of 994,890 surgeries—363,000 procedures for pelvic floor prolapse and 631,890 procedures for stress urinary incontinence—utilized synthetic mesh. The impetus for mesh usage was based on the fact that conventional pelvic floor prolapse repair has an estimated failure rate of 30%–50%.

In October 2008, a Public Health Notification was issued by the Food and Drug Administration regarding complications with the transvaginal placement of surgical mesh for pelvic floor prolapse and stress urinary incontinence. Over a 3-year period, the FDA has received more than 1,000 reports of serious mesh-related complications from nine manufacturers. The most frequent complications included erosion through vaginal epithelium, infection, pain, urinary problems, and recurrence. Additional complications were noted due to bowel, bladder, and blood vessel perforation. In some cases, vaginal scarring and erosion led to decreased quality of life.

Because of the concerns noted above, I believe it is essential to review the proper technique that is involved with synthetic mesh placement for pelvic floor prolapse.

I have asked Dr. Robert M. Rogers to author this Master Class in Gynecologic Surgery. Dr. Rogers currently is in private practice in Kalispell, Mont. Committed to teaching, he serves as the chairman of the education committee of the Society of Gynecologic Surgeons. Not only is Dr. Rogers well known for his surgical prowess, especially in pelvic floor prolapse, but he also has lectured and written extensively on pelvic floor anatomy.

This Master Class will be a lesson not only in pelvic prolapse surgery, but in pelvic anatomy as well.

About one of every nine women in the United States will have surgery for a vaginal support defect (pelvic organ prolapse). Our armamentarium of surgical options for helping these patients now includes improved mesh designs and new synthetic mesh kits for transvaginal repair.

The development of synthetic mesh is important, as we have learned over the years that some women have visceral connective tissues (the connective tissues that support the vagina, bladder, and rectum) that are not strong enough to maintain a conventional surgical repair. We have learned, moreover, that surgical repairs utilizing the patient's native tissue too often do not last: Failure rates of 20%–50% have been reported.

Although it's still unclear what constitutes the “perfect mesh,” we have found that the use of a permanent, loosely woven polypropylene mesh can improve our operative results and significantly decrease the failure rates of our reparative vaginal surgery in women with vaginal support defects.

The failure of previous conventional reparative surgery for vaginal support defects is a clear indication for mesh. I operate on many patients who have recurrences of prolapse, and most of the time I use a permanent polypropylene mesh. For almost 4 years, I have been using the transvaginal Prolift systems for anterior, posterior, and total pelvic floor repair; other gynecologic surgeons favor different mesh kits that are currently available.

In October 2008, the Food and Drug Administration issued a Public Health Notification saying that it had received over 1,000 reports from surgical mesh manufacturers of complications associated with mesh devices that are used to repair pelvic organ prolapse and stress urinary incontinence. The warning lists the most frequent complications, such as erosion through vaginal epithelium, infection, pain, and urinary problems. However, the warning does not report which meshes were used—some meshes have been taken off the market—or provide a denominator of the number of total mesh placements.

The warning serves as a reminder of what gynecologic surgeons have advocated thus far: the need for significant experience in reparative vaginal surgery before using mesh implants. It is only in the last 10–15 years that gynecologic surgeons have acquired a detailed understanding of vaginal support anatomy, and of what happens to that anatomy to cause vaginal support defects.

To use mesh kits, the physician must both understand this anatomy and the variability in patients' connective tissues, and have experience in dissection techniques and the safe development of the proper dissection planes between the bladder and vagina, between the rectum and vagina, at the vaginal apex, and in the paravaginal and pararectal areas.

We must be able to dissect without causing undue bleeding or injury, and we must know how to minimize the exposure or erosion of mesh, which is usually through the vaginal wall. (Erosion of the mesh into the bladder or rectum is very rare.) Fortunately, we have access in the postgraduate arena to human cadaver courses that can give us valuable experience.

I have had very few complications in using mesh kits for pelvic floor repair, but I always tell patients that they have a 5% risk of infection, rejection of the mesh, or erosion or exposure of the mesh, as well as a 5%–10% chance of developing dyspareunia. I inform them, of course, that implantation of the mesh is permanent. And I always ask the patient to work with me in diagnosing or resolving any problem, complication, or unexpected outcome if it occurs.

Preparing for the Procedure

I use permanent polypropylene mesh for patients who have a recurring, symptomatic vaginal support defect. Even after the vagina is estrogenized, the vaginal wall in these patients is smooth and lacks the transverse ripples that are indicative, theoretically, of healthy connective tissue that could itself be used for repair.

The Prolift system that I use comprises precut nonabsorbable mesh implants (different precut implants for anterior, posterior, and total repairs) and a set of instruments (anatomical guides and retrieval devices with cannulas) to facilitate mesh placement.

The patient is placed in the dorsal lithotomy position, with her thighs at about 80 degrees to horizontal. She is not overly abducted, and her sacrum is well padded. I recommend using boot-type stirrups. A Foley catheter is inserted.

At 1 hour before anesthesia is administered, I give the patient a dose of prophylactic antibiotic. So far, I have not seen infection from mesh in any of the hundreds of Prolift procedures I've performed.

Anterior Prolapse Repair

The use of anatomical landmarks is critical to the mastery of dissection techniques.

For repair of an anterior vaginal prolapse (a cystocele), the two most important landmarks are the ischial spine and the junction of the inferior pubic ramus with the body of the pubic bone. This is because the “white line” of para-vaginal support goes from one of these points to the other. The anatomical orientation of the anterior vaginal wall must also be delineated. Overlying the lower third is the urethra, and overlying the middle third is the trigone of the bladder, an area of significant innervation. Overlying the upper third of the anterior vaginal wall is the bladder itself. The ureters travel across this upper third from lateral to medial, entering the bladder at the junction of the middle third and the upper third of the vagina.

A 3-cm anterior colpotomy incision is made in the upper third of the vagina. We stay away from the middle of the anterior vaginal wall so that innervation to the bladder is not disrupted, and so that the area underneath the urethra remains fresh for placement of a midurethral transvaginal tape, if needed.

The incision to the anterior vaginal wall should be a full-thickness incision that leaves the white, shiny pubo-cervical fascia on the back of the vaginal epithelium. Once you pass through this fascia, you are in the true vesicovaginal space, and the visceral fascia that surrounds the bladder can be seen.

A curved Mayo scissors, or your finger, can then be used to gently develop the lateral space between the bladder and the vaginal epithelium. There should be minimal bleeding. (If there is more than minimal bleeding, you're either in the wrong dissection plane or you're encountering significant scar tissue from your patient's previous surgery.)

Your goal is to work laterally, so that you can actually feel the tough parietal fascia that covers the obturator muscles.

When you feel the junction of the inferior pubic ramus with the body of the pubic bone—one of the two most important landmarks—you then can slide your finger along the obturator internus fascia right down to the ischial spine. That distance is only about 5–6 cm. By doing so on both sides, the bladder is mobilized away from the anterior vaginal epithelium, and the bladder and ureters are mobilized away from the pelvic side walls. Again, there should be minimal blood loss (no more than 50 cc).

The cannula-equipped curved metal guides must then be passed through the inner thighs. A first incision (no more than 5 mm) is made at the level of the urethra, about 1 cm lateral to the inferior pubic ramus, which you can palpate through the skin of the thigh. This is for the anteromedial, or superficial, passage. The second incision (of the same size) is made at 1 cm lateral and 2 cm posterior to the first mark. This is for the posterolateral, or deep, passage. I always work through the deep passage first. With its tip perpendicular to the skin, I push the cannula-equipped guide straight in until I feel the tip pop through the fascia lata. I then bring the handle of the guide up, so that the directional force is parallel to the fascial white line.

The goal in this deep passage is to pass the guide through the posterior aspect of the obturator membrane and through the obturator internus muscle so that the tip of the cannula is about 1 cm inferior (and a bit anterior) to the ischial spine as it pops through the muscle into the paravaginal space. My finger waits there to feel the tip pass through the fascia of the obturator internus muscle. I then feed a small dull curette into the paravaginal space with my finger and slip it over the cannula, and my assistant carefully removes the guide.

The retrieval device—a piece of long plastic tubing, in essence, with a loop at the end—can then be passed through the cannula. When I feel the loop come through, I entrap it against the end of the curette and pull both the loop and the retrieval device out of the vagina. (Some surgeons hook the loop with a finger, but I find the curette helpful.)

The superficial passage involves the same maneuvers, except this time I'm looking for the junction of the inferior pubic ramus with the body of the pubic bone. With my finger in the paravaginal space, I dissect any intervening tissue away from the fascia of the obturator internus muscle at this junction. I also ensure that the bladder is mobilized away from the central portion of the anterior vaginal epithelium, so that the proximal portion of the mesh—an apical flap—can be attached to the apex of the vagina. (This apical flap also helps repair the anterior enterocele that usually exists with the cystocele.)

When the dissection is complete, I have two cannulas in place on each side, each holding a retrieval device. To attach the mesh, I first place a delayed absorbable suture into the vesicovaginal space through the apex of the vagina, and attach the apical portion of the mesh onto the suture.

I then place each posterolateral, or deep, arm of the mesh by passing about 1 cm of the end of the arm through the loop of the retrieval device, and then pulling the loop back through the cannula. During these maneuvers, we must be sure that no tissue becomes caught in the mesh or the retrieval device loop. The superficial arms of the mesh are then similarly placed.

At this point, I remove the Foley catheter, inject about 300 cc of sterile water into the bladder, and use a 70-degree cystoscope to look through the urethra and into the bladder to confirm the absence of any mesh, perforation, or other injury to the bladder. I also check the functioning of the ureters, and check for any pathology in the bladder. I then empty the bladder and reinsert the Foley catheter before proceeding to finish the mesh placement.

The key to successful mesh placement—and a reduced risk of mesh erosion—lies in placing the mesh loosely in the vesico-vaginal space.

I try to ensure loose placement by lifting up the mesh as I'm removing the cannula so that I can feel the back of the pubic bone. During cannula removal, you can also ensure that the edge of the mesh is at least one finger's breadth away from the pelvic side wall.

Loose placement of the mesh is necessary because the mesh-scar tissue complex that forms will shrink by about 25%–30%. If the mesh is too tight, the risk of erosion and exposure of that mesh to the anterior vaginal wall will rise significantly. It may even appear (if you look into the vagina at the end of the procedure) as if the patient still has a first- or second-degree cystocele. This is fine. Your goal is to have an anterior vaginal wall that is well supported but not straight and tight.

I close the incisions using a running, interlocking Vicryl stitch. I also use vaginal packing for 24 hours, and I send the patient home after the packing and Foley catheter are removed.

The vaginal packing is another key feature of this procedure, as it helps to prevent hematoma formation, which can lead to mesh erosion. It also facilitates the adherence of the mesh to the back of the vaginal epithelium. From my experience, 24 hours is all that is needed.

Most of my patients have reported pain levels of about 3 out of 10, and some are fine with an NSAID. Some are given ketorolac (Toradol) for several days, and others who have more severe pain may be given a conventional narcotic. Patients are seen in the office 2 weeks later and are counseled to call earlier in the case of a high fever, increased vaginal bleeding other than spotting, or significant pain.

Some physicians send patients home with instructions to use vaginal dilators on a daily basis in order to keep the mesh as pliable as possible as it integrates into the scar tissue that forms, but we don't have any studies on the effects of such a recommendation.

Posterior Prolapse Repair

If you are looking at the posterior vaginal wall, the lower third of the vagina overlies the perineal body, and the upper two-thirds overlie the rectum. A full-thickness incision is made either vertically in the middle third of the posterior vaginal wall or transversely through the vaginal epithelium at the junction of the middle-third and lower-third of the vagina.

Using curved Mayo scissors or my finger, I mobilize the rectum away from the vaginal epithelium. I then slide my finger laterally until I feel the iliococcygeus muscle, at which point I gently dissect down until I feel the ischial spine. Any filmy tissue on the sacrospinous ligament should be wiped away medially from the ischial spine at this point.

I also mobilize the rectum away from the underside of the posterior vaginal wall to allow access to the apex of the vagina. Just as with the anterior surgery, all of this dissection should involve minimal blood loss (no more than 50 cc).

The 5-mm incisions for passage of the cannula-equipped guides are made through the skin of the buttocks at 3 cm lateral and 3 cm posterior to the anus. I like to have the patient's back parallel to the floor and to lower the table accordingly so the cannula-equipped guide can be pushed straight in and the tip advanced toward the underside of the sacrospinous ligament.

Again, anatomical landmarks provide significant guidance. As I push the cannula-equipped guide through the ischioanal fossa with one hand, my nondominant finger is on the ischial spine waiting to feel the tip. (If the tip cannot be felt, you can stop and drop the handle of the guide, which will bring the tip up to where it can be felt through the levator ani muscle.)

The goal is to bring the tip of the guide up through the sacrospinous ligament into the dissected rectovaginal space. We want to be sure the tip is at least 2 cm medial to the ischial spine and 1 cm above the lower edge of the sacrospinous ligament. This keeps us far enough away from the pudendal nerve and the internal pudendal artery and vein that travel right underneath the ischial spine along the side wall of the pelvis, and away from the interior gluteal artery nerve and vein that travel near the upper edge of the sacrospinous ligament.

The posterior mesh is positioned by using techniques similar to those of an anterior repair. Again, I find that a dull curette is helpful for capturing the retrieval device.

After the mesh arms are placed, I examine the rectum to make sure there isn't any mesh perforating into the rectum or injury to the rectum. And just as with the anterior repair, the mesh must be placed loosely in the rectovaginal space to minimize erosion.

I often trim a bit of the mesh at the distal end and then place that end in the rectovaginal space to ensure its proximity to the apex of the perineal body. Again, I close the incision with a running interlocking stitch and use vaginal packing for 24 hours. I also often perform a perineorrhaphy to repair the perineal body and help with vaginal support.

When I first started using the Prolift transvaginal mesh kits, my erosion rate (when the mesh could be seen or felt through the vagina) was about 4%. Now, it is about 1%.

The Prolift mesh kit contains loosely woven polypropylene mesh, cannulas, a metal guide, and blue retrieval devices. ©ETHICON, INC.

Vaginal support anatomy: The pubocervical fascia is fused with the anterior vaginal wall and attached to each uterosacral ligament. The bladder passively rests on this “hammock.” ©Elsevier, Clinical Gynecology, Churchill Livingstone 2006

The surgeon's blue-gloved finger is near the right ischial spine; the white cannula traverses the obturator internus muscle. ©ETHICON, INC.

The mesh is placed in the vesicovaginal space and the arms are anchored through the obturator membranes. ©ETHICON, INC.

Synthetic Mesh

In the United States from 2005 to 2007, a reported total of 994,890 surgeries—363,000 procedures for pelvic floor prolapse and 631,890 procedures for stress urinary incontinence—utilized synthetic mesh. The impetus for mesh usage was based on the fact that conventional pelvic floor prolapse repair has an estimated failure rate of 30%–50%.

In October 2008, a Public Health Notification was issued by the Food and Drug Administration regarding complications with the transvaginal placement of surgical mesh for pelvic floor prolapse and stress urinary incontinence. Over a 3-year period, the FDA has received more than 1,000 reports of serious mesh-related complications from nine manufacturers. The most frequent complications included erosion through vaginal epithelium, infection, pain, urinary problems, and recurrence. Additional complications were noted due to bowel, bladder, and blood vessel perforation. In some cases, vaginal scarring and erosion led to decreased quality of life.

Because of the concerns noted above, I believe it is essential to review the proper technique that is involved with synthetic mesh placement for pelvic floor prolapse.

I have asked Dr. Robert M. Rogers to author this Master Class in Gynecologic Surgery. Dr. Rogers currently is in private practice in Kalispell, Mont. Committed to teaching, he serves as the chairman of the education committee of the Society of Gynecologic Surgeons. Not only is Dr. Rogers well known for his surgical prowess, especially in pelvic floor prolapse, but he also has lectured and written extensively on pelvic floor anatomy.

This Master Class will be a lesson not only in pelvic prolapse surgery, but in pelvic anatomy as well.

About one of every nine women in the United States will have surgery for a vaginal support defect (pelvic organ prolapse). Our armamentarium of surgical options for helping these patients now includes improved mesh designs and new synthetic mesh kits for transvaginal repair.

The development of synthetic mesh is important, as we have learned over the years that some women have visceral connective tissues (the connective tissues that support the vagina, bladder, and rectum) that are not strong enough to maintain a conventional surgical repair. We have learned, moreover, that surgical repairs utilizing the patient's native tissue too often do not last: Failure rates of 20%–50% have been reported.

Although it's still unclear what constitutes the “perfect mesh,” we have found that the use of a permanent, loosely woven polypropylene mesh can improve our operative results and significantly decrease the failure rates of our reparative vaginal surgery in women with vaginal support defects.

The failure of previous conventional reparative surgery for vaginal support defects is a clear indication for mesh. I operate on many patients who have recurrences of prolapse, and most of the time I use a permanent polypropylene mesh. For almost 4 years, I have been using the transvaginal Prolift systems for anterior, posterior, and total pelvic floor repair; other gynecologic surgeons favor different mesh kits that are currently available.

In October 2008, the Food and Drug Administration issued a Public Health Notification saying that it had received over 1,000 reports from surgical mesh manufacturers of complications associated with mesh devices that are used to repair pelvic organ prolapse and stress urinary incontinence. The warning lists the most frequent complications, such as erosion through vaginal epithelium, infection, pain, and urinary problems. However, the warning does not report which meshes were used—some meshes have been taken off the market—or provide a denominator of the number of total mesh placements.

The warning serves as a reminder of what gynecologic surgeons have advocated thus far: the need for significant experience in reparative vaginal surgery before using mesh implants. It is only in the last 10–15 years that gynecologic surgeons have acquired a detailed understanding of vaginal support anatomy, and of what happens to that anatomy to cause vaginal support defects.

To use mesh kits, the physician must both understand this anatomy and the variability in patients' connective tissues, and have experience in dissection techniques and the safe development of the proper dissection planes between the bladder and vagina, between the rectum and vagina, at the vaginal apex, and in the paravaginal and pararectal areas.

We must be able to dissect without causing undue bleeding or injury, and we must know how to minimize the exposure or erosion of mesh, which is usually through the vaginal wall. (Erosion of the mesh into the bladder or rectum is very rare.) Fortunately, we have access in the postgraduate arena to human cadaver courses that can give us valuable experience.

I have had very few complications in using mesh kits for pelvic floor repair, but I always tell patients that they have a 5% risk of infection, rejection of the mesh, or erosion or exposure of the mesh, as well as a 5%–10% chance of developing dyspareunia. I inform them, of course, that implantation of the mesh is permanent. And I always ask the patient to work with me in diagnosing or resolving any problem, complication, or unexpected outcome if it occurs.

Preparing for the Procedure

I use permanent polypropylene mesh for patients who have a recurring, symptomatic vaginal support defect. Even after the vagina is estrogenized, the vaginal wall in these patients is smooth and lacks the transverse ripples that are indicative, theoretically, of healthy connective tissue that could itself be used for repair.

The Prolift system that I use comprises precut nonabsorbable mesh implants (different precut implants for anterior, posterior, and total repairs) and a set of instruments (anatomical guides and retrieval devices with cannulas) to facilitate mesh placement.

The patient is placed in the dorsal lithotomy position, with her thighs at about 80 degrees to horizontal. She is not overly abducted, and her sacrum is well padded. I recommend using boot-type stirrups. A Foley catheter is inserted.

At 1 hour before anesthesia is administered, I give the patient a dose of prophylactic antibiotic. So far, I have not seen infection from mesh in any of the hundreds of Prolift procedures I've performed.

Anterior Prolapse Repair

The use of anatomical landmarks is critical to the mastery of dissection techniques.

For repair of an anterior vaginal prolapse (a cystocele), the two most important landmarks are the ischial spine and the junction of the inferior pubic ramus with the body of the pubic bone. This is because the “white line” of para-vaginal support goes from one of these points to the other. The anatomical orientation of the anterior vaginal wall must also be delineated. Overlying the lower third is the urethra, and overlying the middle third is the trigone of the bladder, an area of significant innervation. Overlying the upper third of the anterior vaginal wall is the bladder itself. The ureters travel across this upper third from lateral to medial, entering the bladder at the junction of the middle third and the upper third of the vagina.

A 3-cm anterior colpotomy incision is made in the upper third of the vagina. We stay away from the middle of the anterior vaginal wall so that innervation to the bladder is not disrupted, and so that the area underneath the urethra remains fresh for placement of a midurethral transvaginal tape, if needed.

The incision to the anterior vaginal wall should be a full-thickness incision that leaves the white, shiny pubo-cervical fascia on the back of the vaginal epithelium. Once you pass through this fascia, you are in the true vesicovaginal space, and the visceral fascia that surrounds the bladder can be seen.

A curved Mayo scissors, or your finger, can then be used to gently develop the lateral space between the bladder and the vaginal epithelium. There should be minimal bleeding. (If there is more than minimal bleeding, you're either in the wrong dissection plane or you're encountering significant scar tissue from your patient's previous surgery.)

Your goal is to work laterally, so that you can actually feel the tough parietal fascia that covers the obturator muscles.

When you feel the junction of the inferior pubic ramus with the body of the pubic bone—one of the two most important landmarks—you then can slide your finger along the obturator internus fascia right down to the ischial spine. That distance is only about 5–6 cm. By doing so on both sides, the bladder is mobilized away from the anterior vaginal epithelium, and the bladder and ureters are mobilized away from the pelvic side walls. Again, there should be minimal blood loss (no more than 50 cc).

The cannula-equipped curved metal guides must then be passed through the inner thighs. A first incision (no more than 5 mm) is made at the level of the urethra, about 1 cm lateral to the inferior pubic ramus, which you can palpate through the skin of the thigh. This is for the anteromedial, or superficial, passage. The second incision (of the same size) is made at 1 cm lateral and 2 cm posterior to the first mark. This is for the posterolateral, or deep, passage. I always work through the deep passage first. With its tip perpendicular to the skin, I push the cannula-equipped guide straight in until I feel the tip pop through the fascia lata. I then bring the handle of the guide up, so that the directional force is parallel to the fascial white line.

