Michael S. Baggish, MD

The author reports no financial relationships relevant to this article.

CASE Postoperative abdominal pain. Is it gastroenteritis?

R.B., 35 years old, undergoes laparoscopic adhesiolysis for abdominal pain. Previously, she underwent exploratory laparotomy for a ruptured tubal pregnancy and, in separate operations, right oophorectomy via laparotomy for a ruptured corpus luteum cyst and diagnostic laparoscopy.

During the current surgery, extensive adhesions are observed, including interloop intestinal adhesions. The adhesions are lysed using monopolar scissors and a needle electrode, and R.B. is discharged home the same day.

Later that day and the next day, R.B. complains of abdominal pain that does not respond to prescribed analgesics, as well as nausea and vomiting. A nurse practitioner takes her call and prescribes a stronger analgesic, an antiemetic, and an antibiotic.

The following day, the patient’s husband telephones the treating gynecologist to report that his wife is still experiencing severe pain and nausea. He is told to bring her to the office, where she is described as having mild lower abdominal tenderness and mild rebound. An abdominal radiograph shows air-fluid levels and distended bowel. The gynecologist determines that the patient is experiencing gastroenteritis.

On postop day 3, R.B. continues to suffer from severe abdominal pain, nausea, and vomiting, and is unable to get out of bed. Her husband takes her to the emergency room at another hospital, where she is found to have diffuse peritonitis, absent bowel sounds, and:

• temperature, 101.8°F
• heart rate, 130/min
• respiratory rate, 24/min
• blood pressure, 90/60 mm Hg
• white blood cell (WBC) count, 21.5 × 10³/μL
• x-ray showing free air.

A general surgeon performs an exploratory laparotomy and finds foul-smelling abdominal fluid, 200 to 300 mL of pus, and a 1-cm perforation of the sigmoid colon. He performs sigmoid colon resection and a left-colon colostomy. A second laparotomy is necessary to drain a subphrenic abscess.

Four months later, the colostomy is taken down and bowel continuity is established.

Subsequently, the patient experiences episodes of gaseous and fecal incontinence, which are thought to be secondary to nerve damage. A ventral hernia is also diagnosed.

Could this outcome have been avoided?

No physician would wish a major complication of surgery upon any patient. Yet, sometimes, preventive efforts fall short of the goal or the physician is slow to suspect injury when the patient experiences postoperative abdominal pain and other symptoms. Intestinal injury may not be common during laparoscopy, but it is certainly not rare. And the longer diagnosis is delayed, the greater the risk of sepsis, even death.

Recognizing the limitations of laparoscopic surgery is a first step toward reducing the complication rate.^1,2 The ability to determine when laparotomy would better serve the patient’s interests is also critical, and prompt diagnosis and repair of any complication that does occur will ensure and speed the patient’s recovery.

The most serious complications associated with diagnostic and operative laparoscopy are major vessel and intestinal injuries. Both types of injury significantly raise the risk of mortality, which ranges from 2% to 23%.^3,4 The overall risk of injury to the gastrointestinal tract averages 1.6 to 2.0 for every 1,000 cases. The risk of major vessel injury averages 0.5 for every 1,000 cases.^5-9

In an earlier article for OBG Management, I reviewed vascular injury during laparoscopy.¹⁰ In Part 1 of this article, I focus on ways to avoid intestinal injury.In Part 2 , I outline strategies to identify it in a timely manner when it does occur.

Familiarity with intestinal and pelvic anatomy can prevent surgical injury

A thorough familiarity with pelvic anatomy is important to avoid injury at trocar entry, but it is even more critical in regard to operative injury. The small intestine spreads diffusely throughout the abdomen beneath the anterior abdominal wall. It lies beneath the umbilicus and anterior midline, whereas the large bowel is located at the periphery. The sigmoid colon swings left to right before joining the rectum anterior to the presacral space. The sigmoid junction with the descending colon lies well to the left of the midline, and the cecum lies at the pelvic brim to the right of midline.

In some women, the intestines droop into the pelvis and cover the adnexa, making adhesions between these structures highly likely following dissection in the vicinity of the tubes and ovaries.

Depending on the degree of redundancy of the mesentery of the cecum or sigmoid colon, these structures may droop into the pelvis and cover the adnexa. Therefore, adhesions are likely to develop between the large or small intestine, or both, and the adnexa following dissection in the vicinity of or immediately over the tubes and ovaries. Knowing the normal anatomic relationships is vital for restorative surgery.

When severe adhesions involve the large intestine, it is critical to know the anatomy of the retroperitoneum and be skilled enough to gain safe entry and to dissect that space to safely separate the adnexa when they are densely adhered to the pelvic sidewall in the area of the obturator fossa.

As laparoscopy evolves, the injury rate rises

Over the past 40 years, laparoscopy has evolved from an uncommonly utilized diagnostic tool to a minimally invasive alternative to laparotomy for even the most difficult and complex operations, reaching a high point with robotic laparoscopy. As this technology has developed, serious complications—to some degree, unique to laparoscopy—have increased. In the future, as less skilled surgeons perform a greater percentage of laparoscopic surgeries, a still greater number of complications will arise.

The frequency of intestinal perforation is not great relative to the total number of laparoscopic procedures performed. The TABLE lists several series totaling more than 380,000 laparoscopic operations. The risk of reported bowel perforation ranged from 0.6 to 6 for every 1,000 procedures, with a mean risk of 2.4 for every 1,000. However, these data are inconclusive because the total number of laparoscopic operations performed in the United States is not accurately known. Nor is the precise number of complications associated with these procedures known—specifically, the number of intestinal perforations—as no law requires them to be reported.

Research surveys are unreliable in many cases. In addition, the relative expertise of the surgeon is impossible to quantify. For example, although a surgeon may have many years of operative experience, it is unclear whether this always translates into skill or comfort with laparoscopic procedures. And, when a resident scrubs in with a faculty surgeon, any data collected fail to reflect which part of the surgery was performed by the resident and which by the fully trained gynecologist.

These unknown variables are important in terms of risk, surgical complications, and outcomes. Surgical skill is the greatest unknown factor in any outcome study of any surgical procedure.

TABLE

Studies of complications reveal: Gastrointestinal injury is no rare event during laparoscopic surgery

Classifying intestinal injuries

As in the case of major vessel injury, intestinal injury sustained during laparoscopy can be classified as either:

• Injury secondary to the approach. This category refers to entry complications associated with creation of the pneumoperitoneum and insertion of primary and secondary trocars.
• Injury secondary to the procedure or operation. This type of injury occurs as a result of manipulation with various devices during laparoscopy. The devices may include probes, forceps, scissors, or energy devices such as laser, electrosurgical, and ultrasonic instruments.

How trocar injury happens

Several studies have demonstrated that abdominal adhesions place any patient into a high-risk category for trocar injury to the intestines. Patients who have undergone multiple laparotomies, like the patient in the case that opened this article, are more likely to have severe adhesions and fall into the highest risk category for bowel perforation.¹¹ It is impossible to predict with any degree of accuracy whether the intestine is adherent to the entry site.

Pneumoperitoneum can be protective

Creation of a pneumoperitoneum creates a cushion of gas between the intestines and the anterior abdominal wall (provided the intestines are not adherent to the abdominal wall). Manufacturers of disposable trocars with a retractable shield recommend creating an adequate pneumoperitoneum so that the “safety shield” deploys quickly and properly, unlike direct insertion, in which no gas is infused and space is insufficient for complete shield activation.

Open laparoscopy techniques, which allow the surgeon to enter the peritoneal cavity by direct vision without a sharp trocar, may diminish but not eliminate the risk of bowel injury.

What the data show

Of the 130 intestinal injuries recently reported by Baggish, 62 of 81 (77%) small bowel injuries were related to trocar insertion, as were 20 of 49 (41%) large intestinal injuries.¹² In other words, 82 of 130 intestinal injuries (63%) were the direct result of trocar entry.

Bhoyrul and associates reported 629 trocar injuries, of which 182 were visceral.¹³ Of the 32 deaths, six were secondary to unrecognized bowel injury. Of 176 nonfatal visceral injuries, 128 (73%) involved the intestines, and 22 were unrecognized.

Optical-access and open laparoscopic systems were designed to prevent such injuries. Sharp and colleagues reported 24 intestinal injuries out of a total of 79 complications (30%) associated with optical-access trocars after reviewing data obtained from the Medical Device Reports (MDR) and Maude databases maintained by the Food and Drug Administration.¹⁴ In the Baggish series, 4.6% of injuries were associated with open laparoscopy.¹²

Champault and colleagues reviewed complications in a survey of 103,852 operations.¹⁵ Although they recommended use of open laparoscopy as opposed to blind insertion, they presented no data on the safety of open techniques.

How intraoperative injury happens

Operative injury of the large or small bowel often occurs during sharp or blunt dissection, performed during laparoscopy using accessory mechanical or energy devices. The latter type of device is utilized increasingly because laparoscopic knot tying and suturing are rather awkward and slow, and laparoscopic suturing to control bleeding is difficult. The size of the needle required for laparoscopic suture placement must be small enough to navigate a trocar sleeve.

Avoid blunt dissection when adhesions are present

The separation of dense adhesions between the intestines and neighboring bowel, other viscera, or abdominal wall is risky when blunt dissection is used. The tensile strength of the fibrotic connective tissue may well exceed that of the thin intestinal wall. Tearing the adhesion free may bring with it a portion of the bowel wall. Such injuries are frequently missed or described as serosal injuries and left unexplored and unrepaired.

Hydrodissection is a safer alternative. It involves the infiltration of sterile water or saline under low pressure between the parietal peritoneum and underlying retroperitoneal structures, providing a safe and natural plane for dissection. In addition, when the CO₂ laser is used, the liquid acts as a heat sink to absorb any penetrating laser energy.

Energy devices create thermal effects

Energy devices used to cut tissue during operative laparoscopy coagulate blood vessels in a variety of ways, but the common pathway is thermal. Many hypotheses have evolved to explain how vessels are sealed, but none has demonstrated nonthermal activity except for cryocoagulation.

The devices most commonly used for cutting and hemostasis at laparoscopy are:

• electrosurgical (both monopolar and bipolar). Bipolar electrosurgical devices have advantages over monopolar devices when it comes to high-frequency leaks, direct coupling, and capacitive coupling.
• laser (CO₂, holmium:YAG, Nd:YAG, KTP-532, argon). As I mentioned, CO₂ laser devices are effectively backstopped by water, especially in strategic areas such as over and around intestines, major vessels, and the ureters.
• ultrasonic (Harmonic Scalpel, ultrasonic aspirator [CUSA]).

Laser and ultrasonic devices do not require a flow of electrons to create coagulation, but do produce heat that will spread peripherally by thermal conduction from the zone of impact (target).

The extent of energy-inflicted injury cannot be predicted

Inadvertent injury with energy devices can occur directly through contact with the bowel, indirectly by heat conduction through tissue, through capacitive coupling (monopolar electrical only), and by forward scatter (laser only).

Upon direct contact with the intestine, energy devices cut into the tissue in a manner similar to mechanical scissors or a knife but produce a larger wound. The reason? The transfer of heat to areas adjacent to the primary wound produces additional necrosis. Heat conduction, capacitive coupling, high-frequency leaks, and front scatter coagulate the intestinal wall with subsequent tissue devitalization and necrosis, the extent of which depends on the power density at contact and the duration of energy applied.

It is impossible to predict the depth or area of devitalization in energy-inflicted injury by visualization of the event.

In the Baggish review of 130 intestinal injuries, the number of injuries sustained during the operative procedure was 19 involving the small intestine and 29 involving the large bowel.¹² Of this subset, 44% (21 cases) were secondary to the use of energy devices, with monopolar electrosurgical instruments alone accounting for 9 (43%) of the injuries.

Even best-laid plans can go awry

Despite our best intentions and precautions, accidents do sometimes happen, and bowel injury is no exception.In Part 2 of this article, I detail steps you can take to detect injuries in as timely a manner as possible.

The author reports no financial relationships relevant to this article.

CASE Postoperative abdominal pain. Is it gastroenteritis?

R.B., 35 years old, undergoes laparoscopic adhesiolysis for abdominal pain. Previously, she underwent exploratory laparotomy for a ruptured tubal pregnancy and, in separate operations, right oophorectomy via laparotomy for a ruptured corpus luteum cyst and diagnostic laparoscopy.

During the current surgery, extensive adhesions are observed, including interloop intestinal adhesions. The adhesions are lysed using monopolar scissors and a needle electrode, and R.B. is discharged home the same day.

Later that day and the next day, R.B. complains of abdominal pain that does not respond to prescribed analgesics, as well as nausea and vomiting. A nurse practitioner takes her call and prescribes a stronger analgesic, an antiemetic, and an antibiotic.

The following day, the patient’s husband telephones the treating gynecologist to report that his wife is still experiencing severe pain and nausea. He is told to bring her to the office, where she is described as having mild lower abdominal tenderness and mild rebound. An abdominal radiograph shows air-fluid levels and distended bowel. The gynecologist determines that the patient is experiencing gastroenteritis.

On postop day 3, R.B. continues to suffer from severe abdominal pain, nausea, and vomiting, and is unable to get out of bed. Her husband takes her to the emergency room at another hospital, where she is found to have diffuse peritonitis, absent bowel sounds, and:

• temperature, 101.8°F
• heart rate, 130/min
• respiratory rate, 24/min
• blood pressure, 90/60 mm Hg
• white blood cell (WBC) count, 21.5 × 10³/μL
• x-ray showing free air.

A general surgeon performs an exploratory laparotomy and finds foul-smelling abdominal fluid, 200 to 300 mL of pus, and a 1-cm perforation of the sigmoid colon. He performs sigmoid colon resection and a left-colon colostomy. A second laparotomy is necessary to drain a subphrenic abscess.

Four months later, the colostomy is taken down and bowel continuity is established.

Subsequently, the patient experiences episodes of gaseous and fecal incontinence, which are thought to be secondary to nerve damage. A ventral hernia is also diagnosed.

Could this outcome have been avoided?

No physician would wish a major complication of surgery upon any patient. Yet, sometimes, preventive efforts fall short of the goal or the physician is slow to suspect injury when the patient experiences postoperative abdominal pain and other symptoms. Intestinal injury may not be common during laparoscopy, but it is certainly not rare. And the longer diagnosis is delayed, the greater the risk of sepsis, even death.