The goal in this deep passage is to pass the guide through the posterior aspect of the obturator membrane and through the obturator internus muscle so that the tip of the cannula is about 1 cm inferior (and a bit anterior) to the ischial spine as it pops through the muscle into the paravaginal space. My finger waits there to feel the tip pass through the fascia of the obturator internus muscle. I then feed a small dull curette into the paravaginal space with my finger and slip it over the cannula, and my assistant carefully removes the guide.

The retrieval device—a piece of long plastic tubing, in essence, with a loop at the end—can then be passed through the cannula. When I feel the loop come through, I entrap it against the end of the curette and pull both the loop and the retrieval device out of the vagina. (Some surgeons hook the loop with a finger, but I find the curette helpful.)

The superficial passage involves the same maneuvers, except this time I'm looking for the junction of the inferior pubic ramus with the body of the pubic bone. With my finger in the paravaginal space, I dissect any intervening tissue away from the fascia of the obturator internus muscle at this junction. I also ensure that the bladder is mobilized away from the central portion of the anterior vaginal epithelium, so that the proximal portion of the mesh—an apical flap—can be attached to the apex of the vagina. (This apical flap also helps repair the anterior enterocele that usually exists with the cystocele.)

When the dissection is complete, I have two cannulas in place on each side, each holding a retrieval device. To attach the mesh, I first place a delayed absorbable suture into the vesicovaginal space through the apex of the vagina, and attach the apical portion of the mesh onto the suture.

I then place each posterolateral, or deep, arm of the mesh by passing about 1 cm of the end of the arm through the loop of the retrieval device, and then pulling the loop back through the cannula. During these maneuvers, we must be sure that no tissue becomes caught in the mesh or the retrieval device loop. The superficial arms of the mesh are then similarly placed.

At this point, I remove the Foley catheter, inject about 300 cc of sterile water into the bladder, and use a 70-degree cystoscope to look through the urethra and into the bladder to confirm the absence of any mesh, perforation, or other injury to the bladder. I also check the functioning of the ureters, and check for any pathology in the bladder. I then empty the bladder and reinsert the Foley catheter before proceeding to finish the mesh placement.

The key to successful mesh placement—and a reduced risk of mesh erosion—lies in placing the mesh loosely in the vesico-vaginal space.

I try to ensure loose placement by lifting up the mesh as I'm removing the cannula so that I can feel the back of the pubic bone. During cannula removal, you can also ensure that the edge of the mesh is at least one finger's breadth away from the pelvic side wall.

Loose placement of the mesh is necessary because the mesh-scar tissue complex that forms will shrink by about 25%–30%. If the mesh is too tight, the risk of erosion and exposure of that mesh to the anterior vaginal wall will rise significantly. It may even appear (if you look into the vagina at the end of the procedure) as if the patient still has a first- or second-degree cystocele. This is fine. Your goal is to have an anterior vaginal wall that is well supported but not straight and tight.

I close the incisions using a running, interlocking Vicryl stitch. I also use vaginal packing for 24 hours, and I send the patient home after the packing and Foley catheter are removed.

The vaginal packing is another key feature of this procedure, as it helps to prevent hematoma formation, which can lead to mesh erosion. It also facilitates the adherence of the mesh to the back of the vaginal epithelium. From my experience, 24 hours is all that is needed.

Most of my patients have reported pain levels of about 3 out of 10, and some are fine with an NSAID. Some are given ketorolac (Toradol) for several days, and others who have more severe pain may be given a conventional narcotic. Patients are seen in the office 2 weeks later and are counseled to call earlier in the case of a high fever, increased vaginal bleeding other than spotting, or significant pain.

Some physicians send patients home with instructions to use vaginal dilators on a daily basis in order to keep the mesh as pliable as possible as it integrates into the scar tissue that forms, but we don't have any studies on the effects of such a recommendation.

Posterior Prolapse Repair

If you are looking at the posterior vaginal wall, the lower third of the vagina overlies the perineal body, and the upper two-thirds overlie the rectum. A full-thickness incision is made either vertically in the middle third of the posterior vaginal wall or transversely through the vaginal epithelium at the junction of the middle-third and lower-third of the vagina.

Using curved Mayo scissors or my finger, I mobilize the rectum away from the vaginal epithelium. I then slide my finger laterally until I feel the iliococcygeus muscle, at which point I gently dissect down until I feel the ischial spine. Any filmy tissue on the sacrospinous ligament should be wiped away medially from the ischial spine at this point.

I also mobilize the rectum away from the underside of the posterior vaginal wall to allow access to the apex of the vagina. Just as with the anterior surgery, all of this dissection should involve minimal blood loss (no more than 50 cc).

The 5-mm incisions for passage of the cannula-equipped guides are made through the skin of the buttocks at 3 cm lateral and 3 cm posterior to the anus. I like to have the patient's back parallel to the floor and to lower the table accordingly so the cannula-equipped guide can be pushed straight in and the tip advanced toward the underside of the sacrospinous ligament.

Again, anatomical landmarks provide significant guidance. As I push the cannula-equipped guide through the ischioanal fossa with one hand, my nondominant finger is on the ischial spine waiting to feel the tip. (If the tip cannot be felt, you can stop and drop the handle of the guide, which will bring the tip up to where it can be felt through the levator ani muscle.)

The goal is to bring the tip of the guide up through the sacrospinous ligament into the dissected rectovaginal space. We want to be sure the tip is at least 2 cm medial to the ischial spine and 1 cm above the lower edge of the sacrospinous ligament. This keeps us far enough away from the pudendal nerve and the internal pudendal artery and vein that travel right underneath the ischial spine along the side wall of the pelvis, and away from the interior gluteal artery nerve and vein that travel near the upper edge of the sacrospinous ligament.

The posterior mesh is positioned by using techniques similar to those of an anterior repair. Again, I find that a dull curette is helpful for capturing the retrieval device.

After the mesh arms are placed, I examine the rectum to make sure there isn't any mesh perforating into the rectum or injury to the rectum. And just as with the anterior repair, the mesh must be placed loosely in the rectovaginal space to minimize erosion.

I often trim a bit of the mesh at the distal end and then place that end in the rectovaginal space to ensure its proximity to the apex of the perineal body. Again, I close the incision with a running interlocking stitch and use vaginal packing for 24 hours. I also often perform a perineorrhaphy to repair the perineal body and help with vaginal support.

When I first started using the Prolift transvaginal mesh kits, my erosion rate (when the mesh could be seen or felt through the vagina) was about 4%. Now, it is about 1%.

The Prolift mesh kit contains loosely woven polypropylene mesh, cannulas, a metal guide, and blue retrieval devices. ©ETHICON, INC.

Vaginal support anatomy: The pubocervical fascia is fused with the anterior vaginal wall and attached to each uterosacral ligament. The bladder passively rests on this “hammock.” ©Elsevier, Clinical Gynecology, Churchill Livingstone 2006

The surgeon's blue-gloved finger is near the right ischial spine; the white cannula traverses the obturator internus muscle. ©ETHICON, INC.

The mesh is placed in the vesicovaginal space and the arms are anchored through the obturator membranes. ©ETHICON, INC.

Synthetic Mesh

In the United States from 2005 to 2007, a reported total of 994,890 surgeries—363,000 procedures for pelvic floor prolapse and 631,890 procedures for stress urinary incontinence—utilized synthetic mesh. The impetus for mesh usage was based on the fact that conventional pelvic floor prolapse repair has an estimated failure rate of 30%–50%.

In October 2008, a Public Health Notification was issued by the Food and Drug Administration regarding complications with the transvaginal placement of surgical mesh for pelvic floor prolapse and stress urinary incontinence. Over a 3-year period, the FDA has received more than 1,000 reports of serious mesh-related complications from nine manufacturers. The most frequent complications included erosion through vaginal epithelium, infection, pain, urinary problems, and recurrence. Additional complications were noted due to bowel, bladder, and blood vessel perforation. In some cases, vaginal scarring and erosion led to decreased quality of life.

Because of the concerns noted above, I believe it is essential to review the proper technique that is involved with synthetic mesh placement for pelvic floor prolapse.

I have asked Dr. Robert M. Rogers to author this Master Class in Gynecologic Surgery. Dr. Rogers currently is in private practice in Kalispell, Mont. Committed to teaching, he serves as the chairman of the education committee of the Society of Gynecologic Surgeons. Not only is Dr. Rogers well known for his surgical prowess, especially in pelvic floor prolapse, but he also has lectured and written extensively on pelvic floor anatomy.

This Master Class will be a lesson not only in pelvic prolapse surgery, but in pelvic anatomy as well.

Hospital safety issues have been widely reported and have received significant attention recently. However, solutions have been slow in coming. Thus, the ongoing challenge of creating the safest labor and delivery environments possible has been left with obstetricians. Although the problem is daunting, there are many steps that obstetric and gynecologic practices can take on their own that will reduce adverse events in labor and delivery as well as optimize maternal-fetal outcomes.

Separate reports published almost a decade ago by the Institute of Medicine and the American Hospital Association estimated that 44,000–98,000 patients die each year from errors made during hospital stays.

That higher death rate accounts for almost double the number of people who die in motor vehicle accidents each year in this country, and double the number of women who die annually from breast cancer, according to the Centers for Disease Control and Prevention.

The problem is so severe that Dr. Mark R. Chassin, president of the Joint Commission (an independent, not-for-profit organization that accredits and certifies more than 15,000 health care organizations and programs in the United States), noted recently that the chance of any of us being injured from simply being in a hospital and not as the result of an illness is 40% greater than the likelihood of an airline mishandling our luggage.

The problem of inconsistent and dysfunctional clinical patterns of care in both the inpatient and outpatient settings is even more alarming. One large study involving the review of 18,000 patient charts found that only 55% of patients received care in keeping with current best practices (“Epidemic of Care: A Call for Safer, Better, and More Accountable Health Care.” San Francisco: Jossey-Bass, 2003).

Approximately 5 years ago, the Joint Commission examined all perinatal “sentinel” events across the country in all types of institutions, and found that 72% of such events were linked to breakdowns in communication.

Other identified root causes included staff competency (47%), staff orientation and training (40%), inadequate fetal monitoring (34%), unavailable equipment or drugs (30%), and physician-credentialing issues (30%).

Major issues of concern in the labor and delivery setting involve the fetal heart rate tracing, iatrogenic prematurity, shoulder dystocia, and operative delivery, as well as all the verbal and written communications that are involved with each of these areas.

An American College of Obstetricians and Gynecologists survey noted that the fetal heart tracing accounts for the majority of liability claims pertaining to labor and delivery.

Labor and delivery safety programs should therefore focus primarily on these issues, and on the following:

▸ Simplifying and standardizing protocols for care.

▸ Adopting evidence-based practices.

▸ Relying more on simulation and training.

▸ Working together as a team to accomplish defined goals.

Near-Miss Reporting

The real crux of any patient safety initiative—and the element that goes hand-in-hand with each of these aspects of a program—is a “near-miss” reporting system. This is a concept that medicine borrowed from the airline industry; it involves reporting any occurrence that could have resulted in an adverse event.

A near-miss reporting program is nonpunitive, and empowers everyone involved in the care of a patient to report events and happenings that they believe have the potential to cause problems for patients. Reports are made before injury happens and are reviewed in a blame-free environment. Systems can then be analyzed and modified to minimize recurrence of these events.

In fall 2005, a collaborative effort among the academic faculty at Eastern Virginia Medical School (EVMS) in Norfolk, the obstetric community faculty in that city, and Sentara Healthcare established the OB Right program, with the mission of minimizing iatrogenic injury to the mother and infant and reducing adverse patient safety events at labor and delivery. The “near-miss report form” used by the patient safety program at EVMS and Sentara Healthcare asks for descriptions of events that were “out of the ordinary” or “made you uncomfortable.” It also asks for suggested solutions.

The program has been enormously successful. Over the past 3 years, almost 230 near-misses have been reported by our physicians, residents, and nurses. Echoing the 2004 Joint Commission report, our near-miss reports have shown us that communication issues account for at as many as 60% of these potentially dangerous situations. These reports also have helped solidify a patient safety approach that gives special attention to fetal heart rate monitoring, shoulder dystocia, iatrogenic prematurity, and operative deliveries.

Setting Up a Program

At the time the OB Right program was established, it encompassed two hospitals in the Sentara Healthcare System: Sentara Norfolk General Hospital (the academic tertiary hospital of EVMS) and Sentara Leigh Hospital, (a community hospital in Norfolk that has no 24-hour in-house obstetric coverage). The purpose of including both hospitals was to ensure that the program is successful in both settings.

A steering committee was established immediately to oversee the program, and a clinical nurse specialist was recruited to coordinate program activities and serve as the link between the program and the staff. One of the nurse specialist's first tasks was identifying ways of communicating with physicians and staff, and later, letting them know early on of program successes.

The steering committee included physician leaders from the academic and community obstetric faculty, neonatology and anesthesiology physicians, nurse leaders, hospital administrators, risk managers, and representatives from liability insurance companies.

An education and practice committee was formed to review and recommend educational modules for physicians and staff, to research and develop protocols on best practices, to review practice patterns and recommend changes, to establish a simulation lab, and to implement emergency drills.

A data committee was established to identify retrospective and prospective variables for data collection, as well as data collection methods. Its members were also assigned the jobs of conducting patient and physician satisfaction surveys and of developing a system to collect, report, and debrief faculty and staff on reported near-misses.

Members of the technology committee led an effort to identify and develop technology that would improve patient safety at labor and delivery.

Building the Program

A critical look at all available protocols is a key component of a safety initiative. Simplifying and standardizing the oxytocin order set, for instance, was something we did early on.

It's important to ensure that everyone is speaking the same language. We were particularly struck by the importance of common language and common understanding in fetal heart rate monitoring. For example, early on we surveyed EVMS residents and labor and delivery nurses about how they defined uterine tachysystole. Responses were all over the board, with more than 20 different definitions.

Without a common definition, we realized, we would have not only varying recognition of the problem at labor and delivery, but also poor communication among health team members and the potential for harming the patient.

To prevent errors of mistaking fetal heart rate for maternal heart rate during labor, we adopted the National Institute for Child Health and Human Development's definitions of uterine tachysystole and fetal heart rate patterns. This was an important precursor to the development of protocols for addressing tachysystole and enhancing communication.

We also established universal monitoring of maternal and fetal heart rates. The maternal heart rate is continuously displayed on the fetal heart rate monitor, which substantially reduces the chance for error.

In addition, we studied our cesarean section response time and developed new response time guidelines that enabled us to clearly and efficiently communicate with anesthesiology regarding the various levels of urgency involved. Ultimately, we created four cesarean section categories that provided clear communication among health care teams and allowed for data collection and review. (See box above.)

To significantly reduce unnecessary prematurity and its associated morbidity, we implemented elective induction and cesarean section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

These criteria are currently part of the national voluntary consensus standards for perinatal care in 2008 that were developed by a committee of the National Quality Forum.

Following much debate, we also implemented, at both hospitals, the universal collection of arterial and venous cord pH with every delivery. We have found this practice to be cost effective and to provide objective documentation of fetal intrapartum oxygenation. It also identifies neonates for targeted resuscitation and is a mechanism for continuous quality improvement. Given its potential controversy, however, this practice should not be at the top of the list for safety initiatives at labor and delivery.

Plans in the immediate future include a focus on shoulder dystocia, operative delivery, and triage of patients at labor and delivery.

Given the early success of OB Right, we decided to expand this program to the five other Sentara Healthcare hospitals that provide obstetric services in southeastern Virginia.

In order to achieve this goal, we have created a Clinical Effectiveness Council with physician/nurse team representation from each of the hospitals. The council meets monthly and is currently in the process of implementing key components of the OB Right program.

Keys to Success

We have learned that “buy-in” is key to an effective patient safety initiative. Hospital administration must devote the resources necessary for the success of the program, and both physicians and nurses must be at the table together and be involved as a team with a common safety goal.

A clinical safety coordinator is also essential to the success of a program. This person provides the consistency required and plays a critical role in communicating with the staff in the trenches.

Additionally, it is important to establish methods of communication early on, and to deliver and communicate tangible successes as soon as possible.

The OB Right program communicates with the health care team through posters on labor and delivery, and a newsletter that reports every 3 months on the issues and successes of the program. It also has a Web site with educational modules, near-miss reporting, meeting schedules and minutes, and other interactive tools.

Since OB Right began, we've almost eliminated elective deliveries at less than 39 weeks' gestation, and have achieved an almost-universal compliance with simultaneous maternal and fetal heart rate tracing and measurement of arterial and venous cord pH at both hospitals.

One of the major liability insurance companies sends a representative to the OB Right steering committee meetings and provides premium discounts for physician participation in the OB Right program.

As reported in the Institute of Medicine report “Crossing the Quality Chasm: A New Health System for the 21st Century,” the biggest challenge to moving toward a safer health system is changing the culture from one of blaming individuals for errors to one in which errors are treated not as personal failures but as opportunities to improve the system and prevent harm.

ELSEVIER GLOBAL MEDICAL NEWS

Quality of Care in Obstetrics

Patient safety has become an emphasized area of medicine in recent years. This is not to suggest that the issue of patient safety is new to medicine. Historically, it has been assumed to be a natural part of good medicine and the provision of good medical care.

In 1999, the Institute of Medicine released shocking statistics, estimating that as many as 98,000 people die in any given year as a result of medical errors that occur in hospitals. In the now well-cited report “To Err Is Human: Building a Safer Health Care System,” the IOM asserted that errors occur because good physicians and health care providers work within a bad system. It set a minimum goal of reducing errors by 50% over the next 5 years, and laid out a national agenda for improving patient safety.

This report was followed up by another IOM report published in 2001, “Crossing the Quality Chasm: A New Health Care System for the 21st Century.” This report further defined what kind of change is needed to “close the quality gap.” It provided overarching principles for clinicians, among others, and looked at how systems approaches can be used to implement change.

With both reports—two of many IOM studies and publications aimed at improving the nation's quality of care—a light has been shown nationally and internationally on the importance of not simply assuming that good quality care is part of medicine but, instead, emphasizing and critically analyzing the state of affairs relative to patient safety and quality of care.

Most of our institutions by now have implemented major organizational and structural changes aimed specifically at introducing safety and quality measures. These changes and structures—and the ensuing outcomes—must be monitored so that deviations from the currently available national best practices and standards of care can be identified and corrected.

In obstetrics in particular, where the litigious environment is so challenging, patient safety initiatives become even more important. For this reason, we believe that a Master Class highlighting a particular safety and quality of care initiative in obstetrics may both provide guidance and serve as a catalyst for other centers to emulate.

We have invited Dr. Alfred Z. Abuhamad to be our guest professor. Dr. Abuhamad serves as chairman of the department of ob.gyn. at the Eastern Virginia Medical School, Norfolk, and is the Mason C. Andrews Professor of Obstetrics and Gynecology there. He has played a key role in establishing a patient safety initiative in labor and delivery at EVMS and Sentara Healthcare, and will share, in detail, what he and his colleagues have learned in implementing this initiative.

Key Points About Patient Safety

▸ An estimated 44,000–98,000 patients die each year from errors made during hospital stays.

▸ Two-thirds of perinatal sentinel events are primarily linked to communication issues.

▸ Experience with the OB Right patient safety initiative at Eastern Virginia Medical School and Sentara Healthcare has demonstrated the importance of common language and common understanding when it comes to fetal heart rate monitoring.

▸ To significantly diminish unnecessary prematurity and its associated morbidity, patient safety initiatives should include elective induction and C-section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

Hospital safety issues have been widely reported and have received significant attention recently. However, solutions have been slow in coming. Thus, the ongoing challenge of creating the safest labor and delivery environments possible has been left with obstetricians. Although the problem is daunting, there are many steps that obstetric and gynecologic practices can take on their own that will reduce adverse events in labor and delivery as well as optimize maternal-fetal outcomes.

Separate reports published almost a decade ago by the Institute of Medicine and the American Hospital Association estimated that 44,000–98,000 patients die each year from errors made during hospital stays.

That higher death rate accounts for almost double the number of people who die in motor vehicle accidents each year in this country, and double the number of women who die annually from breast cancer, according to the Centers for Disease Control and Prevention.

The problem is so severe that Dr. Mark R. Chassin, president of the Joint Commission (an independent, not-for-profit organization that accredits and certifies more than 15,000 health care organizations and programs in the United States), noted recently that the chance of any of us being injured from simply being in a hospital and not as the result of an illness is 40% greater than the likelihood of an airline mishandling our luggage.

The problem of inconsistent and dysfunctional clinical patterns of care in both the inpatient and outpatient settings is even more alarming. One large study involving the review of 18,000 patient charts found that only 55% of patients received care in keeping with current best practices (“Epidemic of Care: A Call for Safer, Better, and More Accountable Health Care.” San Francisco: Jossey-Bass, 2003).

Approximately 5 years ago, the Joint Commission examined all perinatal “sentinel” events across the country in all types of institutions, and found that 72% of such events were linked to breakdowns in communication.

Other identified root causes included staff competency (47%), staff orientation and training (40%), inadequate fetal monitoring (34%), unavailable equipment or drugs (30%), and physician-credentialing issues (30%).

Major issues of concern in the labor and delivery setting involve the fetal heart rate tracing, iatrogenic prematurity, shoulder dystocia, and operative delivery, as well as all the verbal and written communications that are involved with each of these areas.

An American College of Obstetricians and Gynecologists survey noted that the fetal heart tracing accounts for the majority of liability claims pertaining to labor and delivery.

Labor and delivery safety programs should therefore focus primarily on these issues, and on the following:

▸ Simplifying and standardizing protocols for care.

▸ Adopting evidence-based practices.

▸ Relying more on simulation and training.

▸ Working together as a team to accomplish defined goals.

Near-Miss Reporting

The real crux of any patient safety initiative—and the element that goes hand-in-hand with each of these aspects of a program—is a “near-miss” reporting system. This is a concept that medicine borrowed from the airline industry; it involves reporting any occurrence that could have resulted in an adverse event.

A near-miss reporting program is nonpunitive, and empowers everyone involved in the care of a patient to report events and happenings that they believe have the potential to cause problems for patients. Reports are made before injury happens and are reviewed in a blame-free environment. Systems can then be analyzed and modified to minimize recurrence of these events.