Recognizing the limitations of laparoscopic surgery is a first step toward reducing the complication rate.^1,2 The ability to determine when laparotomy would better serve the patient’s interests is also critical, and prompt diagnosis and repair of any complication that does occur will ensure and speed the patient’s recovery.

The most serious complications associated with diagnostic and operative laparoscopy are major vessel and intestinal injuries. Both types of injury significantly raise the risk of mortality, which ranges from 2% to 23%.^3,4 The overall risk of injury to the gastrointestinal tract averages 1.6 to 2.0 for every 1,000 cases. The risk of major vessel injury averages 0.5 for every 1,000 cases.^5-9

In an earlier article for OBG Management, I reviewed vascular injury during laparoscopy.¹⁰ In Part 1 of this article, I focus on ways to avoid intestinal injury.In Part 2 , I outline strategies to identify it in a timely manner when it does occur.

Familiarity with intestinal and pelvic anatomy can prevent surgical injury

A thorough familiarity with pelvic anatomy is important to avoid injury at trocar entry, but it is even more critical in regard to operative injury. The small intestine spreads diffusely throughout the abdomen beneath the anterior abdominal wall. It lies beneath the umbilicus and anterior midline, whereas the large bowel is located at the periphery. The sigmoid colon swings left to right before joining the rectum anterior to the presacral space. The sigmoid junction with the descending colon lies well to the left of the midline, and the cecum lies at the pelvic brim to the right of midline.

In some women, the intestines droop into the pelvis and cover the adnexa, making adhesions between these structures highly likely following dissection in the vicinity of the tubes and ovaries.

Depending on the degree of redundancy of the mesentery of the cecum or sigmoid colon, these structures may droop into the pelvis and cover the adnexa. Therefore, adhesions are likely to develop between the large or small intestine, or both, and the adnexa following dissection in the vicinity of or immediately over the tubes and ovaries. Knowing the normal anatomic relationships is vital for restorative surgery.

When severe adhesions involve the large intestine, it is critical to know the anatomy of the retroperitoneum and be skilled enough to gain safe entry and to dissect that space to safely separate the adnexa when they are densely adhered to the pelvic sidewall in the area of the obturator fossa.

As laparoscopy evolves, the injury rate rises

Over the past 40 years, laparoscopy has evolved from an uncommonly utilized diagnostic tool to a minimally invasive alternative to laparotomy for even the most difficult and complex operations, reaching a high point with robotic laparoscopy. As this technology has developed, serious complications—to some degree, unique to laparoscopy—have increased. In the future, as less skilled surgeons perform a greater percentage of laparoscopic surgeries, a still greater number of complications will arise.

The frequency of intestinal perforation is not great relative to the total number of laparoscopic procedures performed. The TABLE lists several series totaling more than 380,000 laparoscopic operations. The risk of reported bowel perforation ranged from 0.6 to 6 for every 1,000 procedures, with a mean risk of 2.4 for every 1,000. However, these data are inconclusive because the total number of laparoscopic operations performed in the United States is not accurately known. Nor is the precise number of complications associated with these procedures known—specifically, the number of intestinal perforations—as no law requires them to be reported.

Research surveys are unreliable in many cases. In addition, the relative expertise of the surgeon is impossible to quantify. For example, although a surgeon may have many years of operative experience, it is unclear whether this always translates into skill or comfort with laparoscopic procedures. And, when a resident scrubs in with a faculty surgeon, any data collected fail to reflect which part of the surgery was performed by the resident and which by the fully trained gynecologist.

These unknown variables are important in terms of risk, surgical complications, and outcomes. Surgical skill is the greatest unknown factor in any outcome study of any surgical procedure.

TABLE

Studies of complications reveal: Gastrointestinal injury is no rare event during laparoscopic surgery

Classifying intestinal injuries

As in the case of major vessel injury, intestinal injury sustained during laparoscopy can be classified as either:

• Injury secondary to the approach. This category refers to entry complications associated with creation of the pneumoperitoneum and insertion of primary and secondary trocars.
• Injury secondary to the procedure or operation. This type of injury occurs as a result of manipulation with various devices during laparoscopy. The devices may include probes, forceps, scissors, or energy devices such as laser, electrosurgical, and ultrasonic instruments.

How trocar injury happens

Several studies have demonstrated that abdominal adhesions place any patient into a high-risk category for trocar injury to the intestines. Patients who have undergone multiple laparotomies, like the patient in the case that opened this article, are more likely to have severe adhesions and fall into the highest risk category for bowel perforation.¹¹ It is impossible to predict with any degree of accuracy whether the intestine is adherent to the entry site.

Pneumoperitoneum can be protective

Creation of a pneumoperitoneum creates a cushion of gas between the intestines and the anterior abdominal wall (provided the intestines are not adherent to the abdominal wall). Manufacturers of disposable trocars with a retractable shield recommend creating an adequate pneumoperitoneum so that the “safety shield” deploys quickly and properly, unlike direct insertion, in which no gas is infused and space is insufficient for complete shield activation.

Open laparoscopy techniques, which allow the surgeon to enter the peritoneal cavity by direct vision without a sharp trocar, may diminish but not eliminate the risk of bowel injury.

What the data show

Of the 130 intestinal injuries recently reported by Baggish, 62 of 81 (77%) small bowel injuries were related to trocar insertion, as were 20 of 49 (41%) large intestinal injuries.¹² In other words, 82 of 130 intestinal injuries (63%) were the direct result of trocar entry.

Bhoyrul and associates reported 629 trocar injuries, of which 182 were visceral.¹³ Of the 32 deaths, six were secondary to unrecognized bowel injury. Of 176 nonfatal visceral injuries, 128 (73%) involved the intestines, and 22 were unrecognized.

Optical-access and open laparoscopic systems were designed to prevent such injuries. Sharp and colleagues reported 24 intestinal injuries out of a total of 79 complications (30%) associated with optical-access trocars after reviewing data obtained from the Medical Device Reports (MDR) and Maude databases maintained by the Food and Drug Administration.¹⁴ In the Baggish series, 4.6% of injuries were associated with open laparoscopy.¹²

Champault and colleagues reviewed complications in a survey of 103,852 operations.¹⁵ Although they recommended use of open laparoscopy as opposed to blind insertion, they presented no data on the safety of open techniques.

How intraoperative injury happens

Operative injury of the large or small bowel often occurs during sharp or blunt dissection, performed during laparoscopy using accessory mechanical or energy devices. The latter type of device is utilized increasingly because laparoscopic knot tying and suturing are rather awkward and slow, and laparoscopic suturing to control bleeding is difficult. The size of the needle required for laparoscopic suture placement must be small enough to navigate a trocar sleeve.

Avoid blunt dissection when adhesions are present

The separation of dense adhesions between the intestines and neighboring bowel, other viscera, or abdominal wall is risky when blunt dissection is used. The tensile strength of the fibrotic connective tissue may well exceed that of the thin intestinal wall. Tearing the adhesion free may bring with it a portion of the bowel wall. Such injuries are frequently missed or described as serosal injuries and left unexplored and unrepaired.

Hydrodissection is a safer alternative. It involves the infiltration of sterile water or saline under low pressure between the parietal peritoneum and underlying retroperitoneal structures, providing a safe and natural plane for dissection. In addition, when the CO₂ laser is used, the liquid acts as a heat sink to absorb any penetrating laser energy.