In fall 2005, a collaborative effort among the academic faculty at Eastern Virginia Medical School (EVMS) in Norfolk, the obstetric community faculty in that city, and Sentara Healthcare established the OB Right program, with the mission of minimizing iatrogenic injury to the mother and infant and reducing adverse patient safety events at labor and delivery. The “near-miss report form” used by the patient safety program at EVMS and Sentara Healthcare asks for descriptions of events that were “out of the ordinary” or “made you uncomfortable.” It also asks for suggested solutions.

The program has been enormously successful. Over the past 3 years, almost 230 near-misses have been reported by our physicians, residents, and nurses. Echoing the 2004 Joint Commission report, our near-miss reports have shown us that communication issues account for at as many as 60% of these potentially dangerous situations. These reports also have helped solidify a patient safety approach that gives special attention to fetal heart rate monitoring, shoulder dystocia, iatrogenic prematurity, and operative deliveries.

Setting Up a Program

At the time the OB Right program was established, it encompassed two hospitals in the Sentara Healthcare System: Sentara Norfolk General Hospital (the academic tertiary hospital of EVMS) and Sentara Leigh Hospital, (a community hospital in Norfolk that has no 24-hour in-house obstetric coverage). The purpose of including both hospitals was to ensure that the program is successful in both settings.

A steering committee was established immediately to oversee the program, and a clinical nurse specialist was recruited to coordinate program activities and serve as the link between the program and the staff. One of the nurse specialist's first tasks was identifying ways of communicating with physicians and staff, and later, letting them know early on of program successes.

The steering committee included physician leaders from the academic and community obstetric faculty, neonatology and anesthesiology physicians, nurse leaders, hospital administrators, risk managers, and representatives from liability insurance companies.

An education and practice committee was formed to review and recommend educational modules for physicians and staff, to research and develop protocols on best practices, to review practice patterns and recommend changes, to establish a simulation lab, and to implement emergency drills.

A data committee was established to identify retrospective and prospective variables for data collection, as well as data collection methods. Its members were also assigned the jobs of conducting patient and physician satisfaction surveys and of developing a system to collect, report, and debrief faculty and staff on reported near-misses.

Members of the technology committee led an effort to identify and develop technology that would improve patient safety at labor and delivery.

Building the Program

A critical look at all available protocols is a key component of a safety initiative. Simplifying and standardizing the oxytocin order set, for instance, was something we did early on.

It's important to ensure that everyone is speaking the same language. We were particularly struck by the importance of common language and common understanding in fetal heart rate monitoring. For example, early on we surveyed EVMS residents and labor and delivery nurses about how they defined uterine tachysystole. Responses were all over the board, with more than 20 different definitions.

Without a common definition, we realized, we would have not only varying recognition of the problem at labor and delivery, but also poor communication among health team members and the potential for harming the patient.

To prevent errors of mistaking fetal heart rate for maternal heart rate during labor, we adopted the National Institute for Child Health and Human Development's definitions of uterine tachysystole and fetal heart rate patterns. This was an important precursor to the development of protocols for addressing tachysystole and enhancing communication.

We also established universal monitoring of maternal and fetal heart rates. The maternal heart rate is continuously displayed on the fetal heart rate monitor, which substantially reduces the chance for error.

In addition, we studied our cesarean section response time and developed new response time guidelines that enabled us to clearly and efficiently communicate with anesthesiology regarding the various levels of urgency involved. Ultimately, we created four cesarean section categories that provided clear communication among health care teams and allowed for data collection and review. (See box above.)

To significantly reduce unnecessary prematurity and its associated morbidity, we implemented elective induction and cesarean section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

These criteria are currently part of the national voluntary consensus standards for perinatal care in 2008 that were developed by a committee of the National Quality Forum.

Following much debate, we also implemented, at both hospitals, the universal collection of arterial and venous cord pH with every delivery. We have found this practice to be cost effective and to provide objective documentation of fetal intrapartum oxygenation. It also identifies neonates for targeted resuscitation and is a mechanism for continuous quality improvement. Given its potential controversy, however, this practice should not be at the top of the list for safety initiatives at labor and delivery.

Plans in the immediate future include a focus on shoulder dystocia, operative delivery, and triage of patients at labor and delivery.

Given the early success of OB Right, we decided to expand this program to the five other Sentara Healthcare hospitals that provide obstetric services in southeastern Virginia.

In order to achieve this goal, we have created a Clinical Effectiveness Council with physician/nurse team representation from each of the hospitals. The council meets monthly and is currently in the process of implementing key components of the OB Right program.

Keys to Success

We have learned that “buy-in” is key to an effective patient safety initiative. Hospital administration must devote the resources necessary for the success of the program, and both physicians and nurses must be at the table together and be involved as a team with a common safety goal.

A clinical safety coordinator is also essential to the success of a program. This person provides the consistency required and plays a critical role in communicating with the staff in the trenches.

Additionally, it is important to establish methods of communication early on, and to deliver and communicate tangible successes as soon as possible.

The OB Right program communicates with the health care team through posters on labor and delivery, and a newsletter that reports every 3 months on the issues and successes of the program. It also has a Web site with educational modules, near-miss reporting, meeting schedules and minutes, and other interactive tools.

Since OB Right began, we've almost eliminated elective deliveries at less than 39 weeks' gestation, and have achieved an almost-universal compliance with simultaneous maternal and fetal heart rate tracing and measurement of arterial and venous cord pH at both hospitals.

One of the major liability insurance companies sends a representative to the OB Right steering committee meetings and provides premium discounts for physician participation in the OB Right program.

As reported in the Institute of Medicine report “Crossing the Quality Chasm: A New Health System for the 21st Century,” the biggest challenge to moving toward a safer health system is changing the culture from one of blaming individuals for errors to one in which errors are treated not as personal failures but as opportunities to improve the system and prevent harm.

ELSEVIER GLOBAL MEDICAL NEWS

Quality of Care in Obstetrics

Patient safety has become an emphasized area of medicine in recent years. This is not to suggest that the issue of patient safety is new to medicine. Historically, it has been assumed to be a natural part of good medicine and the provision of good medical care.

In 1999, the Institute of Medicine released shocking statistics, estimating that as many as 98,000 people die in any given year as a result of medical errors that occur in hospitals. In the now well-cited report “To Err Is Human: Building a Safer Health Care System,” the IOM asserted that errors occur because good physicians and health care providers work within a bad system. It set a minimum goal of reducing errors by 50% over the next 5 years, and laid out a national agenda for improving patient safety.

This report was followed up by another IOM report published in 2001, “Crossing the Quality Chasm: A New Health Care System for the 21st Century.” This report further defined what kind of change is needed to “close the quality gap.” It provided overarching principles for clinicians, among others, and looked at how systems approaches can be used to implement change.

With both reports—two of many IOM studies and publications aimed at improving the nation's quality of care—a light has been shown nationally and internationally on the importance of not simply assuming that good quality care is part of medicine but, instead, emphasizing and critically analyzing the state of affairs relative to patient safety and quality of care.

Most of our institutions by now have implemented major organizational and structural changes aimed specifically at introducing safety and quality measures. These changes and structures—and the ensuing outcomes—must be monitored so that deviations from the currently available national best practices and standards of care can be identified and corrected.

In obstetrics in particular, where the litigious environment is so challenging, patient safety initiatives become even more important. For this reason, we believe that a Master Class highlighting a particular safety and quality of care initiative in obstetrics may both provide guidance and serve as a catalyst for other centers to emulate.

We have invited Dr. Alfred Z. Abuhamad to be our guest professor. Dr. Abuhamad serves as chairman of the department of ob.gyn. at the Eastern Virginia Medical School, Norfolk, and is the Mason C. Andrews Professor of Obstetrics and Gynecology there. He has played a key role in establishing a patient safety initiative in labor and delivery at EVMS and Sentara Healthcare, and will share, in detail, what he and his colleagues have learned in implementing this initiative.

Key Points About Patient Safety

▸ An estimated 44,000–98,000 patients die each year from errors made during hospital stays.

▸ Two-thirds of perinatal sentinel events are primarily linked to communication issues.

▸ Experience with the OB Right patient safety initiative at Eastern Virginia Medical School and Sentara Healthcare has demonstrated the importance of common language and common understanding when it comes to fetal heart rate monitoring.

▸ To significantly diminish unnecessary prematurity and its associated morbidity, patient safety initiatives should include elective induction and C-section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

Hospital safety issues have been widely reported and have received significant attention recently. However, solutions have been slow in coming. Thus, the ongoing challenge of creating the safest labor and delivery environments possible has been left with obstetricians. Although the problem is daunting, there are many steps that obstetric and gynecologic practices can take on their own that will reduce adverse events in labor and delivery as well as optimize maternal-fetal outcomes.

Separate reports published almost a decade ago by the Institute of Medicine and the American Hospital Association estimated that 44,000–98,000 patients die each year from errors made during hospital stays.

That higher death rate accounts for almost double the number of people who die in motor vehicle accidents each year in this country, and double the number of women who die annually from breast cancer, according to the Centers for Disease Control and Prevention.

The problem is so severe that Dr. Mark R. Chassin, president of the Joint Commission (an independent, not-for-profit organization that accredits and certifies more than 15,000 health care organizations and programs in the United States), noted recently that the chance of any of us being injured from simply being in a hospital and not as the result of an illness is 40% greater than the likelihood of an airline mishandling our luggage.

The problem of inconsistent and dysfunctional clinical patterns of care in both the inpatient and outpatient settings is even more alarming. One large study involving the review of 18,000 patient charts found that only 55% of patients received care in keeping with current best practices (“Epidemic of Care: A Call for Safer, Better, and More Accountable Health Care.” San Francisco: Jossey-Bass, 2003).

Approximately 5 years ago, the Joint Commission examined all perinatal “sentinel” events across the country in all types of institutions, and found that 72% of such events were linked to breakdowns in communication.

Other identified root causes included staff competency (47%), staff orientation and training (40%), inadequate fetal monitoring (34%), unavailable equipment or drugs (30%), and physician-credentialing issues (30%).

Major issues of concern in the labor and delivery setting involve the fetal heart rate tracing, iatrogenic prematurity, shoulder dystocia, and operative delivery, as well as all the verbal and written communications that are involved with each of these areas.

An American College of Obstetricians and Gynecologists survey noted that the fetal heart tracing accounts for the majority of liability claims pertaining to labor and delivery.

Labor and delivery safety programs should therefore focus primarily on these issues, and on the following:

▸ Simplifying and standardizing protocols for care.

▸ Adopting evidence-based practices.

▸ Relying more on simulation and training.

▸ Working together as a team to accomplish defined goals.

Near-Miss Reporting

The real crux of any patient safety initiative—and the element that goes hand-in-hand with each of these aspects of a program—is a “near-miss” reporting system. This is a concept that medicine borrowed from the airline industry; it involves reporting any occurrence that could have resulted in an adverse event.

A near-miss reporting program is nonpunitive, and empowers everyone involved in the care of a patient to report events and happenings that they believe have the potential to cause problems for patients. Reports are made before injury happens and are reviewed in a blame-free environment. Systems can then be analyzed and modified to minimize recurrence of these events.

In fall 2005, a collaborative effort among the academic faculty at Eastern Virginia Medical School (EVMS) in Norfolk, the obstetric community faculty in that city, and Sentara Healthcare established the OB Right program, with the mission of minimizing iatrogenic injury to the mother and infant and reducing adverse patient safety events at labor and delivery. The “near-miss report form” used by the patient safety program at EVMS and Sentara Healthcare asks for descriptions of events that were “out of the ordinary” or “made you uncomfortable.” It also asks for suggested solutions.

The program has been enormously successful. Over the past 3 years, almost 230 near-misses have been reported by our physicians, residents, and nurses. Echoing the 2004 Joint Commission report, our near-miss reports have shown us that communication issues account for at as many as 60% of these potentially dangerous situations. These reports also have helped solidify a patient safety approach that gives special attention to fetal heart rate monitoring, shoulder dystocia, iatrogenic prematurity, and operative deliveries.

Setting Up a Program

At the time the OB Right program was established, it encompassed two hospitals in the Sentara Healthcare System: Sentara Norfolk General Hospital (the academic tertiary hospital of EVMS) and Sentara Leigh Hospital, (a community hospital in Norfolk that has no 24-hour in-house obstetric coverage). The purpose of including both hospitals was to ensure that the program is successful in both settings.

A steering committee was established immediately to oversee the program, and a clinical nurse specialist was recruited to coordinate program activities and serve as the link between the program and the staff. One of the nurse specialist's first tasks was identifying ways of communicating with physicians and staff, and later, letting them know early on of program successes.

The steering committee included physician leaders from the academic and community obstetric faculty, neonatology and anesthesiology physicians, nurse leaders, hospital administrators, risk managers, and representatives from liability insurance companies.

An education and practice committee was formed to review and recommend educational modules for physicians and staff, to research and develop protocols on best practices, to review practice patterns and recommend changes, to establish a simulation lab, and to implement emergency drills.

A data committee was established to identify retrospective and prospective variables for data collection, as well as data collection methods. Its members were also assigned the jobs of conducting patient and physician satisfaction surveys and of developing a system to collect, report, and debrief faculty and staff on reported near-misses.

Members of the technology committee led an effort to identify and develop technology that would improve patient safety at labor and delivery.

Building the Program

A critical look at all available protocols is a key component of a safety initiative. Simplifying and standardizing the oxytocin order set, for instance, was something we did early on.

It's important to ensure that everyone is speaking the same language. We were particularly struck by the importance of common language and common understanding in fetal heart rate monitoring. For example, early on we surveyed EVMS residents and labor and delivery nurses about how they defined uterine tachysystole. Responses were all over the board, with more than 20 different definitions.

Without a common definition, we realized, we would have not only varying recognition of the problem at labor and delivery, but also poor communication among health team members and the potential for harming the patient.

To prevent errors of mistaking fetal heart rate for maternal heart rate during labor, we adopted the National Institute for Child Health and Human Development's definitions of uterine tachysystole and fetal heart rate patterns. This was an important precursor to the development of protocols for addressing tachysystole and enhancing communication.

We also established universal monitoring of maternal and fetal heart rates. The maternal heart rate is continuously displayed on the fetal heart rate monitor, which substantially reduces the chance for error.

In addition, we studied our cesarean section response time and developed new response time guidelines that enabled us to clearly and efficiently communicate with anesthesiology regarding the various levels of urgency involved. Ultimately, we created four cesarean section categories that provided clear communication among health care teams and allowed for data collection and review. (See box above.)

To significantly reduce unnecessary prematurity and its associated morbidity, we implemented elective induction and cesarean section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

These criteria are currently part of the national voluntary consensus standards for perinatal care in 2008 that were developed by a committee of the National Quality Forum.

Following much debate, we also implemented, at both hospitals, the universal collection of arterial and venous cord pH with every delivery. We have found this practice to be cost effective and to provide objective documentation of fetal intrapartum oxygenation. It also identifies neonates for targeted resuscitation and is a mechanism for continuous quality improvement. Given its potential controversy, however, this practice should not be at the top of the list for safety initiatives at labor and delivery.

Plans in the immediate future include a focus on shoulder dystocia, operative delivery, and triage of patients at labor and delivery.

Given the early success of OB Right, we decided to expand this program to the five other Sentara Healthcare hospitals that provide obstetric services in southeastern Virginia.

In order to achieve this goal, we have created a Clinical Effectiveness Council with physician/nurse team representation from each of the hospitals. The council meets monthly and is currently in the process of implementing key components of the OB Right program.

Keys to Success

We have learned that “buy-in” is key to an effective patient safety initiative. Hospital administration must devote the resources necessary for the success of the program, and both physicians and nurses must be at the table together and be involved as a team with a common safety goal.

A clinical safety coordinator is also essential to the success of a program. This person provides the consistency required and plays a critical role in communicating with the staff in the trenches.

Additionally, it is important to establish methods of communication early on, and to deliver and communicate tangible successes as soon as possible.

The OB Right program communicates with the health care team through posters on labor and delivery, and a newsletter that reports every 3 months on the issues and successes of the program. It also has a Web site with educational modules, near-miss reporting, meeting schedules and minutes, and other interactive tools.

Since OB Right began, we've almost eliminated elective deliveries at less than 39 weeks' gestation, and have achieved an almost-universal compliance with simultaneous maternal and fetal heart rate tracing and measurement of arterial and venous cord pH at both hospitals.

One of the major liability insurance companies sends a representative to the OB Right steering committee meetings and provides premium discounts for physician participation in the OB Right program.

As reported in the Institute of Medicine report “Crossing the Quality Chasm: A New Health System for the 21st Century,” the biggest challenge to moving toward a safer health system is changing the culture from one of blaming individuals for errors to one in which errors are treated not as personal failures but as opportunities to improve the system and prevent harm.

ELSEVIER GLOBAL MEDICAL NEWS

Quality of Care in Obstetrics

Patient safety has become an emphasized area of medicine in recent years. This is not to suggest that the issue of patient safety is new to medicine. Historically, it has been assumed to be a natural part of good medicine and the provision of good medical care.

In 1999, the Institute of Medicine released shocking statistics, estimating that as many as 98,000 people die in any given year as a result of medical errors that occur in hospitals. In the now well-cited report “To Err Is Human: Building a Safer Health Care System,” the IOM asserted that errors occur because good physicians and health care providers work within a bad system. It set a minimum goal of reducing errors by 50% over the next 5 years, and laid out a national agenda for improving patient safety.

This report was followed up by another IOM report published in 2001, “Crossing the Quality Chasm: A New Health Care System for the 21st Century.” This report further defined what kind of change is needed to “close the quality gap.” It provided overarching principles for clinicians, among others, and looked at how systems approaches can be used to implement change.

With both reports—two of many IOM studies and publications aimed at improving the nation's quality of care—a light has been shown nationally and internationally on the importance of not simply assuming that good quality care is part of medicine but, instead, emphasizing and critically analyzing the state of affairs relative to patient safety and quality of care.

Most of our institutions by now have implemented major organizational and structural changes aimed specifically at introducing safety and quality measures. These changes and structures—and the ensuing outcomes—must be monitored so that deviations from the currently available national best practices and standards of care can be identified and corrected.

In obstetrics in particular, where the litigious environment is so challenging, patient safety initiatives become even more important. For this reason, we believe that a Master Class highlighting a particular safety and quality of care initiative in obstetrics may both provide guidance and serve as a catalyst for other centers to emulate.

We have invited Dr. Alfred Z. Abuhamad to be our guest professor. Dr. Abuhamad serves as chairman of the department of ob.gyn. at the Eastern Virginia Medical School, Norfolk, and is the Mason C. Andrews Professor of Obstetrics and Gynecology there. He has played a key role in establishing a patient safety initiative in labor and delivery at EVMS and Sentara Healthcare, and will share, in detail, what he and his colleagues have learned in implementing this initiative.

Key Points About Patient Safety

▸ An estimated 44,000–98,000 patients die each year from errors made during hospital stays.

▸ Two-thirds of perinatal sentinel events are primarily linked to communication issues.

▸ Experience with the OB Right patient safety initiative at Eastern Virginia Medical School and Sentara Healthcare has demonstrated the importance of common language and common understanding when it comes to fetal heart rate monitoring.

▸ To significantly diminish unnecessary prematurity and its associated morbidity, patient safety initiatives should include elective induction and C-section bundles that require either a gestational age of at least 39 weeks or documented fetal lung maturity.

The tepid response is due largely to conventional laparoscopy having significant drawbacks. In a standing position, surgeons use a flat, 2-D image and instruments that are long and nonarticulating. Motions are counterintuitive and the learning curve, consequently, is long.

With the robotic technology currently available, such limitations are largely overcome. Advantages of the technology include a 3-D view, an increase in instrument “wrist” mobility from four to seven degrees, and movements that are significantly more intuitive.

These improvements facilitate better vision, easier suturing, and more precise dissection of tissue around sensitive areas such as major blood vessels and the ureters. And because the surgeon sits at a console unit instead of in an awkward position at the operating table, surgeon fatigue is significantly reduced.

This merging of the advantages of laparotomy and laparoscopy—and the more precise gynecologic surgery that results—is changing lymphadenectomy just as it is other types of gynecologic surgery.

The first laparoscopic radical hysterectomy was performed in June 1986; however, until recently, fewer than 1,000 cases of laparoscopic radical hysterectomy with lymphadenectomy had been reported. Now, with the availability of the da Vinci robotic system, more and more gynecologic oncologists in both teaching and community hospitals are routinely performing this procedure and other lymphadenectomies in patients with endometrial, cervical, early ovarian, fallopian tube, and other gynecologic malignancies.

In fellowship training programs specifically, the application of the technology has increased the usage of laparoscopy in gynecologic oncology—with learning curves documented as being significantly shorter than the learning curves associated with conventional laparoscopy.

Pelvic Lymphadenectomy

In terms of patient selection, there are no more limitations to the use of the robotic approach than with conventional laparoscopy. Robotic lymph node dissection can be offered to all patients for whom laparoscopy is deemed appropriate. It is advantageous, in fact, for women who are obese since the robotic approach bypasses the fulcrum effect that is especially challenging in patients with a thick abdominal wall.

As with other robotic-assisted gynecologic procedures, robotic lymphadenectomy is performed using the da Vinci system, an integrated computer-based system consisting of three interactive robotic arms and a camera arm with a remote control console. The system is the only robotic device with FDA approval for use in gynecologic surgery at the present time.

For pelvic lymphadenectomy, with the patient under general endotracheal anesthesia, we place our primary robotic trocar (a 12-mm port) through the umbilicus for the laparoscope. Two 8-mm trocars are placed 8–10 cm bilaterally and 2–3 cm lower than the umbilicus. Such placement enables optimal movement of the robotic arms and minimizes the risk of collisions (

A 10- to 12-mm assistant port is then placed on one side (most often the right side) of the umbilicus (between the camera port and one of the 8-mm trocars, 1–2 cm high). Through this port, the assistant can introduce suture and instrumentation used for retraction and suction/irrigation, as well as remove specimens. We use the Harris-Kronner Uterine Manipulator-Injector (Humi) for our gynecologic cancer patients whenever possible. Although some physicians believe its use during either conventional or robotic-assisted laparoscopy may cause dissemination of the cancer, we have found this not to be the case.

In a series of cases in which we performed laparoscopic staging for both cervical and endometrial cancer using the manipulator and compared it with conventional staging through laparotomy, we found no compromise in recurrence or in the survival rate (Int. J. Gynecol. Cancer 2007:17;1075–82 and J. Minim. Invasive Gynecol. 2008:15;181–7).

Once the trocars are placed, the patient is placed in a steep Trendelenburg's position and the robotic tower is docked between the patient's legs. The surgeon sits at a console, and the assistant stands to the patient's left or right side. Occasionally, we use a second assistant—most often when the assistant cannot adequately reach the vagina of an obese patient.

After a survey of the pelvic cavity to rule out any sign of metastases in the abdominal cavity and to identify any associated pathology that needs to be treated, such as adhesions that need to be lysed, we proceed with the lymphadenectomy.

The procedure is usually performed with bipolar forceps placed through the left robotic port, and a monopolar electrosurgical spatula, or scissors, placed through the right port. If necessary, a 10-mm clips applier or blood vessel sealing devices can be placed through the assistant's port.

Pelvic wall dissection involves coagulating and cutting the round ligaments on either side of the pelvic wall and then making an incision over the peritoneum between the infundibular pelvic ligament and the vessels in the pelvic side wall.

The retroperitoneal space is developed and the ureter is identified medially, and if the ovary is to be removed, which is the case in most patients, the infundibular ligament is isolated, desiccated, and divided using the bipolar forceps and scissors.

The paravesical and pararectal spaces are then developed by retracting the umbilical ligament (the superior vesicle artery) medially and performing blunt dissection between this artery and the pelvic side wall.

The obturator nerve can usually be identified at this point, and the obturator fossa nodes and hypogastric lymph nodes can be removed. Occasionally, when the obturator nerve cannot be identified initially, the obturator fossa nodes must be dissected and retracted medially, under the external iliac vein. Then, when the nerve is identified under these lymph nodes using blunt dissection, all nodes from the obturator fossa all the way up to the hypogastric vessels can be resected (

After removing the lymphatic nodes from the obturator fossa and the hypogastric vessels, we remove all nodes along the external iliac vessels from the external common iliac artery down to the deep circumflex vein.

Blunt and sharp dissection performed with the scissors, forceps, and suction irrigator is used for resection of all these nodes, and bipolar and unipolar forceps are used to achieve hemostasis and to clear the lymphatic channels (

This is the same process we follow during conventional laparoscopic lymphadenectomy, except that the conventional laparoscopic approach can be done using ultrasonic shears, which are multifunctional and may lower the risk for tissue damage. With the current da Vinci system, we are limited to using electrosurgery instrumentation for coagulation and cutting, but we have found that these instruments are more than adequate.

Para-Aortic Lymphadenectomy

For para-aortic lymphadenectomies in which node dissection will extend up to the inferior mesenteric artery, the trocar positioning is the same as for pelvic lymphadenectomy.

If node dissection above the inferior mesenteric artery is planned, however, trocar placement must be modified, with the camera port placed approximately 5–8 cm above the umbilicus and the other trocars adjusted accordingly, based on the different camera port placement (

The peritoneum is incised over the right common iliac artery, and the incision is extended cephalad over the inferior vena cava and lower abdominal aorta to the level of the duodenum, above the inferior mesenteric artery. The right ureter should be identified first, with the retroperitoneal space gradually developed toward the left side, and the left ureter then identified (

The assistant port or the fourth arm of the robot is used to retract the ureter or the bowel laterally. The lymph adenectomy starts from below and gradually extends upward toward the insertion of the ovarian vein to the vena cava on the right side and the renal vein on the left side.

The nodes are removed using the same technique as for pelvic lymphadenectomy, with bipolar forceps used as a grasping forceps and for coagulation of the small blood vessels and unipolar forceps used for cutting and achieving hemostasis for these vessels (

Final Steps, Outcomes

In patients also undergoing a hysterectomy, lymphadenectomy can be performed before or after the hysterectomy, depending on the indication.

Lymph nodes dissected with the robotic approach can be stored and removed in a laparoscopic bag that is introduced through the assistant's port. In patients undergoing a hysterectomy, the bag can be stored in the abdomen during the procedure and then removed through the vagina afterward.

After we complete lymphadenectomy, the pelvic cavity is thoroughly irrigated, Seprafilm slurry is applied to prevent adhesions, and all trocar sites are routinely closed. Closing all ports, even the 8-mm sites, is important since a small bowel trocar-site herniation has been reported. We also inject Marcaine in all trocar sites. Depending on the patient's condition, she can be discharged on the same day or after 1 or 2 days.

Gynecologic surgeons have developed various techniques for robotic-assisted laparoscopic lymphadenectomy that include different placement of the trocar sites. We have been performing robotic lymphadenectomy and radical hysterectomy since 2003 and have modified our technique to be as feasible and reproducible as possible.

We recently compared the experiences of 43 women with early cervical cancer who were treated with either robotic radical hysterectomy with pelvic lymphadenectomy or laparoscopic radical hysterectomy with pelvic lymphadenectomy.

The treatments—using either conventional laparoscopy or robotic-assisted laparoscopy—were equivalent with respect to operative time, blood loss, hospital stay, and oncologic outcome. The mean pelvic lymph node count was similar in the two groups (JSLS 2008;12:227–37).

While this analysis did not include cases involving open radical hysterectomy and lymphadenectomy, we know from other series and reports that the number of resected lymph nodes increases with a laparoscopic approach, whether or not it is robotically performed.

In studies in our fellowship training program, moreover, we have found that fellows who have less experience with laparoscopic surgery than attendings achieved the same number of lymph node retrievals as the attendings through either conventional laparoscopic or robotic lymphadenectomy. Such ease and reproducibility portends well for the future of robotic technology in gynecologic oncology.

Some of the major advantages of robotic-assisted surgery are that it provides 3-D views, allows intuitive motions, and involves less operator fatigue. In addition, tremor filtration facilitates more precise movements. It entails a shorter learning curve than does conventional laparoscopy. Robotic-assisted surgery has also paved a pathway to telesurgery and telementoring. This may expand the availability of advanced minimally invasive surgeries throughout the globe.

Dr. Nezhat had no financial conflicts of interest to disclose.

Robotic-Assisted Lymphadenectomy

Despite the early, pioneering efforts of physicians such as Dr. Denis Querleu in France, as well as Dr. Joel Childers and our author, Dr. Farr R. Nezhat, in the United States, the acceptance of laparoscopic surgery by gynecologic oncologists has been lackluster at best. Lately, however, no area of our specialty has shown faster adaptation to minimally invasive surgery than has gynecologic oncology. In fact, secondary to the interest in laparoscopic oncologic procedures, the AAGL has recently created a gynecologic oncology specialty group. Due to his vast experience, Dr. Nezhat has been given a leadership role in this endeavor. It is this editor's belief that the utilization of robotics is the single factor that has created such a rapid movement within the gyne-oncology community to embrace laparoscopic surgery. The 3-D visualization, combined with the seven degrees of motion of robotic instrumentation, has enabled the gynecologic oncologist to work precisely and efficiently. Despite his vast experience in laparoscopic surgery, our guest author was an early convert to robotic-assisted surgery.

Dr. Nezhat is the director of minimally invasive surgery and gynecologic robotics, as well as chief of the gynecologic robotic, minimally invasive surgery fellowship, in the division of gynecologic oncology at St. Luke's-Roosevelt Hospital Center, New York. He has written more than 100 articles in peer-reviewed journals, many of which involve laparoscopic surgery. Dr. Nezhat is truly one of the thought leaders of our specialty. It is an honor to have him write this current column of the Master Class in gynecologic surgery.

The tepid response is due largely to conventional laparoscopy having significant drawbacks. In a standing position, surgeons use a flat, 2-D image and instruments that are long and nonarticulating. Motions are counterintuitive and the learning curve, consequently, is long.

With the robotic technology currently available, such limitations are largely overcome. Advantages of the technology include a 3-D view, an increase in instrument “wrist” mobility from four to seven degrees, and movements that are significantly more intuitive.

These improvements facilitate better vision, easier suturing, and more precise dissection of tissue around sensitive areas such as major blood vessels and the ureters. And because the surgeon sits at a console unit instead of in an awkward position at the operating table, surgeon fatigue is significantly reduced.

This merging of the advantages of laparotomy and laparoscopy—and the more precise gynecologic surgery that results—is changing lymphadenectomy just as it is other types of gynecologic surgery.

The first laparoscopic radical hysterectomy was performed in June 1986; however, until recently, fewer than 1,000 cases of laparoscopic radical hysterectomy with lymphadenectomy had been reported. Now, with the availability of the da Vinci robotic system, more and more gynecologic oncologists in both teaching and community hospitals are routinely performing this procedure and other lymphadenectomies in patients with endometrial, cervical, early ovarian, fallopian tube, and other gynecologic malignancies.

In fellowship training programs specifically, the application of the technology has increased the usage of laparoscopy in gynecologic oncology—with learning curves documented as being significantly shorter than the learning curves associated with conventional laparoscopy.

Pelvic Lymphadenectomy

In terms of patient selection, there are no more limitations to the use of the robotic approach than with conventional laparoscopy. Robotic lymph node dissection can be offered to all patients for whom laparoscopy is deemed appropriate. It is advantageous, in fact, for women who are obese since the robotic approach bypasses the fulcrum effect that is especially challenging in patients with a thick abdominal wall.

As with other robotic-assisted gynecologic procedures, robotic lymphadenectomy is performed using the da Vinci system, an integrated computer-based system consisting of three interactive robotic arms and a camera arm with a remote control console. The system is the only robotic device with FDA approval for use in gynecologic surgery at the present time.

For pelvic lymphadenectomy, with the patient under general endotracheal anesthesia, we place our primary robotic trocar (a 12-mm port) through the umbilicus for the laparoscope. Two 8-mm trocars are placed 8–10 cm bilaterally and 2–3 cm lower than the umbilicus. Such placement enables optimal movement of the robotic arms and minimizes the risk of collisions (

A 10- to 12-mm assistant port is then placed on one side (most often the right side) of the umbilicus (between the camera port and one of the 8-mm trocars, 1–2 cm high). Through this port, the assistant can introduce suture and instrumentation used for retraction and suction/irrigation, as well as remove specimens. We use the Harris-Kronner Uterine Manipulator-Injector (Humi) for our gynecologic cancer patients whenever possible. Although some physicians believe its use during either conventional or robotic-assisted laparoscopy may cause dissemination of the cancer, we have found this not to be the case.

In a series of cases in which we performed laparoscopic staging for both cervical and endometrial cancer using the manipulator and compared it with conventional staging through laparotomy, we found no compromise in recurrence or in the survival rate (Int. J. Gynecol. Cancer 2007:17;1075–82 and J. Minim. Invasive Gynecol. 2008:15;181–7).

Once the trocars are placed, the patient is placed in a steep Trendelenburg's position and the robotic tower is docked between the patient's legs. The surgeon sits at a console, and the assistant stands to the patient's left or right side. Occasionally, we use a second assistant—most often when the assistant cannot adequately reach the vagina of an obese patient.

After a survey of the pelvic cavity to rule out any sign of metastases in the abdominal cavity and to identify any associated pathology that needs to be treated, such as adhesions that need to be lysed, we proceed with the lymphadenectomy.

The procedure is usually performed with bipolar forceps placed through the left robotic port, and a monopolar electrosurgical spatula, or scissors, placed through the right port. If necessary, a 10-mm clips applier or blood vessel sealing devices can be placed through the assistant's port.

Pelvic wall dissection involves coagulating and cutting the round ligaments on either side of the pelvic wall and then making an incision over the peritoneum between the infundibular pelvic ligament and the vessels in the pelvic side wall.

The retroperitoneal space is developed and the ureter is identified medially, and if the ovary is to be removed, which is the case in most patients, the infundibular ligament is isolated, desiccated, and divided using the bipolar forceps and scissors.

The paravesical and pararectal spaces are then developed by retracting the umbilical ligament (the superior vesicle artery) medially and performing blunt dissection between this artery and the pelvic side wall.

The obturator nerve can usually be identified at this point, and the obturator fossa nodes and hypogastric lymph nodes can be removed. Occasionally, when the obturator nerve cannot be identified initially, the obturator fossa nodes must be dissected and retracted medially, under the external iliac vein. Then, when the nerve is identified under these lymph nodes using blunt dissection, all nodes from the obturator fossa all the way up to the hypogastric vessels can be resected (

After removing the lymphatic nodes from the obturator fossa and the hypogastric vessels, we remove all nodes along the external iliac vessels from the external common iliac artery down to the deep circumflex vein.

Blunt and sharp dissection performed with the scissors, forceps, and suction irrigator is used for resection of all these nodes, and bipolar and unipolar forceps are used to achieve hemostasis and to clear the lymphatic channels (

This is the same process we follow during conventional laparoscopic lymphadenectomy, except that the conventional laparoscopic approach can be done using ultrasonic shears, which are multifunctional and may lower the risk for tissue damage. With the current da Vinci system, we are limited to using electrosurgery instrumentation for coagulation and cutting, but we have found that these instruments are more than adequate.

Para-Aortic Lymphadenectomy

For para-aortic lymphadenectomies in which node dissection will extend up to the inferior mesenteric artery, the trocar positioning is the same as for pelvic lymphadenectomy.

If node dissection above the inferior mesenteric artery is planned, however, trocar placement must be modified, with the camera port placed approximately 5–8 cm above the umbilicus and the other trocars adjusted accordingly, based on the different camera port placement (

The peritoneum is incised over the right common iliac artery, and the incision is extended cephalad over the inferior vena cava and lower abdominal aorta to the level of the duodenum, above the inferior mesenteric artery. The right ureter should be identified first, with the retroperitoneal space gradually developed toward the left side, and the left ureter then identified (

The assistant port or the fourth arm of the robot is used to retract the ureter or the bowel laterally. The lymph adenectomy starts from below and gradually extends upward toward the insertion of the ovarian vein to the vena cava on the right side and the renal vein on the left side.

The nodes are removed using the same technique as for pelvic lymphadenectomy, with bipolar forceps used as a grasping forceps and for coagulation of the small blood vessels and unipolar forceps used for cutting and achieving hemostasis for these vessels (

Final Steps, Outcomes

In patients also undergoing a hysterectomy, lymphadenectomy can be performed before or after the hysterectomy, depending on the indication.

Lymph nodes dissected with the robotic approach can be stored and removed in a laparoscopic bag that is introduced through the assistant's port. In patients undergoing a hysterectomy, the bag can be stored in the abdomen during the procedure and then removed through the vagina afterward.

After we complete lymphadenectomy, the pelvic cavity is thoroughly irrigated, Seprafilm slurry is applied to prevent adhesions, and all trocar sites are routinely closed. Closing all ports, even the 8-mm sites, is important since a small bowel trocar-site herniation has been reported. We also inject Marcaine in all trocar sites. Depending on the patient's condition, she can be discharged on the same day or after 1 or 2 days.

Gynecologic surgeons have developed various techniques for robotic-assisted laparoscopic lymphadenectomy that include different placement of the trocar sites. We have been performing robotic lymphadenectomy and radical hysterectomy since 2003 and have modified our technique to be as feasible and reproducible as possible.

We recently compared the experiences of 43 women with early cervical cancer who were treated with either robotic radical hysterectomy with pelvic lymphadenectomy or laparoscopic radical hysterectomy with pelvic lymphadenectomy.

The treatments—using either conventional laparoscopy or robotic-assisted laparoscopy—were equivalent with respect to operative time, blood loss, hospital stay, and oncologic outcome. The mean pelvic lymph node count was similar in the two groups (JSLS 2008;12:227–37).

While this analysis did not include cases involving open radical hysterectomy and lymphadenectomy, we know from other series and reports that the number of resected lymph nodes increases with a laparoscopic approach, whether or not it is robotically performed.

In studies in our fellowship training program, moreover, we have found that fellows who have less experience with laparoscopic surgery than attendings achieved the same number of lymph node retrievals as the attendings through either conventional laparoscopic or robotic lymphadenectomy. Such ease and reproducibility portends well for the future of robotic technology in gynecologic oncology.

Some of the major advantages of robotic-assisted surgery are that it provides 3-D views, allows intuitive motions, and involves less operator fatigue. In addition, tremor filtration facilitates more precise movements. It entails a shorter learning curve than does conventional laparoscopy. Robotic-assisted surgery has also paved a pathway to telesurgery and telementoring. This may expand the availability of advanced minimally invasive surgeries throughout the globe.

Dr. Nezhat had no financial conflicts of interest to disclose.

Robotic-Assisted Lymphadenectomy

Despite the early, pioneering efforts of physicians such as Dr. Denis Querleu in France, as well as Dr. Joel Childers and our author, Dr. Farr R. Nezhat, in the United States, the acceptance of laparoscopic surgery by gynecologic oncologists has been lackluster at best. Lately, however, no area of our specialty has shown faster adaptation to minimally invasive surgery than has gynecologic oncology. In fact, secondary to the interest in laparoscopic oncologic procedures, the AAGL has recently created a gynecologic oncology specialty group. Due to his vast experience, Dr. Nezhat has been given a leadership role in this endeavor. It is this editor's belief that the utilization of robotics is the single factor that has created such a rapid movement within the gyne-oncology community to embrace laparoscopic surgery. The 3-D visualization, combined with the seven degrees of motion of robotic instrumentation, has enabled the gynecologic oncologist to work precisely and efficiently. Despite his vast experience in laparoscopic surgery, our guest author was an early convert to robotic-assisted surgery.

Dr. Nezhat is the director of minimally invasive surgery and gynecologic robotics, as well as chief of the gynecologic robotic, minimally invasive surgery fellowship, in the division of gynecologic oncology at St. Luke's-Roosevelt Hospital Center, New York. He has written more than 100 articles in peer-reviewed journals, many of which involve laparoscopic surgery. Dr. Nezhat is truly one of the thought leaders of our specialty. It is an honor to have him write this current column of the Master Class in gynecologic surgery.

The tepid response is due largely to conventional laparoscopy having significant drawbacks. In a standing position, surgeons use a flat, 2-D image and instruments that are long and nonarticulating. Motions are counterintuitive and the learning curve, consequently, is long.

With the robotic technology currently available, such limitations are largely overcome. Advantages of the technology include a 3-D view, an increase in instrument “wrist” mobility from four to seven degrees, and movements that are significantly more intuitive.

These improvements facilitate better vision, easier suturing, and more precise dissection of tissue around sensitive areas such as major blood vessels and the ureters. And because the surgeon sits at a console unit instead of in an awkward position at the operating table, surgeon fatigue is significantly reduced.

This merging of the advantages of laparotomy and laparoscopy—and the more precise gynecologic surgery that results—is changing lymphadenectomy just as it is other types of gynecologic surgery.

The first laparoscopic radical hysterectomy was performed in June 1986; however, until recently, fewer than 1,000 cases of laparoscopic radical hysterectomy with lymphadenectomy had been reported. Now, with the availability of the da Vinci robotic system, more and more gynecologic oncologists in both teaching and community hospitals are routinely performing this procedure and other lymphadenectomies in patients with endometrial, cervical, early ovarian, fallopian tube, and other gynecologic malignancies.

In fellowship training programs specifically, the application of the technology has increased the usage of laparoscopy in gynecologic oncology—with learning curves documented as being significantly shorter than the learning curves associated with conventional laparoscopy.

Pelvic Lymphadenectomy

In terms of patient selection, there are no more limitations to the use of the robotic approach than with conventional laparoscopy. Robotic lymph node dissection can be offered to all patients for whom laparoscopy is deemed appropriate. It is advantageous, in fact, for women who are obese since the robotic approach bypasses the fulcrum effect that is especially challenging in patients with a thick abdominal wall.

As with other robotic-assisted gynecologic procedures, robotic lymphadenectomy is performed using the da Vinci system, an integrated computer-based system consisting of three interactive robotic arms and a camera arm with a remote control console. The system is the only robotic device with FDA approval for use in gynecologic surgery at the present time.

For pelvic lymphadenectomy, with the patient under general endotracheal anesthesia, we place our primary robotic trocar (a 12-mm port) through the umbilicus for the laparoscope. Two 8-mm trocars are placed 8–10 cm bilaterally and 2–3 cm lower than the umbilicus. Such placement enables optimal movement of the robotic arms and minimizes the risk of collisions (

A 10- to 12-mm assistant port is then placed on one side (most often the right side) of the umbilicus (between the camera port and one of the 8-mm trocars, 1–2 cm high). Through this port, the assistant can introduce suture and instrumentation used for retraction and suction/irrigation, as well as remove specimens. We use the Harris-Kronner Uterine Manipulator-Injector (Humi) for our gynecologic cancer patients whenever possible. Although some physicians believe its use during either conventional or robotic-assisted laparoscopy may cause dissemination of the cancer, we have found this not to be the case.

In a series of cases in which we performed laparoscopic staging for both cervical and endometrial cancer using the manipulator and compared it with conventional staging through laparotomy, we found no compromise in recurrence or in the survival rate (Int. J. Gynecol. Cancer 2007:17;1075–82 and J. Minim. Invasive Gynecol. 2008:15;181–7).

Once the trocars are placed, the patient is placed in a steep Trendelenburg's position and the robotic tower is docked between the patient's legs. The surgeon sits at a console, and the assistant stands to the patient's left or right side. Occasionally, we use a second assistant—most often when the assistant cannot adequately reach the vagina of an obese patient.

After a survey of the pelvic cavity to rule out any sign of metastases in the abdominal cavity and to identify any associated pathology that needs to be treated, such as adhesions that need to be lysed, we proceed with the lymphadenectomy.

The procedure is usually performed with bipolar forceps placed through the left robotic port, and a monopolar electrosurgical spatula, or scissors, placed through the right port. If necessary, a 10-mm clips applier or blood vessel sealing devices can be placed through the assistant's port.

Pelvic wall dissection involves coagulating and cutting the round ligaments on either side of the pelvic wall and then making an incision over the peritoneum between the infundibular pelvic ligament and the vessels in the pelvic side wall.