Energy devices create thermal effects

Energy devices used to cut tissue during operative laparoscopy coagulate blood vessels in a variety of ways, but the common pathway is thermal. Many hypotheses have evolved to explain how vessels are sealed, but none has demonstrated nonthermal activity except for cryocoagulation.

The devices most commonly used for cutting and hemostasis at laparoscopy are:

• electrosurgical (both monopolar and bipolar). Bipolar electrosurgical devices have advantages over monopolar devices when it comes to high-frequency leaks, direct coupling, and capacitive coupling.
• laser (CO₂, holmium:YAG, Nd:YAG, KTP-532, argon). As I mentioned, CO₂ laser devices are effectively backstopped by water, especially in strategic areas such as over and around intestines, major vessels, and the ureters.
• ultrasonic (Harmonic Scalpel, ultrasonic aspirator [CUSA]).

Laser and ultrasonic devices do not require a flow of electrons to create coagulation, but do produce heat that will spread peripherally by thermal conduction from the zone of impact (target).

The extent of energy-inflicted injury cannot be predicted

Inadvertent injury with energy devices can occur directly through contact with the bowel, indirectly by heat conduction through tissue, through capacitive coupling (monopolar electrical only), and by forward scatter (laser only).

Upon direct contact with the intestine, energy devices cut into the tissue in a manner similar to mechanical scissors or a knife but produce a larger wound. The reason? The transfer of heat to areas adjacent to the primary wound produces additional necrosis. Heat conduction, capacitive coupling, high-frequency leaks, and front scatter coagulate the intestinal wall with subsequent tissue devitalization and necrosis, the extent of which depends on the power density at contact and the duration of energy applied.

It is impossible to predict the depth or area of devitalization in energy-inflicted injury by visualization of the event.

In the Baggish review of 130 intestinal injuries, the number of injuries sustained during the operative procedure was 19 involving the small intestine and 29 involving the large bowel.¹² Of this subset, 44% (21 cases) were secondary to the use of energy devices, with monopolar electrosurgical instruments alone accounting for 9 (43%) of the injuries.

Even best-laid plans can go awry

Despite our best intentions and precautions, accidents do sometimes happen, and bowel injury is no exception.In Part 2 of this article, I detail steps you can take to detect injuries in as timely a manner as possible.

The author reports no financial relationships relevant to this article.

CASE Postoperative abdominal pain. Is it gastroenteritis?

R.B., 35 years old, undergoes laparoscopic adhesiolysis for abdominal pain. Previously, she underwent exploratory laparotomy for a ruptured tubal pregnancy and, in separate operations, right oophorectomy via laparotomy for a ruptured corpus luteum cyst and diagnostic laparoscopy.

During the current surgery, extensive adhesions are observed, including interloop intestinal adhesions. The adhesions are lysed using monopolar scissors and a needle electrode, and R.B. is discharged home the same day.

Later that day and the next day, R.B. complains of abdominal pain that does not respond to prescribed analgesics, as well as nausea and vomiting. A nurse practitioner takes her call and prescribes a stronger analgesic, an antiemetic, and an antibiotic.

The following day, the patient’s husband telephones the treating gynecologist to report that his wife is still experiencing severe pain and nausea. He is told to bring her to the office, where she is described as having mild lower abdominal tenderness and mild rebound. An abdominal radiograph shows air-fluid levels and distended bowel. The gynecologist determines that the patient is experiencing gastroenteritis.

On postop day 3, R.B. continues to suffer from severe abdominal pain, nausea, and vomiting, and is unable to get out of bed. Her husband takes her to the emergency room at another hospital, where she is found to have diffuse peritonitis, absent bowel sounds, and:

• temperature, 101.8°F
• heart rate, 130/min
• respiratory rate, 24/min
• blood pressure, 90/60 mm Hg
• white blood cell (WBC) count, 21.5 × 10³/μL
• x-ray showing free air.

A general surgeon performs an exploratory laparotomy and finds foul-smelling abdominal fluid, 200 to 300 mL of pus, and a 1-cm perforation of the sigmoid colon. He performs sigmoid colon resection and a left-colon colostomy. A second laparotomy is necessary to drain a subphrenic abscess.

Four months later, the colostomy is taken down and bowel continuity is established.

Subsequently, the patient experiences episodes of gaseous and fecal incontinence, which are thought to be secondary to nerve damage. A ventral hernia is also diagnosed.

Could this outcome have been avoided?

No physician would wish a major complication of surgery upon any patient. Yet, sometimes, preventive efforts fall short of the goal or the physician is slow to suspect injury when the patient experiences postoperative abdominal pain and other symptoms. Intestinal injury may not be common during laparoscopy, but it is certainly not rare. And the longer diagnosis is delayed, the greater the risk of sepsis, even death.

Recognizing the limitations of laparoscopic surgery is a first step toward reducing the complication rate.^1,2 The ability to determine when laparotomy would better serve the patient’s interests is also critical, and prompt diagnosis and repair of any complication that does occur will ensure and speed the patient’s recovery.

The most serious complications associated with diagnostic and operative laparoscopy are major vessel and intestinal injuries. Both types of injury significantly raise the risk of mortality, which ranges from 2% to 23%.^3,4 The overall risk of injury to the gastrointestinal tract averages 1.6 to 2.0 for every 1,000 cases. The risk of major vessel injury averages 0.5 for every 1,000 cases.^5-9

In an earlier article for OBG Management, I reviewed vascular injury during laparoscopy.¹⁰ In Part 1 of this article, I focus on ways to avoid intestinal injury.In Part 2 , I outline strategies to identify it in a timely manner when it does occur.

Familiarity with intestinal and pelvic anatomy can prevent surgical injury

A thorough familiarity with pelvic anatomy is important to avoid injury at trocar entry, but it is even more critical in regard to operative injury. The small intestine spreads diffusely throughout the abdomen beneath the anterior abdominal wall. It lies beneath the umbilicus and anterior midline, whereas the large bowel is located at the periphery. The sigmoid colon swings left to right before joining the rectum anterior to the presacral space. The sigmoid junction with the descending colon lies well to the left of the midline, and the cecum lies at the pelvic brim to the right of midline.

In some women, the intestines droop into the pelvis and cover the adnexa, making adhesions between these structures highly likely following dissection in the vicinity of the tubes and ovaries.

Depending on the degree of redundancy of the mesentery of the cecum or sigmoid colon, these structures may droop into the pelvis and cover the adnexa. Therefore, adhesions are likely to develop between the large or small intestine, or both, and the adnexa following dissection in the vicinity of or immediately over the tubes and ovaries. Knowing the normal anatomic relationships is vital for restorative surgery.

When severe adhesions involve the large intestine, it is critical to know the anatomy of the retroperitoneum and be skilled enough to gain safe entry and to dissect that space to safely separate the adnexa when they are densely adhered to the pelvic sidewall in the area of the obturator fossa.

As laparoscopy evolves, the injury rate rises

Over the past 40 years, laparoscopy has evolved from an uncommonly utilized diagnostic tool to a minimally invasive alternative to laparotomy for even the most difficult and complex operations, reaching a high point with robotic laparoscopy. As this technology has developed, serious complications—to some degree, unique to laparoscopy—have increased. In the future, as less skilled surgeons perform a greater percentage of laparoscopic surgeries, a still greater number of complications will arise.

The frequency of intestinal perforation is not great relative to the total number of laparoscopic procedures performed. The TABLE lists several series totaling more than 380,000 laparoscopic operations. The risk of reported bowel perforation ranged from 0.6 to 6 for every 1,000 procedures, with a mean risk of 2.4 for every 1,000. However, these data are inconclusive because the total number of laparoscopic operations performed in the United States is not accurately known. Nor is the precise number of complications associated with these procedures known—specifically, the number of intestinal perforations—as no law requires them to be reported.

Research surveys are unreliable in many cases. In addition, the relative expertise of the surgeon is impossible to quantify. For example, although a surgeon may have many years of operative experience, it is unclear whether this always translates into skill or comfort with laparoscopic procedures. And, when a resident scrubs in with a faculty surgeon, any data collected fail to reflect which part of the surgery was performed by the resident and which by the fully trained gynecologist.

These unknown variables are important in terms of risk, surgical complications, and outcomes. Surgical skill is the greatest unknown factor in any outcome study of any surgical procedure.

TABLE

Studies of complications reveal: Gastrointestinal injury is no rare event during laparoscopic surgery

Classifying intestinal injuries

As in the case of major vessel injury, intestinal injury sustained during laparoscopy can be classified as either:

• Injury secondary to the approach. This category refers to entry complications associated with creation of the pneumoperitoneum and insertion of primary and secondary trocars.
• Injury secondary to the procedure or operation. This type of injury occurs as a result of manipulation with various devices during laparoscopy. The devices may include probes, forceps, scissors, or energy devices such as laser, electrosurgical, and ultrasonic instruments.

How trocar injury happens

Several studies have demonstrated that abdominal adhesions place any patient into a high-risk category for trocar injury to the intestines. Patients who have undergone multiple laparotomies, like the patient in the case that opened this article, are more likely to have severe adhesions and fall into the highest risk category for bowel perforation.¹¹ It is impossible to predict with any degree of accuracy whether the intestine is adherent to the entry site.

Pneumoperitoneum can be protective

Creation of a pneumoperitoneum creates a cushion of gas between the intestines and the anterior abdominal wall (provided the intestines are not adherent to the abdominal wall). Manufacturers of disposable trocars with a retractable shield recommend creating an adequate pneumoperitoneum so that the “safety shield” deploys quickly and properly, unlike direct insertion, in which no gas is infused and space is insufficient for complete shield activation.

Open laparoscopy techniques, which allow the surgeon to enter the peritoneal cavity by direct vision without a sharp trocar, may diminish but not eliminate the risk of bowel injury.

What the data show

Of the 130 intestinal injuries recently reported by Baggish, 62 of 81 (77%) small bowel injuries were related to trocar insertion, as were 20 of 49 (41%) large intestinal injuries.¹² In other words, 82 of 130 intestinal injuries (63%) were the direct result of trocar entry.

Bhoyrul and associates reported 629 trocar injuries, of which 182 were visceral.¹³ Of the 32 deaths, six were secondary to unrecognized bowel injury. Of 176 nonfatal visceral injuries, 128 (73%) involved the intestines, and 22 were unrecognized.

Optical-access and open laparoscopic systems were designed to prevent such injuries. Sharp and colleagues reported 24 intestinal injuries out of a total of 79 complications (30%) associated with optical-access trocars after reviewing data obtained from the Medical Device Reports (MDR) and Maude databases maintained by the Food and Drug Administration.¹⁴ In the Baggish series, 4.6% of injuries were associated with open laparoscopy.¹²

Champault and colleagues reviewed complications in a survey of 103,852 operations.¹⁵ Although they recommended use of open laparoscopy as opposed to blind insertion, they presented no data on the safety of open techniques.

How intraoperative injury happens

Operative injury of the large or small bowel often occurs during sharp or blunt dissection, performed during laparoscopy using accessory mechanical or energy devices. The latter type of device is utilized increasingly because laparoscopic knot tying and suturing are rather awkward and slow, and laparoscopic suturing to control bleeding is difficult. The size of the needle required for laparoscopic suture placement must be small enough to navigate a trocar sleeve.

Avoid blunt dissection when adhesions are present

The separation of dense adhesions between the intestines and neighboring bowel, other viscera, or abdominal wall is risky when blunt dissection is used. The tensile strength of the fibrotic connective tissue may well exceed that of the thin intestinal wall. Tearing the adhesion free may bring with it a portion of the bowel wall. Such injuries are frequently missed or described as serosal injuries and left unexplored and unrepaired.

Hydrodissection is a safer alternative. It involves the infiltration of sterile water or saline under low pressure between the parietal peritoneum and underlying retroperitoneal structures, providing a safe and natural plane for dissection. In addition, when the CO₂ laser is used, the liquid acts as a heat sink to absorb any penetrating laser energy.

Energy devices create thermal effects

Energy devices used to cut tissue during operative laparoscopy coagulate blood vessels in a variety of ways, but the common pathway is thermal. Many hypotheses have evolved to explain how vessels are sealed, but none has demonstrated nonthermal activity except for cryocoagulation.

The devices most commonly used for cutting and hemostasis at laparoscopy are:

• electrosurgical (both monopolar and bipolar). Bipolar electrosurgical devices have advantages over monopolar devices when it comes to high-frequency leaks, direct coupling, and capacitive coupling.
• laser (CO₂, holmium:YAG, Nd:YAG, KTP-532, argon). As I mentioned, CO₂ laser devices are effectively backstopped by water, especially in strategic areas such as over and around intestines, major vessels, and the ureters.
• ultrasonic (Harmonic Scalpel, ultrasonic aspirator [CUSA]).

Laser and ultrasonic devices do not require a flow of electrons to create coagulation, but do produce heat that will spread peripherally by thermal conduction from the zone of impact (target).

The extent of energy-inflicted injury cannot be predicted

Inadvertent injury with energy devices can occur directly through contact with the bowel, indirectly by heat conduction through tissue, through capacitive coupling (monopolar electrical only), and by forward scatter (laser only).

Upon direct contact with the intestine, energy devices cut into the tissue in a manner similar to mechanical scissors or a knife but produce a larger wound. The reason? The transfer of heat to areas adjacent to the primary wound produces additional necrosis. Heat conduction, capacitive coupling, high-frequency leaks, and front scatter coagulate the intestinal wall with subsequent tissue devitalization and necrosis, the extent of which depends on the power density at contact and the duration of energy applied.

It is impossible to predict the depth or area of devitalization in energy-inflicted injury by visualization of the event.

In the Baggish review of 130 intestinal injuries, the number of injuries sustained during the operative procedure was 19 involving the small intestine and 29 involving the large bowel.¹² Of this subset, 44% (21 cases) were secondary to the use of energy devices, with monopolar electrosurgical instruments alone accounting for 9 (43%) of the injuries.

Even best-laid plans can go awry

Despite our best intentions and precautions, accidents do sometimes happen, and bowel injury is no exception.In Part 2 of this article, I detail steps you can take to detect injuries in as timely a manner as possible.

In Part 1 of this article, I outlined circumstances in which abdominal adhesions should be anticipated and described strategies to prevent intestinal injury during operative procedures. Here, I describe ways to identify intestinal injury as soon as possible after it occurs, which is vital to prevent serious sequelae such as sepsis and even death.