The retroperitoneal space is developed and the ureter is identified medially, and if the ovary is to be removed, which is the case in most patients, the infundibular ligament is isolated, desiccated, and divided using the bipolar forceps and scissors.

The paravesical and pararectal spaces are then developed by retracting the umbilical ligament (the superior vesicle artery) medially and performing blunt dissection between this artery and the pelvic side wall.

The obturator nerve can usually be identified at this point, and the obturator fossa nodes and hypogastric lymph nodes can be removed. Occasionally, when the obturator nerve cannot be identified initially, the obturator fossa nodes must be dissected and retracted medially, under the external iliac vein. Then, when the nerve is identified under these lymph nodes using blunt dissection, all nodes from the obturator fossa all the way up to the hypogastric vessels can be resected (

After removing the lymphatic nodes from the obturator fossa and the hypogastric vessels, we remove all nodes along the external iliac vessels from the external common iliac artery down to the deep circumflex vein.

Blunt and sharp dissection performed with the scissors, forceps, and suction irrigator is used for resection of all these nodes, and bipolar and unipolar forceps are used to achieve hemostasis and to clear the lymphatic channels (

This is the same process we follow during conventional laparoscopic lymphadenectomy, except that the conventional laparoscopic approach can be done using ultrasonic shears, which are multifunctional and may lower the risk for tissue damage. With the current da Vinci system, we are limited to using electrosurgery instrumentation for coagulation and cutting, but we have found that these instruments are more than adequate.

Para-Aortic Lymphadenectomy

For para-aortic lymphadenectomies in which node dissection will extend up to the inferior mesenteric artery, the trocar positioning is the same as for pelvic lymphadenectomy.

If node dissection above the inferior mesenteric artery is planned, however, trocar placement must be modified, with the camera port placed approximately 5–8 cm above the umbilicus and the other trocars adjusted accordingly, based on the different camera port placement (

The peritoneum is incised over the right common iliac artery, and the incision is extended cephalad over the inferior vena cava and lower abdominal aorta to the level of the duodenum, above the inferior mesenteric artery. The right ureter should be identified first, with the retroperitoneal space gradually developed toward the left side, and the left ureter then identified (

The assistant port or the fourth arm of the robot is used to retract the ureter or the bowel laterally. The lymph adenectomy starts from below and gradually extends upward toward the insertion of the ovarian vein to the vena cava on the right side and the renal vein on the left side.

The nodes are removed using the same technique as for pelvic lymphadenectomy, with bipolar forceps used as a grasping forceps and for coagulation of the small blood vessels and unipolar forceps used for cutting and achieving hemostasis for these vessels (

Final Steps, Outcomes

In patients also undergoing a hysterectomy, lymphadenectomy can be performed before or after the hysterectomy, depending on the indication.

Lymph nodes dissected with the robotic approach can be stored and removed in a laparoscopic bag that is introduced through the assistant's port. In patients undergoing a hysterectomy, the bag can be stored in the abdomen during the procedure and then removed through the vagina afterward.

After we complete lymphadenectomy, the pelvic cavity is thoroughly irrigated, Seprafilm slurry is applied to prevent adhesions, and all trocar sites are routinely closed. Closing all ports, even the 8-mm sites, is important since a small bowel trocar-site herniation has been reported. We also inject Marcaine in all trocar sites. Depending on the patient's condition, she can be discharged on the same day or after 1 or 2 days.

Gynecologic surgeons have developed various techniques for robotic-assisted laparoscopic lymphadenectomy that include different placement of the trocar sites. We have been performing robotic lymphadenectomy and radical hysterectomy since 2003 and have modified our technique to be as feasible and reproducible as possible.

We recently compared the experiences of 43 women with early cervical cancer who were treated with either robotic radical hysterectomy with pelvic lymphadenectomy or laparoscopic radical hysterectomy with pelvic lymphadenectomy.

The treatments—using either conventional laparoscopy or robotic-assisted laparoscopy—were equivalent with respect to operative time, blood loss, hospital stay, and oncologic outcome. The mean pelvic lymph node count was similar in the two groups (JSLS 2008;12:227–37).

While this analysis did not include cases involving open radical hysterectomy and lymphadenectomy, we know from other series and reports that the number of resected lymph nodes increases with a laparoscopic approach, whether or not it is robotically performed.

In studies in our fellowship training program, moreover, we have found that fellows who have less experience with laparoscopic surgery than attendings achieved the same number of lymph node retrievals as the attendings through either conventional laparoscopic or robotic lymphadenectomy. Such ease and reproducibility portends well for the future of robotic technology in gynecologic oncology.

Some of the major advantages of robotic-assisted surgery are that it provides 3-D views, allows intuitive motions, and involves less operator fatigue. In addition, tremor filtration facilitates more precise movements. It entails a shorter learning curve than does conventional laparoscopy. Robotic-assisted surgery has also paved a pathway to telesurgery and telementoring. This may expand the availability of advanced minimally invasive surgeries throughout the globe.

Dr. Nezhat had no financial conflicts of interest to disclose.

Robotic-Assisted Lymphadenectomy

Despite the early, pioneering efforts of physicians such as Dr. Denis Querleu in France, as well as Dr. Joel Childers and our author, Dr. Farr R. Nezhat, in the United States, the acceptance of laparoscopic surgery by gynecologic oncologists has been lackluster at best. Lately, however, no area of our specialty has shown faster adaptation to minimally invasive surgery than has gynecologic oncology. In fact, secondary to the interest in laparoscopic oncologic procedures, the AAGL has recently created a gynecologic oncology specialty group. Due to his vast experience, Dr. Nezhat has been given a leadership role in this endeavor. It is this editor's belief that the utilization of robotics is the single factor that has created such a rapid movement within the gyne-oncology community to embrace laparoscopic surgery. The 3-D visualization, combined with the seven degrees of motion of robotic instrumentation, has enabled the gynecologic oncologist to work precisely and efficiently. Despite his vast experience in laparoscopic surgery, our guest author was an early convert to robotic-assisted surgery.

Dr. Nezhat is the director of minimally invasive surgery and gynecologic robotics, as well as chief of the gynecologic robotic, minimally invasive surgery fellowship, in the division of gynecologic oncology at St. Luke's-Roosevelt Hospital Center, New York. He has written more than 100 articles in peer-reviewed journals, many of which involve laparoscopic surgery. Dr. Nezhat is truly one of the thought leaders of our specialty. It is an honor to have him write this current column of the Master Class in gynecologic surgery.

Despite several decades of extensive research into its pathogenesis, preeclampsia continues to be a syndrome of unknown etiology.

Several theories on the mechanisms leading to preeclampsia have been proposed, all based on numerous pathophysiological abnormalities reported in association with the heterogeneous disorder.

These theories, which have been developed largely during the past 2 decades, involve abnormalities such as impaired trophoblast differentiation and invasion, placental and endothelial dysfunction, immune maladaptation to paternal antigens, an exaggerated systemic inflammatory response, and a state of imbalance between proangiogenic and antiangiogenic factors.

As evidence for these theories has unfolded, investigators have identified numerous risk factors for preeclampsia. Most of them are preexisting risk factors that can be identified either before a patient becomes pregnant or early in the pregnancy. (See box below.)

The disorder's pathogenesis can vary in women with different risk factors or different times of onset. In women with previous preeclampsia, for example, the risk for developing recurrent preeclampsia varies depending on the underlying mechanism and the outcome in the previous pregnancy.

What this means is that even as investigators work to improve our understanding of the disorder, we as clinicians have an immediate opportunity—and responsibility—to identify patients who are at risk for preeclampsia, or recurrent preeclampsia, during preconception counseling or early in gestation.

We can then work with at-risk patients to optimize their health before conception and to carefully manage maternal and fetal well-being during pregnancy.

Women with a history of previous preeclampsia—even those who suffered serious adverse outcomes—should be counseled about their risks and reassured about our ability to optimize outcomes through vigilant monitoring, early detection of complications, and timely delivery.

And in an effort to improve their long-term health, these women should also be counseled about an increased risk for cardiovascular disease and ischemic stroke later in their lives.

Common Scenarios

A healthy 22-year-old woman with an ideal body weight and no preexisting medical risk factors who plans to become pregnant for the first time.

This patient's risk for preeclampsia is low (only 1%-2%). If preeclampsia occurs, it is likely to be mild, with an onset near term or intrapartum, and with generally good outcomes.

Nevertheless, it is important to inquire about any family history of preeclampsia or cardiovascular disease in this type of patient, and to be aware that women who themselves were born small for gestational age have an increased risk for preeclampsia, as does any woman whose husband or partner fathered a preeclamptic pregnancy in another woman.

Certain changes and events can also occur during pregnancy that will increase her risk. If, during antenatal care, ultrasound reveals multifetal gestation or unexplained fetal growth restriction, for instance, her risk of preeclampsia will increase substantially. (See box, page 9, top right.)

Likewise, if she develops gestational hypertension, her risk will increase to 25%-50% based on gestational age at the time the hypertension developed.

Several recently published studies have reported an association between maternal infections and an increased risk of preeclampsia as well. (Infections probably increase a maternal inflammatory response that already is engendered by the pregnancy itself.)

A systematic review published in 2006 found that the odds ratio for preeclampsia was 1.57 in women with urinary tract infections, and 1.76 in women with periodontal disease (N. Engl. J. Med. 2006;355:992-1005).

Unfortunately, the various biomarkers that have been proposed to predict which women are likely to develop preeclampsia—from serum placental growth factor to asymmetric dimethylarginine—have not been shown to be reliable and are not predictive or specific enough for use in clinical practice.

Likewise, supplementation with fish oil, vitamin E, vitamin C, low-dose aspirin, or calcium is not recommended for the prevention of preeclampsia in the young woman with no risk factors.

A 42-year-old who is trying to become pregnant for the first time.

This patient's older age is itself a risk factor for preeclampsia. An older age also often means more body weight and a higher likelihood of chronic hypertension or diabetes, as well as an increased likelihood that donated gametes were used, all of which can significantly increase risk.

As in the case of the younger patient, risk evaluation and management should begin before conception. Family history, personal birth history, and the history of the patient's husband or partner should be explored.

And because a high body mass index is a proven risk factor—as is insulin resistance, which is often linked with obesity—patients who are overweight or obese should be encouraged to lose weight and achieve a healthy BMI.

The risks associated with preexisting medical conditions like hypertension and diabetes vary depending on the conditions' severity.

Studies show, for instance, that women with mild hypertension before conception or early in pregnancy have a 15% rate of preeclampsia, whereas women with severe prepregnancy hypertension have a nearly 50% risk.

In all cases, women with chronic hypertension or diabetes should have their blood pressure and glucose levels optimized before conception, and then controlled throughout their pregnancy.

When assisted reproductive technology is planned, a discussion about the increased risk for preeclampsia that is caused by donated gametes is important, because donor insemination or the use of donated oocytes affects the maternal-fetal immune interaction and increases the risk of preeclampsia to as much as 35%.

Because multifetal gestation is more common with ART than with natural birth and is another risk factor for preeclampsia, this patient's overall risk can also be minimized by reducing the number of transferred embryos and by avoiding hyperstimulation when ovulation induction is required.

Just as in the case of the younger woman, unfortunately, we have little if anything else to offer this patient for the prevention of preeclampsia.

These women can be offered calcium, however. A recent review by the Food and Drug Administration concluded that any benefit with respect to preeclampsia is inconclusive and “unlikely” (Nutr. Rev. 2007;65:78-87).

However, in a 2007 Cochrane review of 12 clinical studies, calcium supplementation was associated with a reduction in the rate of preeclampsia, particularly in populations at high risk and in those with diets deficient in calcium (BJOG 2007;114:933-43).

Management should include a baseline metabolic profile and complete blood count, as well as baseline urinalysis; this information can be helpful if later laboratory studies are needed to assess the function of organ systems likely to be affected by preeclampsia.

Serial ultrasonography as well as uterine Doppler studies at 18-20 weeks should also be employed. The Doppler studies are a useful tool for assessing the velocity of the uterine artery blood flow.

An increased resistance index and/or the presence of uterine artery diastolic notching suggests an increased risk of preeclampsia (as much as a sixfold increased risk) and the need for more vigilant monitoring and care.

A woman who developed severe preeclampsia at 26 weeks' gestation in her first pregnancy. She wants a child but is afraid—terribly and understandably frightened—of a second pregnancy because her first baby was born prematurely and died after about 100 days in the NICU.

We can and should reassure this patient that her loss does not mean she should forego becoming pregnant again, and that with proper monitoring, she has a significant chance of having a healthy baby.

A woman's risk of preeclampsia recurrence will depend on whether or not she has any preexisting risk factors, as well as the gestational age at the time of onset of preeclampsia in her first pregnancy.

The reported rate of recurrent preeclampsia ranges from 11.5% to 65%, with the highest rates being reported in women whose previous preeclampsia occurred in the second trimester. This patient's risk of recurrent preeclampsia is about 50%.

In general, recurrent preeclampsia is more likely to be severe and to develop preterm than is first-time preeclampsia. We can reassure this patient, however, that an early onset of preeclampsia in the first pregnancy does not necessarily mean that the disorder will have an early onset in the second pregnancy.

In a study published in 1991, among women with previous preeclampsia in the second trimester, preeclampsia recurred in the second trimester in 21%, at 28-36 weeks in 21%, and at term in 23% (Am. J. Obstet. Gynecol. 1991;165:1408-12).

Women with a history of eclampsia have a rate of recurrence of 1%-2% and a rate of subsequent preeclampsia of 22%-35%. Women with a history of HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome have a rate of preeclampsia in subsequent pregnancies of 16%-52% and, according to the most reliable data, a rate of recurrent HELLP syndrome of less than 5%.

Management for this patient ideally begins before conception, with an extensive evaluation and an in-depth history to uncover preexisting risk factors and/or medical conditions associated with the disorder.

This will allow proper counseling about the magnitude of risk for preeclampsia recurrence, and will guide you as you manage the pregnancy. (See box, bottom left.)

Knowing when she developed preeclampsia is important, as are details about maternal complications such as HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, pulmonary edema, or renal failure, for instance; about fetal complications, such as fetal growth restriction; and about previous laboratory test results, as well as placental pathology.

The status of any comorbidities, such as high BMI or high blood pressure, should be optimized before conception, and vigilant monitoring—including early and serial ultrasonography, uterine Doppler assessment at 18-20 weeks, and laboratory testing as indicated—should be instituted to minimize and manage her risk.

By detecting complications early and monitoring for signs and symptoms of preeclampsia—and then hospitalizing her if you detect severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia—you can ensure optimal outcomes.

This patient will probably want to know about the value of various biomarkers and supplements, such as fish oil and vitamins C and E, and again, we need to explain that the best studies have shown minimal to no benefit and do not support their use.

The three large randomized trials looking at vitamin E supplementation, for example, showed no effect on the rate of preeclampsia, its severity, or the rate of adverse neonatal outcomes.

None of the randomized trials on calcium supplementation included women with a previous history of preeclampsia, so the benefit for this indication remains unclear. Nevertheless, because calcium is beneficial for any pregnancy, we recommend it.

The greatest benefits of low-dose aspirin may come for this patient. A recent meta-analysis of 31 randomized trials found a 14% reduction in recurrent preeclampsia—higher than that seen for first-time preeclampsia (Lancet 2007;369:1791-8). Low-dose aspirin has also proved to be safe. We recommend 81 mg daily beginning at 12 weeks' gestation, and suggest discontinuing aspirin with the development of preeclampsia.

If the patient has documented evidence of antiphospholipid antibody syndrome, she should receive prophylactic-dose heparin in addition to low-dose aspirin once fetal viability is confirmed.

A woman who had late-occurring mild preeclampsia in her first pregnancy, and is planning a second child.

This patient experienced the most common presentation of preeclampsia, and fortunately has a fairly low risk for recurrence (about 10%). Chances are also likely that if preeclampsia recurs, it will recur at term.

This risk can be minimized and a good outcome ensured by following the same approach to history taking, counseling, and optimizing health before conception, as well as careful monitoring during pregnancy to detect complications early.

Risks Later in Life

Today, counseling women with a history of preeclampsia involves more than assessing and minimizing risks for recurrence of the disorder. It also involves discussing the now-substantial body of literature that suggests that women whose pregnancies are complicated by preeclampsia and/or fetal growth restriction have an increased risk for future cardiovascular disease and ischemic stroke.

These women require close follow-up after their pregnancies so that their long-term risks can be reduced or avoided through the use of preventive strategies and approaches to care.

Preeclampsia and fetal growth restriction are both vascular-related pregnancy complications, and they share similar risk factors and pathophysiological abnormalities, such as endothelial dysfunction.

It's unclear exactly what mechanisms account for the relationship among these complications and the increased risk of subsequent cardiovascular disease, but it increasingly seems likely that these women have a predisposition to vascular and metabolic disease: a constitutional risk.

Epidemiologic and case-control studies published in the last 10 years—many of them in the nonobstetric literature—have evaluated the associations, and last year a systematic review and meta-analysis of these studies reported a relative risk for chronic hypertension of 3.7 after approximately 14 years of average follow-up, a relative risk of 2.16 for ischemic heart disease after about 11 years of follow-up, and a relative risk of 1.8 for ischemic stroke after about 10 years (BMJ 2007;335:974-85).

In addition, overall mortality after preeclampsia was increased by a relative risk of approximately 1.5 after 14.5 years of follow-up.

In a recently published intergenerational case-control study, Dutch investigators looked at 106 women whose pregnancies were complicated by preeclampsia or fetal growth restriction, a control group of 106 women with normal pregnancies, and each woman's mother and father.

They found significant intergenerational similarities in cardiovascular risk profiles between the women after preeclampsia or fetal growth restriction and their parents, such as higher fasting glucose levels that could not be explained by differences in BMI.

Intergenerational similarities were also found for hypertension, waist circumference, and metabolic syndrome (Hypertension 2008;51:1034-41).

ELSEVIER GLOBAL MEDICAL NEWS

Preeclampsia, Part 3

The exact incidence of preeclampsia is unknown, but in its mild form it is estimated to affect up to 10% of all pregnancies. Indeed, it is one of the most common complications of pregnancy. In a smaller number of cases (just under 1% of pregnancies), the disorder develops as severe preeclampsia.

In the past two Master Class installments on preeclampsia, we have discussed how the disorder presents in various ways, afflicting women of different age groups, of varying parity, and with associated medical complications or the lack thereof.

We have also discussed appropriate evaluation and management protocols. The spectrum of disease is such that it spans the very mild (requiring modest intervention) to the very severe (requiring immediate and aggressive intervention strategies). As we saw in the last installment, it is important to view preeclampsia as a multifaceted disease continuum in which designations of “mild” and “severe” are not necessarily fixed.

The variable presentation of the disorder—and the fact that it cannot be precisely predicted or prevented—may in itself be challenging to the practitioner, as he or she counsels patients who are contemplating pregnancies and may be at risk for preeclampsia.

There are certain predisposing medical and sociodemographic factors, however, that are clearly important and that can be useful if they are integrated into an evaluation and management algorithm. Integrating our knowledge of risk factors allows for the most appropriate counseling to be delivered, and the most appropriate management plan to be developed, on a case-by-case basis.

I have invited Dr. Baha Sibai to once again address the topic of preeclampsia in this third and final installment of our series on the disorder. Dr. Sibai is professor of obstetrics and gynecology at the University of Cincinnati and an international expert on preeclampsia and eclampsia, as well as a leader in both clinical care and research in this area.

In this case, we've taken a different approach to presenting the material. We think our case-by-case format will be practical and applicable to the practitioner who is counseling a number of patients who present with varying histories and risk factors.

How to Manage Recurrence Risk

Preconception

▸ Identify risk factors.

▸ Review outcome of previous pregnancy.

▸ Optimize maternal health.

First Trimester

▸ Perform ultrasonography for dating and assessing fetal number.

▸ Order baseline metabolic profile and complete blood count.

▸ Perform baseline urinalysis.

▸ Offer first-trimester combined screening.

▸ If antiphospholipid syndrome is documented, start low-dose aspirin and heparin. Otherwise, offer low-dose aspirin therapy at 12 weeks' gestation.

Second Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ Perform ultrasonography at 18-22 weeks' gestation for fetal anomaly evaluation and to rule out molar gestation.

▸ Perform uterine Doppler studies at 18-20 weeks.

Third Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ As indicated by the clinical situation, perform laboratory testing, serial ultrasonography (for fetal growth and amniotic fluid assessment), and umbilical artery Doppler with a nonstress test and/or biophysical profile.

▸ Hospitalize for severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia.

Post Partum

▸ Counsel patient about an increased risk for cardiovascular disease and ischemic stroke.

▸ Encourage close follow-up and prevention.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Risk Factors for Preeclampsia

The magnitude of risk depends on the number of factors, which include the following:

▸ Multifetal gestation.

▸ Unexplained fetal growth restriction.

▸ Gestational hypertension.

▸ Hydrops/hydropic degeneration of placenta (triploidy, trisomy 13).

▸ Urinary-tract and periodontal infections.

▸ Biophysical and biochemical markers.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Despite several decades of extensive research into its pathogenesis, preeclampsia continues to be a syndrome of unknown etiology.

Several theories on the mechanisms leading to preeclampsia have been proposed, all based on numerous pathophysiological abnormalities reported in association with the heterogeneous disorder.

These theories, which have been developed largely during the past 2 decades, involve abnormalities such as impaired trophoblast differentiation and invasion, placental and endothelial dysfunction, immune maladaptation to paternal antigens, an exaggerated systemic inflammatory response, and a state of imbalance between proangiogenic and antiangiogenic factors.

As evidence for these theories has unfolded, investigators have identified numerous risk factors for preeclampsia. Most of them are preexisting risk factors that can be identified either before a patient becomes pregnant or early in the pregnancy. (See box below.)

The disorder's pathogenesis can vary in women with different risk factors or different times of onset. In women with previous preeclampsia, for example, the risk for developing recurrent preeclampsia varies depending on the underlying mechanism and the outcome in the previous pregnancy.

What this means is that even as investigators work to improve our understanding of the disorder, we as clinicians have an immediate opportunity—and responsibility—to identify patients who are at risk for preeclampsia, or recurrent preeclampsia, during preconception counseling or early in gestation.

We can then work with at-risk patients to optimize their health before conception and to carefully manage maternal and fetal well-being during pregnancy.

Women with a history of previous preeclampsia—even those who suffered serious adverse outcomes—should be counseled about their risks and reassured about our ability to optimize outcomes through vigilant monitoring, early detection of complications, and timely delivery.

And in an effort to improve their long-term health, these women should also be counseled about an increased risk for cardiovascular disease and ischemic stroke later in their lives.

Common Scenarios

A healthy 22-year-old woman with an ideal body weight and no preexisting medical risk factors who plans to become pregnant for the first time.

This patient's risk for preeclampsia is low (only 1%-2%). If preeclampsia occurs, it is likely to be mild, with an onset near term or intrapartum, and with generally good outcomes.

Nevertheless, it is important to inquire about any family history of preeclampsia or cardiovascular disease in this type of patient, and to be aware that women who themselves were born small for gestational age have an increased risk for preeclampsia, as does any woman whose husband or partner fathered a preeclamptic pregnancy in another woman.

Certain changes and events can also occur during pregnancy that will increase her risk. If, during antenatal care, ultrasound reveals multifetal gestation or unexplained fetal growth restriction, for instance, her risk of preeclampsia will increase substantially. (See box, page 9, top right.)

Likewise, if she develops gestational hypertension, her risk will increase to 25%-50% based on gestational age at the time the hypertension developed.

Several recently published studies have reported an association between maternal infections and an increased risk of preeclampsia as well. (Infections probably increase a maternal inflammatory response that already is engendered by the pregnancy itself.)

A systematic review published in 2006 found that the odds ratio for preeclampsia was 1.57 in women with urinary tract infections, and 1.76 in women with periodontal disease (N. Engl. J. Med. 2006;355:992-1005).

Unfortunately, the various biomarkers that have been proposed to predict which women are likely to develop preeclampsia—from serum placental growth factor to asymmetric dimethylarginine—have not been shown to be reliable and are not predictive or specific enough for use in clinical practice.

Likewise, supplementation with fish oil, vitamin E, vitamin C, low-dose aspirin, or calcium is not recommended for the prevention of preeclampsia in the young woman with no risk factors.

A 42-year-old who is trying to become pregnant for the first time.

This patient's older age is itself a risk factor for preeclampsia. An older age also often means more body weight and a higher likelihood of chronic hypertension or diabetes, as well as an increased likelihood that donated gametes were used, all of which can significantly increase risk.

As in the case of the younger patient, risk evaluation and management should begin before conception. Family history, personal birth history, and the history of the patient's husband or partner should be explored.

And because a high body mass index is a proven risk factor—as is insulin resistance, which is often linked with obesity—patients who are overweight or obese should be encouraged to lose weight and achieve a healthy BMI.

The risks associated with preexisting medical conditions like hypertension and diabetes vary depending on the conditions' severity.

Studies show, for instance, that women with mild hypertension before conception or early in pregnancy have a 15% rate of preeclampsia, whereas women with severe prepregnancy hypertension have a nearly 50% risk.

In all cases, women with chronic hypertension or diabetes should have their blood pressure and glucose levels optimized before conception, and then controlled throughout their pregnancy.

When assisted reproductive technology is planned, a discussion about the increased risk for preeclampsia that is caused by donated gametes is important, because donor insemination or the use of donated oocytes affects the maternal-fetal immune interaction and increases the risk of preeclampsia to as much as 35%.

Because multifetal gestation is more common with ART than with natural birth and is another risk factor for preeclampsia, this patient's overall risk can also be minimized by reducing the number of transferred embryos and by avoiding hyperstimulation when ovulation induction is required.

Just as in the case of the younger woman, unfortunately, we have little if anything else to offer this patient for the prevention of preeclampsia.

These women can be offered calcium, however. A recent review by the Food and Drug Administration concluded that any benefit with respect to preeclampsia is inconclusive and “unlikely” (Nutr. Rev. 2007;65:78-87).

However, in a 2007 Cochrane review of 12 clinical studies, calcium supplementation was associated with a reduction in the rate of preeclampsia, particularly in populations at high risk and in those with diets deficient in calcium (BJOG 2007;114:933-43).

Management should include a baseline metabolic profile and complete blood count, as well as baseline urinalysis; this information can be helpful if later laboratory studies are needed to assess the function of organ systems likely to be affected by preeclampsia.

Serial ultrasonography as well as uterine Doppler studies at 18-20 weeks should also be employed. The Doppler studies are a useful tool for assessing the velocity of the uterine artery blood flow.

An increased resistance index and/or the presence of uterine artery diastolic notching suggests an increased risk of preeclampsia (as much as a sixfold increased risk) and the need for more vigilant monitoring and care.

A woman who developed severe preeclampsia at 26 weeks' gestation in her first pregnancy. She wants a child but is afraid—terribly and understandably frightened—of a second pregnancy because her first baby was born prematurely and died after about 100 days in the NICU.

We can and should reassure this patient that her loss does not mean she should forego becoming pregnant again, and that with proper monitoring, she has a significant chance of having a healthy baby.

A woman's risk of preeclampsia recurrence will depend on whether or not she has any preexisting risk factors, as well as the gestational age at the time of onset of preeclampsia in her first pregnancy.

The reported rate of recurrent preeclampsia ranges from 11.5% to 65%, with the highest rates being reported in women whose previous preeclampsia occurred in the second trimester. This patient's risk of recurrent preeclampsia is about 50%.

In general, recurrent preeclampsia is more likely to be severe and to develop preterm than is first-time preeclampsia. We can reassure this patient, however, that an early onset of preeclampsia in the first pregnancy does not necessarily mean that the disorder will have an early onset in the second pregnancy.

In a study published in 1991, among women with previous preeclampsia in the second trimester, preeclampsia recurred in the second trimester in 21%, at 28-36 weeks in 21%, and at term in 23% (Am. J. Obstet. Gynecol. 1991;165:1408-12).

Women with a history of eclampsia have a rate of recurrence of 1%-2% and a rate of subsequent preeclampsia of 22%-35%. Women with a history of HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome have a rate of preeclampsia in subsequent pregnancies of 16%-52% and, according to the most reliable data, a rate of recurrent HELLP syndrome of less than 5%.

Management for this patient ideally begins before conception, with an extensive evaluation and an in-depth history to uncover preexisting risk factors and/or medical conditions associated with the disorder.

This will allow proper counseling about the magnitude of risk for preeclampsia recurrence, and will guide you as you manage the pregnancy. (See box, bottom left.)

Knowing when she developed preeclampsia is important, as are details about maternal complications such as HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, pulmonary edema, or renal failure, for instance; about fetal complications, such as fetal growth restriction; and about previous laboratory test results, as well as placental pathology.

The status of any comorbidities, such as high BMI or high blood pressure, should be optimized before conception, and vigilant monitoring—including early and serial ultrasonography, uterine Doppler assessment at 18-20 weeks, and laboratory testing as indicated—should be instituted to minimize and manage her risk.

By detecting complications early and monitoring for signs and symptoms of preeclampsia—and then hospitalizing her if you detect severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia—you can ensure optimal outcomes.

This patient will probably want to know about the value of various biomarkers and supplements, such as fish oil and vitamins C and E, and again, we need to explain that the best studies have shown minimal to no benefit and do not support their use.

The three large randomized trials looking at vitamin E supplementation, for example, showed no effect on the rate of preeclampsia, its severity, or the rate of adverse neonatal outcomes.

None of the randomized trials on calcium supplementation included women with a previous history of preeclampsia, so the benefit for this indication remains unclear. Nevertheless, because calcium is beneficial for any pregnancy, we recommend it.

The greatest benefits of low-dose aspirin may come for this patient. A recent meta-analysis of 31 randomized trials found a 14% reduction in recurrent preeclampsia—higher than that seen for first-time preeclampsia (Lancet 2007;369:1791-8). Low-dose aspirin has also proved to be safe. We recommend 81 mg daily beginning at 12 weeks' gestation, and suggest discontinuing aspirin with the development of preeclampsia.

If the patient has documented evidence of antiphospholipid antibody syndrome, she should receive prophylactic-dose heparin in addition to low-dose aspirin once fetal viability is confirmed.

A woman who had late-occurring mild preeclampsia in her first pregnancy, and is planning a second child.

This patient experienced the most common presentation of preeclampsia, and fortunately has a fairly low risk for recurrence (about 10%). Chances are also likely that if preeclampsia recurs, it will recur at term.

This risk can be minimized and a good outcome ensured by following the same approach to history taking, counseling, and optimizing health before conception, as well as careful monitoring during pregnancy to detect complications early.

Risks Later in Life

Today, counseling women with a history of preeclampsia involves more than assessing and minimizing risks for recurrence of the disorder. It also involves discussing the now-substantial body of literature that suggests that women whose pregnancies are complicated by preeclampsia and/or fetal growth restriction have an increased risk for future cardiovascular disease and ischemic stroke.

These women require close follow-up after their pregnancies so that their long-term risks can be reduced or avoided through the use of preventive strategies and approaches to care.

Preeclampsia and fetal growth restriction are both vascular-related pregnancy complications, and they share similar risk factors and pathophysiological abnormalities, such as endothelial dysfunction.

It's unclear exactly what mechanisms account for the relationship among these complications and the increased risk of subsequent cardiovascular disease, but it increasingly seems likely that these women have a predisposition to vascular and metabolic disease: a constitutional risk.

Epidemiologic and case-control studies published in the last 10 years—many of them in the nonobstetric literature—have evaluated the associations, and last year a systematic review and meta-analysis of these studies reported a relative risk for chronic hypertension of 3.7 after approximately 14 years of average follow-up, a relative risk of 2.16 for ischemic heart disease after about 11 years of follow-up, and a relative risk of 1.8 for ischemic stroke after about 10 years (BMJ 2007;335:974-85).

In addition, overall mortality after preeclampsia was increased by a relative risk of approximately 1.5 after 14.5 years of follow-up.

In a recently published intergenerational case-control study, Dutch investigators looked at 106 women whose pregnancies were complicated by preeclampsia or fetal growth restriction, a control group of 106 women with normal pregnancies, and each woman's mother and father.

They found significant intergenerational similarities in cardiovascular risk profiles between the women after preeclampsia or fetal growth restriction and their parents, such as higher fasting glucose levels that could not be explained by differences in BMI.

Intergenerational similarities were also found for hypertension, waist circumference, and metabolic syndrome (Hypertension 2008;51:1034-41).

ELSEVIER GLOBAL MEDICAL NEWS

Preeclampsia, Part 3

The exact incidence of preeclampsia is unknown, but in its mild form it is estimated to affect up to 10% of all pregnancies. Indeed, it is one of the most common complications of pregnancy. In a smaller number of cases (just under 1% of pregnancies), the disorder develops as severe preeclampsia.

In the past two Master Class installments on preeclampsia, we have discussed how the disorder presents in various ways, afflicting women of different age groups, of varying parity, and with associated medical complications or the lack thereof.

We have also discussed appropriate evaluation and management protocols. The spectrum of disease is such that it spans the very mild (requiring modest intervention) to the very severe (requiring immediate and aggressive intervention strategies). As we saw in the last installment, it is important to view preeclampsia as a multifaceted disease continuum in which designations of “mild” and “severe” are not necessarily fixed.

The variable presentation of the disorder—and the fact that it cannot be precisely predicted or prevented—may in itself be challenging to the practitioner, as he or she counsels patients who are contemplating pregnancies and may be at risk for preeclampsia.

There are certain predisposing medical and sociodemographic factors, however, that are clearly important and that can be useful if they are integrated into an evaluation and management algorithm. Integrating our knowledge of risk factors allows for the most appropriate counseling to be delivered, and the most appropriate management plan to be developed, on a case-by-case basis.

I have invited Dr. Baha Sibai to once again address the topic of preeclampsia in this third and final installment of our series on the disorder. Dr. Sibai is professor of obstetrics and gynecology at the University of Cincinnati and an international expert on preeclampsia and eclampsia, as well as a leader in both clinical care and research in this area.

In this case, we've taken a different approach to presenting the material. We think our case-by-case format will be practical and applicable to the practitioner who is counseling a number of patients who present with varying histories and risk factors.

How to Manage Recurrence Risk

Preconception

▸ Identify risk factors.

▸ Review outcome of previous pregnancy.

▸ Optimize maternal health.

First Trimester

▸ Perform ultrasonography for dating and assessing fetal number.

▸ Order baseline metabolic profile and complete blood count.

▸ Perform baseline urinalysis.

▸ Offer first-trimester combined screening.

▸ If antiphospholipid syndrome is documented, start low-dose aspirin and heparin. Otherwise, offer low-dose aspirin therapy at 12 weeks' gestation.

Second Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ Perform ultrasonography at 18-22 weeks' gestation for fetal anomaly evaluation and to rule out molar gestation.

▸ Perform uterine Doppler studies at 18-20 weeks.

Third Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ As indicated by the clinical situation, perform laboratory testing, serial ultrasonography (for fetal growth and amniotic fluid assessment), and umbilical artery Doppler with a nonstress test and/or biophysical profile.

▸ Hospitalize for severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia.

Post Partum

▸ Counsel patient about an increased risk for cardiovascular disease and ischemic stroke.

▸ Encourage close follow-up and prevention.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Risk Factors for Preeclampsia

The magnitude of risk depends on the number of factors, which include the following:

▸ Multifetal gestation.

▸ Unexplained fetal growth restriction.

▸ Gestational hypertension.

▸ Hydrops/hydropic degeneration of placenta (triploidy, trisomy 13).

▸ Urinary-tract and periodontal infections.

▸ Biophysical and biochemical markers.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Despite several decades of extensive research into its pathogenesis, preeclampsia continues to be a syndrome of unknown etiology.

Several theories on the mechanisms leading to preeclampsia have been proposed, all based on numerous pathophysiological abnormalities reported in association with the heterogeneous disorder.

These theories, which have been developed largely during the past 2 decades, involve abnormalities such as impaired trophoblast differentiation and invasion, placental and endothelial dysfunction, immune maladaptation to paternal antigens, an exaggerated systemic inflammatory response, and a state of imbalance between proangiogenic and antiangiogenic factors.

As evidence for these theories has unfolded, investigators have identified numerous risk factors for preeclampsia. Most of them are preexisting risk factors that can be identified either before a patient becomes pregnant or early in the pregnancy. (See box below.)

The disorder's pathogenesis can vary in women with different risk factors or different times of onset. In women with previous preeclampsia, for example, the risk for developing recurrent preeclampsia varies depending on the underlying mechanism and the outcome in the previous pregnancy.

What this means is that even as investigators work to improve our understanding of the disorder, we as clinicians have an immediate opportunity—and responsibility—to identify patients who are at risk for preeclampsia, or recurrent preeclampsia, during preconception counseling or early in gestation.

We can then work with at-risk patients to optimize their health before conception and to carefully manage maternal and fetal well-being during pregnancy.

Women with a history of previous preeclampsia—even those who suffered serious adverse outcomes—should be counseled about their risks and reassured about our ability to optimize outcomes through vigilant monitoring, early detection of complications, and timely delivery.

And in an effort to improve their long-term health, these women should also be counseled about an increased risk for cardiovascular disease and ischemic stroke later in their lives.

Common Scenarios

A healthy 22-year-old woman with an ideal body weight and no preexisting medical risk factors who plans to become pregnant for the first time.

This patient's risk for preeclampsia is low (only 1%-2%). If preeclampsia occurs, it is likely to be mild, with an onset near term or intrapartum, and with generally good outcomes.

Nevertheless, it is important to inquire about any family history of preeclampsia or cardiovascular disease in this type of patient, and to be aware that women who themselves were born small for gestational age have an increased risk for preeclampsia, as does any woman whose husband or partner fathered a preeclamptic pregnancy in another woman.

Certain changes and events can also occur during pregnancy that will increase her risk. If, during antenatal care, ultrasound reveals multifetal gestation or unexplained fetal growth restriction, for instance, her risk of preeclampsia will increase substantially. (See box, page 9, top right.)

Likewise, if she develops gestational hypertension, her risk will increase to 25%-50% based on gestational age at the time the hypertension developed.

Several recently published studies have reported an association between maternal infections and an increased risk of preeclampsia as well. (Infections probably increase a maternal inflammatory response that already is engendered by the pregnancy itself.)

A systematic review published in 2006 found that the odds ratio for preeclampsia was 1.57 in women with urinary tract infections, and 1.76 in women with periodontal disease (N. Engl. J. Med. 2006;355:992-1005).

Unfortunately, the various biomarkers that have been proposed to predict which women are likely to develop preeclampsia—from serum placental growth factor to asymmetric dimethylarginine—have not been shown to be reliable and are not predictive or specific enough for use in clinical practice.

Likewise, supplementation with fish oil, vitamin E, vitamin C, low-dose aspirin, or calcium is not recommended for the prevention of preeclampsia in the young woman with no risk factors.

A 42-year-old who is trying to become pregnant for the first time.

This patient's older age is itself a risk factor for preeclampsia. An older age also often means more body weight and a higher likelihood of chronic hypertension or diabetes, as well as an increased likelihood that donated gametes were used, all of which can significantly increase risk.

As in the case of the younger patient, risk evaluation and management should begin before conception. Family history, personal birth history, and the history of the patient's husband or partner should be explored.

And because a high body mass index is a proven risk factor—as is insulin resistance, which is often linked with obesity—patients who are overweight or obese should be encouraged to lose weight and achieve a healthy BMI.

The risks associated with preexisting medical conditions like hypertension and diabetes vary depending on the conditions' severity.

Studies show, for instance, that women with mild hypertension before conception or early in pregnancy have a 15% rate of preeclampsia, whereas women with severe prepregnancy hypertension have a nearly 50% risk.

In all cases, women with chronic hypertension or diabetes should have their blood pressure and glucose levels optimized before conception, and then controlled throughout their pregnancy.

When assisted reproductive technology is planned, a discussion about the increased risk for preeclampsia that is caused by donated gametes is important, because donor insemination or the use of donated oocytes affects the maternal-fetal immune interaction and increases the risk of preeclampsia to as much as 35%.

Because multifetal gestation is more common with ART than with natural birth and is another risk factor for preeclampsia, this patient's overall risk can also be minimized by reducing the number of transferred embryos and by avoiding hyperstimulation when ovulation induction is required.

Just as in the case of the younger woman, unfortunately, we have little if anything else to offer this patient for the prevention of preeclampsia.

These women can be offered calcium, however. A recent review by the Food and Drug Administration concluded that any benefit with respect to preeclampsia is inconclusive and “unlikely” (Nutr. Rev. 2007;65:78-87).

However, in a 2007 Cochrane review of 12 clinical studies, calcium supplementation was associated with a reduction in the rate of preeclampsia, particularly in populations at high risk and in those with diets deficient in calcium (BJOG 2007;114:933-43).

Management should include a baseline metabolic profile and complete blood count, as well as baseline urinalysis; this information can be helpful if later laboratory studies are needed to assess the function of organ systems likely to be affected by preeclampsia.

Serial ultrasonography as well as uterine Doppler studies at 18-20 weeks should also be employed. The Doppler studies are a useful tool for assessing the velocity of the uterine artery blood flow.

An increased resistance index and/or the presence of uterine artery diastolic notching suggests an increased risk of preeclampsia (as much as a sixfold increased risk) and the need for more vigilant monitoring and care.

A woman who developed severe preeclampsia at 26 weeks' gestation in her first pregnancy. She wants a child but is afraid—terribly and understandably frightened—of a second pregnancy because her first baby was born prematurely and died after about 100 days in the NICU.

We can and should reassure this patient that her loss does not mean she should forego becoming pregnant again, and that with proper monitoring, she has a significant chance of having a healthy baby.

A woman's risk of preeclampsia recurrence will depend on whether or not she has any preexisting risk factors, as well as the gestational age at the time of onset of preeclampsia in her first pregnancy.

The reported rate of recurrent preeclampsia ranges from 11.5% to 65%, with the highest rates being reported in women whose previous preeclampsia occurred in the second trimester. This patient's risk of recurrent preeclampsia is about 50%.

In general, recurrent preeclampsia is more likely to be severe and to develop preterm than is first-time preeclampsia. We can reassure this patient, however, that an early onset of preeclampsia in the first pregnancy does not necessarily mean that the disorder will have an early onset in the second pregnancy.

In a study published in 1991, among women with previous preeclampsia in the second trimester, preeclampsia recurred in the second trimester in 21%, at 28-36 weeks in 21%, and at term in 23% (Am. J. Obstet. Gynecol. 1991;165:1408-12).

Women with a history of eclampsia have a rate of recurrence of 1%-2% and a rate of subsequent preeclampsia of 22%-35%. Women with a history of HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome have a rate of preeclampsia in subsequent pregnancies of 16%-52% and, according to the most reliable data, a rate of recurrent HELLP syndrome of less than 5%.

Management for this patient ideally begins before conception, with an extensive evaluation and an in-depth history to uncover preexisting risk factors and/or medical conditions associated with the disorder.

This will allow proper counseling about the magnitude of risk for preeclampsia recurrence, and will guide you as you manage the pregnancy. (See box, bottom left.)

Knowing when she developed preeclampsia is important, as are details about maternal complications such as HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, pulmonary edema, or renal failure, for instance; about fetal complications, such as fetal growth restriction; and about previous laboratory test results, as well as placental pathology.

The status of any comorbidities, such as high BMI or high blood pressure, should be optimized before conception, and vigilant monitoring—including early and serial ultrasonography, uterine Doppler assessment at 18-20 weeks, and laboratory testing as indicated—should be instituted to minimize and manage her risk.

By detecting complications early and monitoring for signs and symptoms of preeclampsia—and then hospitalizing her if you detect severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia—you can ensure optimal outcomes.

This patient will probably want to know about the value of various biomarkers and supplements, such as fish oil and vitamins C and E, and again, we need to explain that the best studies have shown minimal to no benefit and do not support their use.

The three large randomized trials looking at vitamin E supplementation, for example, showed no effect on the rate of preeclampsia, its severity, or the rate of adverse neonatal outcomes.