During operative laparoscopy, a quick search for injury through the laparoscope cannot assure any surgeon that the intestinal wall has not been seriously denuded. A damaged muscularis—even if it is not recognized as transmural injury—may subsequently rupture if it is not appropriately repaired intraoperatively.

Following dissection of adhesions, irrigate the neighboring intestine with sterile saline, and perform a detailed inspection of the intestine to ascertain integrity of the bowel wall. The color of the intestine is important, as it can indicate whether the abundant vascular supply has been compromised. Include a detailed description of the intestines in the operative note.

Avoid stapling or vascular clips when repairing any wound; careful suturing is preferred.

Why early diagnosis is critical

The most favorable time to diagnose an iatrogenic intestinal perforation is within the intraoperative period. Prompt recognition and repair of bowel perforation offers several advantages:

• A second or third operation is less likely (
• The risk of abdominal sepsis is decreased.
  
• The volume of peripheral injury to the intestine is reduced.
  
• The patient can be followed for subsequent complications more precisely, permitting earlier diagnosis, more timely and effective treatment, and lower morbidity.
  

The 130 intestinal injuries reported by Baggish reflect the clinical significance of timely diagnosis.¹ Seventy percent of small bowel and 51% of large bowel perforations were correctly diagnosed more than 48 hours postoperatively. Sepsis was present in a majority of these cases at the time of diagnosis.

Reasons for diagnostic delay

• The gynecologic surgeon fails to place intestinal injury at the top of the differential diagnosis.
  
• A surgical consultant is delayed in making a correct diagnosis. Surgeons have less experience with perforation than do gynecologists, and invariably consider the postoperative abdominal problem to be ileus or intestinal obstruction. The presence of postoperative pneumoperitoneum is incorrectly thought to be lingering CO₂ gas from the initial laparoscopy rather than air from a perforated viscus.
  
• Ancillary diagnosis confuses the primary physician. Pleural effusion, chest pain, and tachypnea are usually thought to indicate pulmonary embolism; as a result, the gynecologist and consulting pulmonologist focus on pulmonary embolus and deep-vein thrombosis. Only a spiral computed tomography (CT) scan, a ventilation perfusion (VQ) scan, or arteriogram quickly rules pulmonary embolus in or out. Peritonitis associated with ileus or third-space fluid leakage resulting in diaphragmatic elevation also creates pleural effusion, tachypnea, and dyspnea.
  

Presumptive diagnosis is critical

Definitive diagnosis of intestinal perforation happens at the operating table under direct vision and is corroborated by the pathology laboratory if bowel resection is performed. However, presumptive diagnosis helps overcome inertia and gets the patient to the operating room sooner.

The process by which the presumptive diagnosis is made is the most important issue in this article. The shorter the process, the lower the patient’s morbidity, and vice versa.

Look for steady improvement. Worry when it is absent

After any laparoscopic operation, the postoperative course should be one of steady clinical improvement. When a patient deviates from this model, the foremost presumptive diagnosis should be laparoscopy-associated injury, and the intestine should top the list of organs that may be injured. Other diagnoses should be subordinate to the principal presumptive diagnosis; these include ileus, bowel obstruction, pulmonary embolus, gastroenteritis, and hematoma, to name a few.

I do not mean to imply that a potentially life-threatening complication such as pulmonary embolus should not be ruled in or out, but that the necessary imaging should be performed in a timely fashion. The abdominal-pelvic CT scan will offer clues to the presence of free air, free fluid, air-fluid levels, and foreign bodies. It also is useful in detecting intra-abdominal—specifically, subphrenic—abscess. If necessary, a VQ scan or spiral CT scan can then be performed without delaying the diagnosis of the primary intra-abdominal catastrophe responsible for the pulmonary symptoms.

In the opening case, before making an improbable presumptive diagnosis, the surgeon should have questioned why an otherwise healthy woman would coincidentally develop gastroenteritis after laparoscopic surgery. The same can be said for diagnoses of intestinal obstruction or vascular thrombosis involving the intestinal blood supply.

Typical presentation of the injured patient

An injured patient does not experience daily improvement and a return to normal activity. Instead, the postoperative period is marked by persistent and worsening pain, often compounded by nausea or vomiting, or both. The patient may complain of fever, chills, weakness, or simply not feeling normal. Breathing may be labored. As time elapses, the symptoms become worse.

Reports of more than one visit to an emergency care facility are not uncommon. When examined, the patient exhibits direct or rebound tenderness, or both. The abdomen may or may not be distended, but usually is increased in girth. Bowel sounds are diminished or absent.

Vital signs initially reveal normal, low-grade, or subnormal temperature, and tachycardia, tachypnea, and normal blood pressure are typical. As time and sepsis progress, however, fever and hypotension develop. Most other symptoms and signs become progressively more abnormal in direct proportion to the length of time the diagnosis is delayed.

Seminal laboratory values for sepsis include a lower than normal white blood cell (WBC) count, elevated immature white-cell elements (e.g., “bandemia”), elevated liver chemistries, and an elevated serum creatinine level.

Mortality is most often the result of overwhelming and prolonged sepsis, leading to multiorgan failure, bleeding diathesis, and adult respiratory distress syndrome.

Among 130 laparoscopic surgical cases complicated by bowel injury and reported by Baggish, sepsis was diagnosed in 100% of colonic perforations and 50% of small-bowel perforations when the diagnosis was delayed more than 48 hours after surgery.¹

TABLE 1 lists the signs and frequency of sepsis in these 100 cases, and TABLE 2 collates the signs and symptoms that were observed. Peritoneal cultures obtained at the time of exploratory laparotomy revealed multiple organisms (polymicrobial) in 60% of cases.

TABLE 1

Frequency of signs of sepsis among 130 patients with colon or small-bowel injury

Watch for signs and symptoms of intestinal injury

Concurrent injuries to neighboring structures

A number of collateral injuries may occur in conjunction with intestinal perforation, depending on the location of the trauma. The most dangerous combination includes indirect laceration of one of the major retroperitoneal vessels. A through-and-through perforation of the cecum can also involve one or more of the right iliac vessels. A trocar perforation of the ileum may continue directly into the presacral space or pass above it and penetrate the left common iliac vein or aorta. Similarly, perforation of the sigmoid colon may penetrate the left iliac vessels.

Careful inspection of the posterior peritoneum for tears and evidence of retroperitoneal hematoma is required to avoid missing a serious collateral injury. More likely, however, is a penetrating injury to the small bowel presenting with collateral mesenteric damage and compromise of the blood supply of an entire segment of bowel. The ureter and bladder may also be injured when dissection along the pelvic sidewall, or a trocar thrust, deviates to the right or left of midline. In thin patients, the stomach may be perforated as well as the small intestine or transverse colon.

In one memorable case, a primary trocar penetrated the omentum, injuring several underlying structures. In its transit, the trocar passed through both the anterior and posterior walls of the duodenum and finally entered the superior mesenteric artery. The gynecologic surgeon performing the laparoscopic tubal ligation failed to recognize any of these injuries. The patient went into shock in the recovery room and was returned to the operating room. Fortunately, a transplant surgeon from a neighboring theater was immediately available to consult and repair the damage.

Another danger: intestinal ischemic necrosis

Abnormalities in splanchnic blood flow are sometimes caused by elevations in intra-abdominal pressure. Caldwell and Ricotta inflated the abdomens of nine dogs and reported a significant reduction of blood flow to omentum, stomach, duodenum, jejunum, ileum, colon, pancreas, liver, and spleen, but not to the adrenal glands.² The splanchnic flow reductions essentially shunted blood away from abdominal viscera with auto-transfusion to the heart, lungs, and systemic circulation.

Eleftheriadis and colleagues studied 16 women randomized to laparoscopic versus open cholecystectomy.³ Significant depression of the hepatic microcirculation during the period of CO₂ gas insufflation was noted in the laparoscopy cohort but not in the control group. Gastric mucosal ischemia also was observed in the laparoscopy group.

Several case reports of catastrophic intestinal ischemia have appeared in the literature (1994–1995).^4-7 These articles have mainly involved laparoscopic upper abdominal operations in elderly people.

Recently, however, Hasson and colleagues reported a case of possible ischemic necrosis of the small intestine following laparoscopic adhesiolysis and bipolar myolysis.⁸ The authors emphasized that CO₂ pneumoperitoneum reduces splanchnic blood flow, predisposing the patient to ischemia, but that ischemia with infarction requires an underlying vasculopathy or inciting factors such as traction on a short mesentery, atherosclerosis, or thrombosis.

A high index of suspicion for bowel ischemia following laparoscopic surgery should occur when, postoperatively, a patient experiences inordinately severe abdominal pain associated with tachypnea, tachycardia, and alterations in the WBC count. A paucity of physical abdominal signs in the early phases of this disorder should alert the clinician to the possibility of bowel ischemia.

Diagnosing and treating ischemia

A CT scan with contrast can suggest ischemia, but angiography is usually required for definitive diagnosis.

Treatment begins with infusion of papaverine into the intestinal vasculature via angiography cannula. In some cases, anticoagulation may be indicated. Surgery by laparotomy is clearly indicated for patients who fail to respond to vasodilatation measures.

This condition can be ameliorated by intermittent intraoperative decompression of the abdomen. Avoiding prolonged CO₂ pneumoperitoneum and a lengthy laparoscopic operation also may diminish the risk of intestinal ischemia.

In Part 1 of this article, I outlined circumstances in which abdominal adhesions should be anticipated and described strategies to prevent intestinal injury during operative procedures. Here, I describe ways to identify intestinal injury as soon as possible after it occurs, which is vital to prevent serious sequelae such as sepsis and even death.

During operative laparoscopy, a quick search for injury through the laparoscope cannot assure any surgeon that the intestinal wall has not been seriously denuded. A damaged muscularis—even if it is not recognized as transmural injury—may subsequently rupture if it is not appropriately repaired intraoperatively.

Following dissection of adhesions, irrigate the neighboring intestine with sterile saline, and perform a detailed inspection of the intestine to ascertain integrity of the bowel wall. The color of the intestine is important, as it can indicate whether the abundant vascular supply has been compromised. Include a detailed description of the intestines in the operative note.

Avoid stapling or vascular clips when repairing any wound; careful suturing is preferred.

Why early diagnosis is critical

The most favorable time to diagnose an iatrogenic intestinal perforation is within the intraoperative period. Prompt recognition and repair of bowel perforation offers several advantages:

• A second or third operation is less likely (
• The risk of abdominal sepsis is decreased.
  
• The volume of peripheral injury to the intestine is reduced.
  
• The patient can be followed for subsequent complications more precisely, permitting earlier diagnosis, more timely and effective treatment, and lower morbidity.
  

The 130 intestinal injuries reported by Baggish reflect the clinical significance of timely diagnosis.¹ Seventy percent of small bowel and 51% of large bowel perforations were correctly diagnosed more than 48 hours postoperatively. Sepsis was present in a majority of these cases at the time of diagnosis.

Reasons for diagnostic delay

• The gynecologic surgeon fails to place intestinal injury at the top of the differential diagnosis.
  
• A surgical consultant is delayed in making a correct diagnosis. Surgeons have less experience with perforation than do gynecologists, and invariably consider the postoperative abdominal problem to be ileus or intestinal obstruction. The presence of postoperative pneumoperitoneum is incorrectly thought to be lingering CO₂ gas from the initial laparoscopy rather than air from a perforated viscus.
  
• Ancillary diagnosis confuses the primary physician. Pleural effusion, chest pain, and tachypnea are usually thought to indicate pulmonary embolism; as a result, the gynecologist and consulting pulmonologist focus on pulmonary embolus and deep-vein thrombosis. Only a spiral computed tomography (CT) scan, a ventilation perfusion (VQ) scan, or arteriogram quickly rules pulmonary embolus in or out. Peritonitis associated with ileus or third-space fluid leakage resulting in diaphragmatic elevation also creates pleural effusion, tachypnea, and dyspnea.
  

Presumptive diagnosis is critical

Definitive diagnosis of intestinal perforation happens at the operating table under direct vision and is corroborated by the pathology laboratory if bowel resection is performed. However, presumptive diagnosis helps overcome inertia and gets the patient to the operating room sooner.

The process by which the presumptive diagnosis is made is the most important issue in this article. The shorter the process, the lower the patient’s morbidity, and vice versa.

Look for steady improvement. Worry when it is absent

After any laparoscopic operation, the postoperative course should be one of steady clinical improvement. When a patient deviates from this model, the foremost presumptive diagnosis should be laparoscopy-associated injury, and the intestine should top the list of organs that may be injured. Other diagnoses should be subordinate to the principal presumptive diagnosis; these include ileus, bowel obstruction, pulmonary embolus, gastroenteritis, and hematoma, to name a few.

I do not mean to imply that a potentially life-threatening complication such as pulmonary embolus should not be ruled in or out, but that the necessary imaging should be performed in a timely fashion. The abdominal-pelvic CT scan will offer clues to the presence of free air, free fluid, air-fluid levels, and foreign bodies. It also is useful in detecting intra-abdominal—specifically, subphrenic—abscess. If necessary, a VQ scan or spiral CT scan can then be performed without delaying the diagnosis of the primary intra-abdominal catastrophe responsible for the pulmonary symptoms.

In the opening case, before making an improbable presumptive diagnosis, the surgeon should have questioned why an otherwise healthy woman would coincidentally develop gastroenteritis after laparoscopic surgery. The same can be said for diagnoses of intestinal obstruction or vascular thrombosis involving the intestinal blood supply.

Typical presentation of the injured patient

An injured patient does not experience daily improvement and a return to normal activity. Instead, the postoperative period is marked by persistent and worsening pain, often compounded by nausea or vomiting, or both. The patient may complain of fever, chills, weakness, or simply not feeling normal. Breathing may be labored. As time elapses, the symptoms become worse.

Reports of more than one visit to an emergency care facility are not uncommon. When examined, the patient exhibits direct or rebound tenderness, or both. The abdomen may or may not be distended, but usually is increased in girth. Bowel sounds are diminished or absent.

Vital signs initially reveal normal, low-grade, or subnormal temperature, and tachycardia, tachypnea, and normal blood pressure are typical. As time and sepsis progress, however, fever and hypotension develop. Most other symptoms and signs become progressively more abnormal in direct proportion to the length of time the diagnosis is delayed.