None of the randomized trials on calcium supplementation included women with a previous history of preeclampsia, so the benefit for this indication remains unclear. Nevertheless, because calcium is beneficial for any pregnancy, we recommend it.

The greatest benefits of low-dose aspirin may come for this patient. A recent meta-analysis of 31 randomized trials found a 14% reduction in recurrent preeclampsia—higher than that seen for first-time preeclampsia (Lancet 2007;369:1791-8). Low-dose aspirin has also proved to be safe. We recommend 81 mg daily beginning at 12 weeks' gestation, and suggest discontinuing aspirin with the development of preeclampsia.

If the patient has documented evidence of antiphospholipid antibody syndrome, she should receive prophylactic-dose heparin in addition to low-dose aspirin once fetal viability is confirmed.

A woman who had late-occurring mild preeclampsia in her first pregnancy, and is planning a second child.

This patient experienced the most common presentation of preeclampsia, and fortunately has a fairly low risk for recurrence (about 10%). Chances are also likely that if preeclampsia recurs, it will recur at term.

This risk can be minimized and a good outcome ensured by following the same approach to history taking, counseling, and optimizing health before conception, as well as careful monitoring during pregnancy to detect complications early.

Risks Later in Life

Today, counseling women with a history of preeclampsia involves more than assessing and minimizing risks for recurrence of the disorder. It also involves discussing the now-substantial body of literature that suggests that women whose pregnancies are complicated by preeclampsia and/or fetal growth restriction have an increased risk for future cardiovascular disease and ischemic stroke.

These women require close follow-up after their pregnancies so that their long-term risks can be reduced or avoided through the use of preventive strategies and approaches to care.

Preeclampsia and fetal growth restriction are both vascular-related pregnancy complications, and they share similar risk factors and pathophysiological abnormalities, such as endothelial dysfunction.

It's unclear exactly what mechanisms account for the relationship among these complications and the increased risk of subsequent cardiovascular disease, but it increasingly seems likely that these women have a predisposition to vascular and metabolic disease: a constitutional risk.

Epidemiologic and case-control studies published in the last 10 years—many of them in the nonobstetric literature—have evaluated the associations, and last year a systematic review and meta-analysis of these studies reported a relative risk for chronic hypertension of 3.7 after approximately 14 years of average follow-up, a relative risk of 2.16 for ischemic heart disease after about 11 years of follow-up, and a relative risk of 1.8 for ischemic stroke after about 10 years (BMJ 2007;335:974-85).

In addition, overall mortality after preeclampsia was increased by a relative risk of approximately 1.5 after 14.5 years of follow-up.

In a recently published intergenerational case-control study, Dutch investigators looked at 106 women whose pregnancies were complicated by preeclampsia or fetal growth restriction, a control group of 106 women with normal pregnancies, and each woman's mother and father.

They found significant intergenerational similarities in cardiovascular risk profiles between the women after preeclampsia or fetal growth restriction and their parents, such as higher fasting glucose levels that could not be explained by differences in BMI.

Intergenerational similarities were also found for hypertension, waist circumference, and metabolic syndrome (Hypertension 2008;51:1034-41).

ELSEVIER GLOBAL MEDICAL NEWS

Preeclampsia, Part 3

The exact incidence of preeclampsia is unknown, but in its mild form it is estimated to affect up to 10% of all pregnancies. Indeed, it is one of the most common complications of pregnancy. In a smaller number of cases (just under 1% of pregnancies), the disorder develops as severe preeclampsia.

In the past two Master Class installments on preeclampsia, we have discussed how the disorder presents in various ways, afflicting women of different age groups, of varying parity, and with associated medical complications or the lack thereof.

We have also discussed appropriate evaluation and management protocols. The spectrum of disease is such that it spans the very mild (requiring modest intervention) to the very severe (requiring immediate and aggressive intervention strategies). As we saw in the last installment, it is important to view preeclampsia as a multifaceted disease continuum in which designations of “mild” and “severe” are not necessarily fixed.

The variable presentation of the disorder—and the fact that it cannot be precisely predicted or prevented—may in itself be challenging to the practitioner, as he or she counsels patients who are contemplating pregnancies and may be at risk for preeclampsia.

There are certain predisposing medical and sociodemographic factors, however, that are clearly important and that can be useful if they are integrated into an evaluation and management algorithm. Integrating our knowledge of risk factors allows for the most appropriate counseling to be delivered, and the most appropriate management plan to be developed, on a case-by-case basis.

I have invited Dr. Baha Sibai to once again address the topic of preeclampsia in this third and final installment of our series on the disorder. Dr. Sibai is professor of obstetrics and gynecology at the University of Cincinnati and an international expert on preeclampsia and eclampsia, as well as a leader in both clinical care and research in this area.

In this case, we've taken a different approach to presenting the material. We think our case-by-case format will be practical and applicable to the practitioner who is counseling a number of patients who present with varying histories and risk factors.

How to Manage Recurrence Risk

Preconception

▸ Identify risk factors.

▸ Review outcome of previous pregnancy.

▸ Optimize maternal health.

First Trimester

▸ Perform ultrasonography for dating and assessing fetal number.

▸ Order baseline metabolic profile and complete blood count.

▸ Perform baseline urinalysis.

▸ Offer first-trimester combined screening.

▸ If antiphospholipid syndrome is documented, start low-dose aspirin and heparin. Otherwise, offer low-dose aspirin therapy at 12 weeks' gestation.

Second Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ Perform ultrasonography at 18-22 weeks' gestation for fetal anomaly evaluation and to rule out molar gestation.

▸ Perform uterine Doppler studies at 18-20 weeks.

Third Trimester

▸ Monitor for signs and symptoms of preeclampsia.

▸ As indicated by the clinical situation, perform laboratory testing, serial ultrasonography (for fetal growth and amniotic fluid assessment), and umbilical artery Doppler with a nonstress test and/or biophysical profile.

▸ Hospitalize for severe gestational hypertension, fetal growth restriction, or recurrent preeclampsia.

Post Partum

▸ Counsel patient about an increased risk for cardiovascular disease and ischemic stroke.

▸ Encourage close follow-up and prevention.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Risk Factors for Preeclampsia

The magnitude of risk depends on the number of factors, which include the following:

▸ Multifetal gestation.

▸ Unexplained fetal growth restriction.

▸ Gestational hypertension.

▸ Hydrops/hydropic degeneration of placenta (triploidy, trisomy 13).

▸ Urinary-tract and periodontal infections.

▸ Biophysical and biochemical markers.

Source: Adapted from Obstet. Gynecol. 2008;112:359-72

Some surgeons perform the procedure laparoscopically in an effort to decrease morbidity and recovery time, with some success. Overall, however, a laparoscopic approach has not been widely adopted because of the complex suturing and dissection involved, and the subsequently significant learning curve.

Robotic sacrocolpopexy is a new addition to our armamentarium and is an exciting option for me and other surgeons because it combines the advantages of open sacrocolpopexy with the decreased morbidity of laparoscopy.

A robotic approach to the tried-and-true abdominal sacrocolpopexy takes full advantage of all that robotic surgery offers. Instrument articulation, three-dimensional vision, tremor reduction, and improved ergonomics for the surgeon all make managing the mesh and intracorporeal suturing—as well as dissecting in the rectovaginal and presacral spaces—so much easier than would be the case with a standard laparoscopic approach.

Overall, sacrocolpopexy performed with the da Vinci surgical system—the only Food and Drug Administration-approved robotic device for use in gynecologic surgery—offers better access to the pelvis, compared with both the open and laparoscopic approaches.

We can truly replicate what we do in an open approach, but with less postoperative pain, less blood loss and scarring, and faster recovery. Robotic sacrocolpopexy can also be combined with total or supracervical hysterectomy for uterine prolapse.

Outcomes data are emerging. At the American Urogynecologic Society annual meeting last month, we presented our initial short-term data comparing robotic with traditional abdominal sacrocolpopexy for the treatment of both uterine and vaginal vault prolapse.

Postoperatively, based on a 6-week POPQ (Pelvic Organ Prolapse Quantification) examination, there was a similar degree of pelvic organ support in the 73 patients who underwent robotic surgery and the 105 patients who underwent traditional surgery. The length of hospital stay was significantly shorter with the robotic approach (1.3 days vs. 2.7 days), and estimated blood loss was significantly lower (103 mL vs. 255 mL).

The operative time for the colpopexy and all other procedures, including hysterectomy and slings, was significantly longer in the robotic group (328 vs. 225 minutes). This time is expected to decrease, however, as all members of the surgical team, including fellows, residents, and surgical staff, progress through the learning curve.

Patient Selection and Positioning

I now offer the procedure to any patient to whom I would recommend a sacrocolpopexy. In the initial stages of adopting a robotic approach, however, it makes sense to be more selective and to perform relatively straightforward surgeries. This means starting with patients who are relatively thin (with body mass indices less than 30 kg/m

Initial patients should also have a reasonably sized uterus (if present) and few comorbidities. Pulmonary morbidity (emphysema or chronic obstructive pulmonary disease, for instance) is a relative contraindication, especially for initial cases, because these patients may not tolerate the Trendelenburg position, which is required for the surgery.

In addition, although robotic sacrocolpopexy can be used for uterine prolapse, I recommend starting with patients who have vaginal vault prolapse so that the surgeon can focus on a single robotic procedure. As their experience grows, surgeons can easily perform a combined robotic hysterectomy with sacrocolpopexy for the treatment of uterine prolapse. I primarily perform a supracervical hysterectomy in combination with a sacrocolpopexy in an attempt to reduce the risk of mesh erosion.

When the patient is positioned at the start of the surgery, her arms and shoulders and all “pressure points” should be well padded with foam, but I do not find a need for shoulder pads. I typically use an extra-large vacuum bean bag to keep the patient firmly in place while she is in the moderate to steep Trendelenburg position, but the use of a gel pad placed between the patient and the bed is an alternative approach to keep the patient from sliding cephalad during the surgery.

Port Placement, Setup, and Preparation

For robotic sacrocolpopexy, five trocar sites are used with a four-arm robotic system: three for operative robotic arms, one for the camera, and one to be used as the assistant's port for suction and irrigation, assistance with traction/countertraction, and the introduction of suture and mesh. (The bedside assistant is also helpful for instrument swaps, during uterine morcellation, and for any trocar depth repositioning that is necessary.)

Initially, we tried several different port locations. We have found that a “W-like” configuration for our port placement works well. We place the camera trocar at the umbilicus to accommodate the endoscope and the camera arm. This represents the middle of our “W.”

We then place two robotic ports at the two inferior apices of the “W.” The lateral ends of the “W” are each located about 2 cm inferior to the level of the umbilicus. The right lateral port is the assistant's port, which is used to introduce mesh, suture, and the like. The left lateral port is for the third robotic operative arm and is particularly helpful in moving the sigmoid laterally to expose the sacrum.

Using this configuration, we have reduced any competition between the two left robotic arms while we operate either in the pelvis or at the sacrum.

Some surgeons place the camera port higher (above the umbilicus), but I do not care for this placement because it can partially impede the view over the sacral promontory. (Placement of the camera port above the umbilicus is necessary for enlarged uteri, however.) After initial entry, a 0-degree scope should be used to place the other ports.

It is important to maintain at least 10 cm between robotic ports, and at least 6 cm between the robotic port and the assistant's port to reduce external collision of the robotic instrument arms.

Before docking the robotic arms of the patientside cart and placing the various EndoWrist instruments, I laparoscopically remove any small-bowel adhesions or other abdominal wall adhesions. This way, I have the tactile sensation that robotics does not provide. I then retract the sigmoid and move the small bowel out of the pelvis to expose the sacrum and the sacral promontory.

At this point and still prior to docking, it is also important to identify the ureters, the sacral promontory, the midline with the sigmoid retracted, the middle sacral vessels, and the iliac vessels. The left common iliac vessels, particularly the vein, can occasionally be identified crossing very close to the sacral promontory.

The operating table should be lowered and the patientside cart should be positioned as high as possible to clear the patient's legs, and then—after all overhead lights and equipment are moved to the side—the cart can be rolled into position between the patient's legs and aligned in a straight line with the camera arm and umbilical camera port. Docking can then be easily accomplished.

Open communication with the anesthesiology team is important. Robotic sacrocolpopexy is associated with significantly less blood loss (typically less than 25 mL) and less insensible loss than is open sacrocolpopexy. Therefore intravenous fluids should generally be limited to a liter or less.

Surgical Steps

If the patient has uterine prolapse, this can be addressed first with a supracervical or total hysterectomy. I prefer supracervical hysterectomies, assuming that the patient's Pap smears have been normal, in an attempt to reduce the risk of mesh erosion. After the hysterectomy, I place the uterus along the left lateral gutter for morcellation at the end of the procedure and after the system is undocked.

With either type of hysterectomy, the use of a colpotomy ring—either a KOH cup or a VCARE device—works nicely. We find this helpful in manipulating the uterus and defining the cervical-vaginal junction, even during supracervical hysterectomies, because it helps in the dissection of the bladder flap.

After the bladder flap is dissected off the anterior vaginal wall (close to the anterior vaginal wall to avoid cystotomy and to identify the avascular plane), the rectovaginal septum is developed. Approximately 6-8 cm of anterior vaginal wall are exposed.

The placement of round, 31- to 33-mm EEA (end-to-end anastomosis) sizers in the vagina to manipulate the vaginal apex helps with the bladder flap dissection, which can be challenging in patients who have had a previous cesarean section, hysterectomy, or vaginal reconstructive procedure—especially those performed with vaginally placed mesh. Occasionally, the bladder is found densely adherent over the apex of the vagina and adherent to the proximal posterior vaginal wall.

I frequently have an additional, smaller (29-mm) sizer placed in the rectum to help clearly identify the rectovaginal septum and facilitate the dissection.

During the rectovaginal dissection, the vaginal EEA sizer should be oriented anteriorly to better expose the posterior vaginal wall. Between 6 cm and 10 cm of the posterior vaginal wall should be dissected, while the camera is kept at midline and oriented to the horizon.

At this point, I frequently switch to a 30-degree down scope to develop the presacral space. This enables me to see over the sacral promontory and enhances my view. Depending on the configuration of the sacrum, it is possible to complete the surgery with a 0-degree scope. However, the view of the presacral space is generally significantly improved with the 30-degree down scope.

The sigmoid is retracted laterally by the third operative arm, and the peritoneum is lifted up, or tented, over the sacrum in the midline to avoid injury to a vessel. Our goal is to identify the anterior longitudinal ligament, and this area can be fairly vascular. Once the anterior longitudinal ligament is identified, the presacral peritoneal dissection can be extended inferiorly to the vagina.

I use a Y-shaped polypropylene mesh (AMS) and introduce it, trimmed to the appropriate width and length, in the proper anatomical orientation. I place the distal and lateral sutures on the anterior vaginal wall first, and then place several (four to eight) additional sutures to secure the mesh to the anterior vaginal wall. To suture, I use a Mega needle driver in the left hand and a SutureCut needle driver in the right. The SutureCut needle driver is similar to the Mega needle driver, but it also has a cutting mechanism that provides enhanced autonomy to the console surgeon and makes suturing more efficient overall.

Using the third operative robotic arm, I then roll the sacral end of the mesh and lift it anteriorly, which allows the posterior mesh to drape nicely over the posterior vaginal wall. The longer posterior mesh can then be easily sutured to the posterior wall of the vagina. For the posterior vaginal-wall mesh attachment, I usually start at the vaginal apex and work my way inferiorly. Throughout the surgery, I use permanent sutures of CV-2 Gore-Tex.

I then adjust the mesh tension, ensuring that it will be attached to the sacrum without undue tension and with equal distribution of support to the anterior and posterior of the vagina. Once this is determined, the excess mesh is trimmed.

I typically place three sacral sutures to secure the mesh to the sacrum. I place the inferiormost suture first, using a slip (or sliding) knot. This is a one-way knot that allows the mesh to be easily attached to the sacrum without the need for an assistant to hold the mesh against the sacrum while the suturing and knot tying are completed. Two additional sacral sutures are then placed superiorly to allow for adequate visualization of the sacrum during the suturing, and the excess mesh is trimmed.

The mesh should then be retroperitonealized to reduce the risk of small-bowel obstruction. The closure of the peritoneum is facilitated by the extension of the initial peritoneal incision from the sacrum inferiorly in the midline through the cul-de-sac and along the posterior vaginal wall at the time of sacral dissection. An enterocele repair can be accomplished as closure over the mesh obliterates the cul de sac. The peritoneum is closed with a running, locking, braided, absorbable suture.

I typically perform cystoscopy at the end of the procedure to confirm bilateral ureteral patency using intravenous indigo carmine.

Fortunately, presacral bleeding is rare. However, if presacral hemorrhage does occur, it is important to remain calm and remember that pressure can be applied with most available robotic instruments. (For example, even scissors work well if the wrist of the instrument is used.) If the bleeding does not respond to pressure, a bipolar forceps can be used, depending on the location and source of the bleeding. If bleeding continues, then FloSeal—a thrombin matrix that will usually and very effectively stop the bleeding—can be considered.

If the clinical situation warrants additional procedures, such as a posterior repair or a suburethral sling for urinary incontinence, these can easily be performed after the robot is undocked. If necessary, we perform uterine morcellation after undocking the robot.

Our typical patient at Duke has an overnight stay in our 23-hour observation unit and requires minimal oral pain medication.

Dr. Visco is a consultant for Intuitive Surgical Inc.

Port placement: A “W-like” configuration for port placement works well. This configuration reduces any competition between the two left robotic arms. Intuitive Surgical

Presacral dissection: The presacral space is generally best viewed with a 30-degree down scope.

Anterior suturing: A Mega needle driver and SutureCut needle driver are used for anterior vaginal wall suturing.

Mesh to sacrum: The first and most inferior of the three sacral sutures is placed with a sliding knot. Photos courtesy Dr. Anthony Visco

Robotic Sacrocolpopexy

This is the third installment of the Master Class in Gynecologic Surgery dedicated to robotic surgery.

Whether the procedure is called robotic sacrocolpopexy or robotic-assisted laparoscopic sacrocolpopexy, Dr. Anthony Visco's excellent description will help the reader understand how the robot and the laparoscope can be used to modify the standard treatment for vaginal vault prolapse—the abdominal sacrocolpopexy—into a minimally invasive gynecologic procedure that can be incorporated into one's practice.

As Dr. Visco points out, the robotic procedure involves an obligatory learning curve and a need for practiced, efficient teamwork. However, as the surgeon and staff gain experience, robotic sacrocolpopexy can lead to outcomes similar to those of abdominal sacrocolpopexy, but with less blood loss and quicker recovery time.

Dr. Visco is director of the division of urogynecology and reconstructive pelvic surgery; director of gynecologic robotic surgery; and vice chair of the department of obstetrics and gynecology at Duke University Medical Center in Durham, N.C. Dr. Visco has authored or coauthored nearly 50 peer-reviewed articles on, or related to, urogynecology.

In 2007, Dr. Visco performed a live robotic sacrocolpopexy in Madrid for an international conference on pelvic floor disorders, and a second live robotic sacrocolpopexy for the AAGL's 2007 annual meeting.

Some surgeons perform the procedure laparoscopically in an effort to decrease morbidity and recovery time, with some success. Overall, however, a laparoscopic approach has not been widely adopted because of the complex suturing and dissection involved, and the subsequently significant learning curve.

Robotic sacrocolpopexy is a new addition to our armamentarium and is an exciting option for me and other surgeons because it combines the advantages of open sacrocolpopexy with the decreased morbidity of laparoscopy.

A robotic approach to the tried-and-true abdominal sacrocolpopexy takes full advantage of all that robotic surgery offers. Instrument articulation, three-dimensional vision, tremor reduction, and improved ergonomics for the surgeon all make managing the mesh and intracorporeal suturing—as well as dissecting in the rectovaginal and presacral spaces—so much easier than would be the case with a standard laparoscopic approach.

Overall, sacrocolpopexy performed with the da Vinci surgical system—the only Food and Drug Administration-approved robotic device for use in gynecologic surgery—offers better access to the pelvis, compared with both the open and laparoscopic approaches.

We can truly replicate what we do in an open approach, but with less postoperative pain, less blood loss and scarring, and faster recovery. Robotic sacrocolpopexy can also be combined with total or supracervical hysterectomy for uterine prolapse.

Outcomes data are emerging. At the American Urogynecologic Society annual meeting last month, we presented our initial short-term data comparing robotic with traditional abdominal sacrocolpopexy for the treatment of both uterine and vaginal vault prolapse.

Postoperatively, based on a 6-week POPQ (Pelvic Organ Prolapse Quantification) examination, there was a similar degree of pelvic organ support in the 73 patients who underwent robotic surgery and the 105 patients who underwent traditional surgery. The length of hospital stay was significantly shorter with the robotic approach (1.3 days vs. 2.7 days), and estimated blood loss was significantly lower (103 mL vs. 255 mL).

The operative time for the colpopexy and all other procedures, including hysterectomy and slings, was significantly longer in the robotic group (328 vs. 225 minutes). This time is expected to decrease, however, as all members of the surgical team, including fellows, residents, and surgical staff, progress through the learning curve.

Patient Selection and Positioning

I now offer the procedure to any patient to whom I would recommend a sacrocolpopexy. In the initial stages of adopting a robotic approach, however, it makes sense to be more selective and to perform relatively straightforward surgeries. This means starting with patients who are relatively thin (with body mass indices less than 30 kg/m

Initial patients should also have a reasonably sized uterus (if present) and few comorbidities. Pulmonary morbidity (emphysema or chronic obstructive pulmonary disease, for instance) is a relative contraindication, especially for initial cases, because these patients may not tolerate the Trendelenburg position, which is required for the surgery.

In addition, although robotic sacrocolpopexy can be used for uterine prolapse, I recommend starting with patients who have vaginal vault prolapse so that the surgeon can focus on a single robotic procedure. As their experience grows, surgeons can easily perform a combined robotic hysterectomy with sacrocolpopexy for the treatment of uterine prolapse. I primarily perform a supracervical hysterectomy in combination with a sacrocolpopexy in an attempt to reduce the risk of mesh erosion.

When the patient is positioned at the start of the surgery, her arms and shoulders and all “pressure points” should be well padded with foam, but I do not find a need for shoulder pads. I typically use an extra-large vacuum bean bag to keep the patient firmly in place while she is in the moderate to steep Trendelenburg position, but the use of a gel pad placed between the patient and the bed is an alternative approach to keep the patient from sliding cephalad during the surgery.

Port Placement, Setup, and Preparation

For robotic sacrocolpopexy, five trocar sites are used with a four-arm robotic system: three for operative robotic arms, one for the camera, and one to be used as the assistant's port for suction and irrigation, assistance with traction/countertraction, and the introduction of suture and mesh. (The bedside assistant is also helpful for instrument swaps, during uterine morcellation, and for any trocar depth repositioning that is necessary.)

Initially, we tried several different port locations. We have found that a “W-like” configuration for our port placement works well. We place the camera trocar at the umbilicus to accommodate the endoscope and the camera arm. This represents the middle of our “W.”

We then place two robotic ports at the two inferior apices of the “W.” The lateral ends of the “W” are each located about 2 cm inferior to the level of the umbilicus. The right lateral port is the assistant's port, which is used to introduce mesh, suture, and the like. The left lateral port is for the third robotic operative arm and is particularly helpful in moving the sigmoid laterally to expose the sacrum.

Using this configuration, we have reduced any competition between the two left robotic arms while we operate either in the pelvis or at the sacrum.

Some surgeons place the camera port higher (above the umbilicus), but I do not care for this placement because it can partially impede the view over the sacral promontory. (Placement of the camera port above the umbilicus is necessary for enlarged uteri, however.) After initial entry, a 0-degree scope should be used to place the other ports.

It is important to maintain at least 10 cm between robotic ports, and at least 6 cm between the robotic port and the assistant's port to reduce external collision of the robotic instrument arms.

Before docking the robotic arms of the patientside cart and placing the various EndoWrist instruments, I laparoscopically remove any small-bowel adhesions or other abdominal wall adhesions. This way, I have the tactile sensation that robotics does not provide. I then retract the sigmoid and move the small bowel out of the pelvis to expose the sacrum and the sacral promontory.

At this point and still prior to docking, it is also important to identify the ureters, the sacral promontory, the midline with the sigmoid retracted, the middle sacral vessels, and the iliac vessels. The left common iliac vessels, particularly the vein, can occasionally be identified crossing very close to the sacral promontory.

The operating table should be lowered and the patientside cart should be positioned as high as possible to clear the patient's legs, and then—after all overhead lights and equipment are moved to the side—the cart can be rolled into position between the patient's legs and aligned in a straight line with the camera arm and umbilical camera port. Docking can then be easily accomplished.

Open communication with the anesthesiology team is important. Robotic sacrocolpopexy is associated with significantly less blood loss (typically less than 25 mL) and less insensible loss than is open sacrocolpopexy. Therefore intravenous fluids should generally be limited to a liter or less.

Surgical Steps

If the patient has uterine prolapse, this can be addressed first with a supracervical or total hysterectomy. I prefer supracervical hysterectomies, assuming that the patient's Pap smears have been normal, in an attempt to reduce the risk of mesh erosion. After the hysterectomy, I place the uterus along the left lateral gutter for morcellation at the end of the procedure and after the system is undocked.

With either type of hysterectomy, the use of a colpotomy ring—either a KOH cup or a VCARE device—works nicely. We find this helpful in manipulating the uterus and defining the cervical-vaginal junction, even during supracervical hysterectomies, because it helps in the dissection of the bladder flap.

After the bladder flap is dissected off the anterior vaginal wall (close to the anterior vaginal wall to avoid cystotomy and to identify the avascular plane), the rectovaginal septum is developed. Approximately 6-8 cm of anterior vaginal wall are exposed.

The placement of round, 31- to 33-mm EEA (end-to-end anastomosis) sizers in the vagina to manipulate the vaginal apex helps with the bladder flap dissection, which can be challenging in patients who have had a previous cesarean section, hysterectomy, or vaginal reconstructive procedure—especially those performed with vaginally placed mesh. Occasionally, the bladder is found densely adherent over the apex of the vagina and adherent to the proximal posterior vaginal wall.

I frequently have an additional, smaller (29-mm) sizer placed in the rectum to help clearly identify the rectovaginal septum and facilitate the dissection.

During the rectovaginal dissection, the vaginal EEA sizer should be oriented anteriorly to better expose the posterior vaginal wall. Between 6 cm and 10 cm of the posterior vaginal wall should be dissected, while the camera is kept at midline and oriented to the horizon.

At this point, I frequently switch to a 30-degree down scope to develop the presacral space. This enables me to see over the sacral promontory and enhances my view. Depending on the configuration of the sacrum, it is possible to complete the surgery with a 0-degree scope. However, the view of the presacral space is generally significantly improved with the 30-degree down scope.

The sigmoid is retracted laterally by the third operative arm, and the peritoneum is lifted up, or tented, over the sacrum in the midline to avoid injury to a vessel. Our goal is to identify the anterior longitudinal ligament, and this area can be fairly vascular. Once the anterior longitudinal ligament is identified, the presacral peritoneal dissection can be extended inferiorly to the vagina.

I use a Y-shaped polypropylene mesh (AMS) and introduce it, trimmed to the appropriate width and length, in the proper anatomical orientation. I place the distal and lateral sutures on the anterior vaginal wall first, and then place several (four to eight) additional sutures to secure the mesh to the anterior vaginal wall. To suture, I use a Mega needle driver in the left hand and a SutureCut needle driver in the right. The SutureCut needle driver is similar to the Mega needle driver, but it also has a cutting mechanism that provides enhanced autonomy to the console surgeon and makes suturing more efficient overall.

Using the third operative robotic arm, I then roll the sacral end of the mesh and lift it anteriorly, which allows the posterior mesh to drape nicely over the posterior vaginal wall. The longer posterior mesh can then be easily sutured to the posterior wall of the vagina. For the posterior vaginal-wall mesh attachment, I usually start at the vaginal apex and work my way inferiorly. Throughout the surgery, I use permanent sutures of CV-2 Gore-Tex.

I then adjust the mesh tension, ensuring that it will be attached to the sacrum without undue tension and with equal distribution of support to the anterior and posterior of the vagina. Once this is determined, the excess mesh is trimmed.

I typically place three sacral sutures to secure the mesh to the sacrum. I place the inferiormost suture first, using a slip (or sliding) knot. This is a one-way knot that allows the mesh to be easily attached to the sacrum without the need for an assistant to hold the mesh against the sacrum while the suturing and knot tying are completed. Two additional sacral sutures are then placed superiorly to allow for adequate visualization of the sacrum during the suturing, and the excess mesh is trimmed.

The mesh should then be retroperitonealized to reduce the risk of small-bowel obstruction. The closure of the peritoneum is facilitated by the extension of the initial peritoneal incision from the sacrum inferiorly in the midline through the cul-de-sac and along the posterior vaginal wall at the time of sacral dissection. An enterocele repair can be accomplished as closure over the mesh obliterates the cul de sac. The peritoneum is closed with a running, locking, braided, absorbable suture.

I typically perform cystoscopy at the end of the procedure to confirm bilateral ureteral patency using intravenous indigo carmine.

Fortunately, presacral bleeding is rare. However, if presacral hemorrhage does occur, it is important to remain calm and remember that pressure can be applied with most available robotic instruments. (For example, even scissors work well if the wrist of the instrument is used.) If the bleeding does not respond to pressure, a bipolar forceps can be used, depending on the location and source of the bleeding. If bleeding continues, then FloSeal—a thrombin matrix that will usually and very effectively stop the bleeding—can be considered.

If the clinical situation warrants additional procedures, such as a posterior repair or a suburethral sling for urinary incontinence, these can easily be performed after the robot is undocked. If necessary, we perform uterine morcellation after undocking the robot.

Our typical patient at Duke has an overnight stay in our 23-hour observation unit and requires minimal oral pain medication.

Dr. Visco is a consultant for Intuitive Surgical Inc.

Port placement: A “W-like” configuration for port placement works well. This configuration reduces any competition between the two left robotic arms. Intuitive Surgical

Presacral dissection: The presacral space is generally best viewed with a 30-degree down scope.

Anterior suturing: A Mega needle driver and SutureCut needle driver are used for anterior vaginal wall suturing.

Mesh to sacrum: The first and most inferior of the three sacral sutures is placed with a sliding knot. Photos courtesy Dr. Anthony Visco

Robotic Sacrocolpopexy

This is the third installment of the Master Class in Gynecologic Surgery dedicated to robotic surgery.

Whether the procedure is called robotic sacrocolpopexy or robotic-assisted laparoscopic sacrocolpopexy, Dr. Anthony Visco's excellent description will help the reader understand how the robot and the laparoscope can be used to modify the standard treatment for vaginal vault prolapse—the abdominal sacrocolpopexy—into a minimally invasive gynecologic procedure that can be incorporated into one's practice.

As Dr. Visco points out, the robotic procedure involves an obligatory learning curve and a need for practiced, efficient teamwork. However, as the surgeon and staff gain experience, robotic sacrocolpopexy can lead to outcomes similar to those of abdominal sacrocolpopexy, but with less blood loss and quicker recovery time.

Dr. Visco is director of the division of urogynecology and reconstructive pelvic surgery; director of gynecologic robotic surgery; and vice chair of the department of obstetrics and gynecology at Duke University Medical Center in Durham, N.C. Dr. Visco has authored or coauthored nearly 50 peer-reviewed articles on, or related to, urogynecology.

In 2007, Dr. Visco performed a live robotic sacrocolpopexy in Madrid for an international conference on pelvic floor disorders, and a second live robotic sacrocolpopexy for the AAGL's 2007 annual meeting.

Some surgeons perform the procedure laparoscopically in an effort to decrease morbidity and recovery time, with some success. Overall, however, a laparoscopic approach has not been widely adopted because of the complex suturing and dissection involved, and the subsequently significant learning curve.

Robotic sacrocolpopexy is a new addition to our armamentarium and is an exciting option for me and other surgeons because it combines the advantages of open sacrocolpopexy with the decreased morbidity of laparoscopy.

A robotic approach to the tried-and-true abdominal sacrocolpopexy takes full advantage of all that robotic surgery offers. Instrument articulation, three-dimensional vision, tremor reduction, and improved ergonomics for the surgeon all make managing the mesh and intracorporeal suturing—as well as dissecting in the rectovaginal and presacral spaces—so much easier than would be the case with a standard laparoscopic approach.

Overall, sacrocolpopexy performed with the da Vinci surgical system—the only Food and Drug Administration-approved robotic device for use in gynecologic surgery—offers better access to the pelvis, compared with both the open and laparoscopic approaches.

We can truly replicate what we do in an open approach, but with less postoperative pain, less blood loss and scarring, and faster recovery. Robotic sacrocolpopexy can also be combined with total or supracervical hysterectomy for uterine prolapse.

Outcomes data are emerging. At the American Urogynecologic Society annual meeting last month, we presented our initial short-term data comparing robotic with traditional abdominal sacrocolpopexy for the treatment of both uterine and vaginal vault prolapse.

Postoperatively, based on a 6-week POPQ (Pelvic Organ Prolapse Quantification) examination, there was a similar degree of pelvic organ support in the 73 patients who underwent robotic surgery and the 105 patients who underwent traditional surgery. The length of hospital stay was significantly shorter with the robotic approach (1.3 days vs. 2.7 days), and estimated blood loss was significantly lower (103 mL vs. 255 mL).

The operative time for the colpopexy and all other procedures, including hysterectomy and slings, was significantly longer in the robotic group (328 vs. 225 minutes). This time is expected to decrease, however, as all members of the surgical team, including fellows, residents, and surgical staff, progress through the learning curve.

Patient Selection and Positioning

I now offer the procedure to any patient to whom I would recommend a sacrocolpopexy. In the initial stages of adopting a robotic approach, however, it makes sense to be more selective and to perform relatively straightforward surgeries. This means starting with patients who are relatively thin (with body mass indices less than 30 kg/m

Initial patients should also have a reasonably sized uterus (if present) and few comorbidities. Pulmonary morbidity (emphysema or chronic obstructive pulmonary disease, for instance) is a relative contraindication, especially for initial cases, because these patients may not tolerate the Trendelenburg position, which is required for the surgery.

In addition, although robotic sacrocolpopexy can be used for uterine prolapse, I recommend starting with patients who have vaginal vault prolapse so that the surgeon can focus on a single robotic procedure. As their experience grows, surgeons can easily perform a combined robotic hysterectomy with sacrocolpopexy for the treatment of uterine prolapse. I primarily perform a supracervical hysterectomy in combination with a sacrocolpopexy in an attempt to reduce the risk of mesh erosion.

When the patient is positioned at the start of the surgery, her arms and shoulders and all “pressure points” should be well padded with foam, but I do not find a need for shoulder pads. I typically use an extra-large vacuum bean bag to keep the patient firmly in place while she is in the moderate to steep Trendelenburg position, but the use of a gel pad placed between the patient and the bed is an alternative approach to keep the patient from sliding cephalad during the surgery.

Port Placement, Setup, and Preparation

For robotic sacrocolpopexy, five trocar sites are used with a four-arm robotic system: three for operative robotic arms, one for the camera, and one to be used as the assistant's port for suction and irrigation, assistance with traction/countertraction, and the introduction of suture and mesh. (The bedside assistant is also helpful for instrument swaps, during uterine morcellation, and for any trocar depth repositioning that is necessary.)

Initially, we tried several different port locations. We have found that a “W-like” configuration for our port placement works well. We place the camera trocar at the umbilicus to accommodate the endoscope and the camera arm. This represents the middle of our “W.”

We then place two robotic ports at the two inferior apices of the “W.” The lateral ends of the “W” are each located about 2 cm inferior to the level of the umbilicus. The right lateral port is the assistant's port, which is used to introduce mesh, suture, and the like. The left lateral port is for the third robotic operative arm and is particularly helpful in moving the sigmoid laterally to expose the sacrum.

Using this configuration, we have reduced any competition between the two left robotic arms while we operate either in the pelvis or at the sacrum.

Some surgeons place the camera port higher (above the umbilicus), but I do not care for this placement because it can partially impede the view over the sacral promontory. (Placement of the camera port above the umbilicus is necessary for enlarged uteri, however.) After initial entry, a 0-degree scope should be used to place the other ports.

It is important to maintain at least 10 cm between robotic ports, and at least 6 cm between the robotic port and the assistant's port to reduce external collision of the robotic instrument arms.

Before docking the robotic arms of the patientside cart and placing the various EndoWrist instruments, I laparoscopically remove any small-bowel adhesions or other abdominal wall adhesions. This way, I have the tactile sensation that robotics does not provide. I then retract the sigmoid and move the small bowel out of the pelvis to expose the sacrum and the sacral promontory.

At this point and still prior to docking, it is also important to identify the ureters, the sacral promontory, the midline with the sigmoid retracted, the middle sacral vessels, and the iliac vessels. The left common iliac vessels, particularly the vein, can occasionally be identified crossing very close to the sacral promontory.

The operating table should be lowered and the patientside cart should be positioned as high as possible to clear the patient's legs, and then—after all overhead lights and equipment are moved to the side—the cart can be rolled into position between the patient's legs and aligned in a straight line with the camera arm and umbilical camera port. Docking can then be easily accomplished.

Open communication with the anesthesiology team is important. Robotic sacrocolpopexy is associated with significantly less blood loss (typically less than 25 mL) and less insensible loss than is open sacrocolpopexy. Therefore intravenous fluids should generally be limited to a liter or less.

Surgical Steps

If the patient has uterine prolapse, this can be addressed first with a supracervical or total hysterectomy. I prefer supracervical hysterectomies, assuming that the patient's Pap smears have been normal, in an attempt to reduce the risk of mesh erosion. After the hysterectomy, I place the uterus along the left lateral gutter for morcellation at the end of the procedure and after the system is undocked.

With either type of hysterectomy, the use of a colpotomy ring—either a KOH cup or a VCARE device—works nicely. We find this helpful in manipulating the uterus and defining the cervical-vaginal junction, even during supracervical hysterectomies, because it helps in the dissection of the bladder flap.

After the bladder flap is dissected off the anterior vaginal wall (close to the anterior vaginal wall to avoid cystotomy and to identify the avascular plane), the rectovaginal septum is developed. Approximately 6-8 cm of anterior vaginal wall are exposed.

The placement of round, 31- to 33-mm EEA (end-to-end anastomosis) sizers in the vagina to manipulate the vaginal apex helps with the bladder flap dissection, which can be challenging in patients who have had a previous cesarean section, hysterectomy, or vaginal reconstructive procedure—especially those performed with vaginally placed mesh. Occasionally, the bladder is found densely adherent over the apex of the vagina and adherent to the proximal posterior vaginal wall.

I frequently have an additional, smaller (29-mm) sizer placed in the rectum to help clearly identify the rectovaginal septum and facilitate the dissection.

During the rectovaginal dissection, the vaginal EEA sizer should be oriented anteriorly to better expose the posterior vaginal wall. Between 6 cm and 10 cm of the posterior vaginal wall should be dissected, while the camera is kept at midline and oriented to the horizon.

At this point, I frequently switch to a 30-degree down scope to develop the presacral space. This enables me to see over the sacral promontory and enhances my view. Depending on the configuration of the sacrum, it is possible to complete the surgery with a 0-degree scope. However, the view of the presacral space is generally significantly improved with the 30-degree down scope.

The sigmoid is retracted laterally by the third operative arm, and the peritoneum is lifted up, or tented, over the sacrum in the midline to avoid injury to a vessel. Our goal is to identify the anterior longitudinal ligament, and this area can be fairly vascular. Once the anterior longitudinal ligament is identified, the presacral peritoneal dissection can be extended inferiorly to the vagina.

I use a Y-shaped polypropylene mesh (AMS) and introduce it, trimmed to the appropriate width and length, in the proper anatomical orientation. I place the distal and lateral sutures on the anterior vaginal wall first, and then place several (four to eight) additional sutures to secure the mesh to the anterior vaginal wall. To suture, I use a Mega needle driver in the left hand and a SutureCut needle driver in the right. The SutureCut needle driver is similar to the Mega needle driver, but it also has a cutting mechanism that provides enhanced autonomy to the console surgeon and makes suturing more efficient overall.

Using the third operative robotic arm, I then roll the sacral end of the mesh and lift it anteriorly, which allows the posterior mesh to drape nicely over the posterior vaginal wall. The longer posterior mesh can then be easily sutured to the posterior wall of the vagina. For the posterior vaginal-wall mesh attachment, I usually start at the vaginal apex and work my way inferiorly. Throughout the surgery, I use permanent sutures of CV-2 Gore-Tex.

I then adjust the mesh tension, ensuring that it will be attached to the sacrum without undue tension and with equal distribution of support to the anterior and posterior of the vagina. Once this is determined, the excess mesh is trimmed.

I typically place three sacral sutures to secure the mesh to the sacrum. I place the inferiormost suture first, using a slip (or sliding) knot. This is a one-way knot that allows the mesh to be easily attached to the sacrum without the need for an assistant to hold the mesh against the sacrum while the suturing and knot tying are completed. Two additional sacral sutures are then placed superiorly to allow for adequate visualization of the sacrum during the suturing, and the excess mesh is trimmed.

The mesh should then be retroperitonealized to reduce the risk of small-bowel obstruction. The closure of the peritoneum is facilitated by the extension of the initial peritoneal incision from the sacrum inferiorly in the midline through the cul-de-sac and along the posterior vaginal wall at the time of sacral dissection. An enterocele repair can be accomplished as closure over the mesh obliterates the cul de sac. The peritoneum is closed with a running, locking, braided, absorbable suture.

I typically perform cystoscopy at the end of the procedure to confirm bilateral ureteral patency using intravenous indigo carmine.

Fortunately, presacral bleeding is rare. However, if presacral hemorrhage does occur, it is important to remain calm and remember that pressure can be applied with most available robotic instruments. (For example, even scissors work well if the wrist of the instrument is used.) If the bleeding does not respond to pressure, a bipolar forceps can be used, depending on the location and source of the bleeding. If bleeding continues, then FloSeal—a thrombin matrix that will usually and very effectively stop the bleeding—can be considered.

If the clinical situation warrants additional procedures, such as a posterior repair or a suburethral sling for urinary incontinence, these can easily be performed after the robot is undocked. If necessary, we perform uterine morcellation after undocking the robot.

Our typical patient at Duke has an overnight stay in our 23-hour observation unit and requires minimal oral pain medication.

Dr. Visco is a consultant for Intuitive Surgical Inc.

Port placement: A “W-like” configuration for port placement works well. This configuration reduces any competition between the two left robotic arms. Intuitive Surgical

Presacral dissection: The presacral space is generally best viewed with a 30-degree down scope.

Anterior suturing: A Mega needle driver and SutureCut needle driver are used for anterior vaginal wall suturing.

Mesh to sacrum: The first and most inferior of the three sacral sutures is placed with a sliding knot. Photos courtesy Dr. Anthony Visco

Robotic Sacrocolpopexy

This is the third installment of the Master Class in Gynecologic Surgery dedicated to robotic surgery.

Whether the procedure is called robotic sacrocolpopexy or robotic-assisted laparoscopic sacrocolpopexy, Dr. Anthony Visco's excellent description will help the reader understand how the robot and the laparoscope can be used to modify the standard treatment for vaginal vault prolapse—the abdominal sacrocolpopexy—into a minimally invasive gynecologic procedure that can be incorporated into one's practice.

As Dr. Visco points out, the robotic procedure involves an obligatory learning curve and a need for practiced, efficient teamwork. However, as the surgeon and staff gain experience, robotic sacrocolpopexy can lead to outcomes similar to those of abdominal sacrocolpopexy, but with less blood loss and quicker recovery time.

Dr. Visco is director of the division of urogynecology and reconstructive pelvic surgery; director of gynecologic robotic surgery; and vice chair of the department of obstetrics and gynecology at Duke University Medical Center in Durham, N.C. Dr. Visco has authored or coauthored nearly 50 peer-reviewed articles on, or related to, urogynecology.

In 2007, Dr. Visco performed a live robotic sacrocolpopexy in Madrid for an international conference on pelvic floor disorders, and a second live robotic sacrocolpopexy for the AAGL's 2007 annual meeting.