Seminal laboratory values for sepsis include a lower than normal white blood cell (WBC) count, elevated immature white-cell elements (e.g., “bandemia”), elevated liver chemistries, and an elevated serum creatinine level.

Mortality is most often the result of overwhelming and prolonged sepsis, leading to multiorgan failure, bleeding diathesis, and adult respiratory distress syndrome.

Among 130 laparoscopic surgical cases complicated by bowel injury and reported by Baggish, sepsis was diagnosed in 100% of colonic perforations and 50% of small-bowel perforations when the diagnosis was delayed more than 48 hours after surgery.¹

TABLE 1 lists the signs and frequency of sepsis in these 100 cases, and TABLE 2 collates the signs and symptoms that were observed. Peritoneal cultures obtained at the time of exploratory laparotomy revealed multiple organisms (polymicrobial) in 60% of cases.

TABLE 1

Frequency of signs of sepsis among 130 patients with colon or small-bowel injury

Watch for signs and symptoms of intestinal injury

Concurrent injuries to neighboring structures

A number of collateral injuries may occur in conjunction with intestinal perforation, depending on the location of the trauma. The most dangerous combination includes indirect laceration of one of the major retroperitoneal vessels. A through-and-through perforation of the cecum can also involve one or more of the right iliac vessels. A trocar perforation of the ileum may continue directly into the presacral space or pass above it and penetrate the left common iliac vein or aorta. Similarly, perforation of the sigmoid colon may penetrate the left iliac vessels.

Careful inspection of the posterior peritoneum for tears and evidence of retroperitoneal hematoma is required to avoid missing a serious collateral injury. More likely, however, is a penetrating injury to the small bowel presenting with collateral mesenteric damage and compromise of the blood supply of an entire segment of bowel. The ureter and bladder may also be injured when dissection along the pelvic sidewall, or a trocar thrust, deviates to the right or left of midline. In thin patients, the stomach may be perforated as well as the small intestine or transverse colon.

In one memorable case, a primary trocar penetrated the omentum, injuring several underlying structures. In its transit, the trocar passed through both the anterior and posterior walls of the duodenum and finally entered the superior mesenteric artery. The gynecologic surgeon performing the laparoscopic tubal ligation failed to recognize any of these injuries. The patient went into shock in the recovery room and was returned to the operating room. Fortunately, a transplant surgeon from a neighboring theater was immediately available to consult and repair the damage.

Another danger: intestinal ischemic necrosis

Abnormalities in splanchnic blood flow are sometimes caused by elevations in intra-abdominal pressure. Caldwell and Ricotta inflated the abdomens of nine dogs and reported a significant reduction of blood flow to omentum, stomach, duodenum, jejunum, ileum, colon, pancreas, liver, and spleen, but not to the adrenal glands.² The splanchnic flow reductions essentially shunted blood away from abdominal viscera with auto-transfusion to the heart, lungs, and systemic circulation.

Eleftheriadis and colleagues studied 16 women randomized to laparoscopic versus open cholecystectomy.³ Significant depression of the hepatic microcirculation during the period of CO₂ gas insufflation was noted in the laparoscopy cohort but not in the control group. Gastric mucosal ischemia also was observed in the laparoscopy group.

Several case reports of catastrophic intestinal ischemia have appeared in the literature (1994–1995).^4-7 These articles have mainly involved laparoscopic upper abdominal operations in elderly people.

Recently, however, Hasson and colleagues reported a case of possible ischemic necrosis of the small intestine following laparoscopic adhesiolysis and bipolar myolysis.⁸ The authors emphasized that CO₂ pneumoperitoneum reduces splanchnic blood flow, predisposing the patient to ischemia, but that ischemia with infarction requires an underlying vasculopathy or inciting factors such as traction on a short mesentery, atherosclerosis, or thrombosis.

A high index of suspicion for bowel ischemia following laparoscopic surgery should occur when, postoperatively, a patient experiences inordinately severe abdominal pain associated with tachypnea, tachycardia, and alterations in the WBC count. A paucity of physical abdominal signs in the early phases of this disorder should alert the clinician to the possibility of bowel ischemia.

Diagnosing and treating ischemia

A CT scan with contrast can suggest ischemia, but angiography is usually required for definitive diagnosis.

Treatment begins with infusion of papaverine into the intestinal vasculature via angiography cannula. In some cases, anticoagulation may be indicated. Surgery by laparotomy is clearly indicated for patients who fail to respond to vasodilatation measures.

This condition can be ameliorated by intermittent intraoperative decompression of the abdomen. Avoiding prolonged CO₂ pneumoperitoneum and a lengthy laparoscopic operation also may diminish the risk of intestinal ischemia.

In Part 1 of this article, I outlined circumstances in which abdominal adhesions should be anticipated and described strategies to prevent intestinal injury during operative procedures. Here, I describe ways to identify intestinal injury as soon as possible after it occurs, which is vital to prevent serious sequelae such as sepsis and even death.

During operative laparoscopy, a quick search for injury through the laparoscope cannot assure any surgeon that the intestinal wall has not been seriously denuded. A damaged muscularis—even if it is not recognized as transmural injury—may subsequently rupture if it is not appropriately repaired intraoperatively.

Following dissection of adhesions, irrigate the neighboring intestine with sterile saline, and perform a detailed inspection of the intestine to ascertain integrity of the bowel wall. The color of the intestine is important, as it can indicate whether the abundant vascular supply has been compromised. Include a detailed description of the intestines in the operative note.

Avoid stapling or vascular clips when repairing any wound; careful suturing is preferred.

Why early diagnosis is critical

The most favorable time to diagnose an iatrogenic intestinal perforation is within the intraoperative period. Prompt recognition and repair of bowel perforation offers several advantages:

• A second or third operation is less likely (
• The risk of abdominal sepsis is decreased.
  
• The volume of peripheral injury to the intestine is reduced.
  
• The patient can be followed for subsequent complications more precisely, permitting earlier diagnosis, more timely and effective treatment, and lower morbidity.
  

The 130 intestinal injuries reported by Baggish reflect the clinical significance of timely diagnosis.¹ Seventy percent of small bowel and 51% of large bowel perforations were correctly diagnosed more than 48 hours postoperatively. Sepsis was present in a majority of these cases at the time of diagnosis.

Reasons for diagnostic delay

• The gynecologic surgeon fails to place intestinal injury at the top of the differential diagnosis.
  
• A surgical consultant is delayed in making a correct diagnosis. Surgeons have less experience with perforation than do gynecologists, and invariably consider the postoperative abdominal problem to be ileus or intestinal obstruction. The presence of postoperative pneumoperitoneum is incorrectly thought to be lingering CO₂ gas from the initial laparoscopy rather than air from a perforated viscus.
  
• Ancillary diagnosis confuses the primary physician. Pleural effusion, chest pain, and tachypnea are usually thought to indicate pulmonary embolism; as a result, the gynecologist and consulting pulmonologist focus on pulmonary embolus and deep-vein thrombosis. Only a spiral computed tomography (CT) scan, a ventilation perfusion (VQ) scan, or arteriogram quickly rules pulmonary embolus in or out. Peritonitis associated with ileus or third-space fluid leakage resulting in diaphragmatic elevation also creates pleural effusion, tachypnea, and dyspnea.
  

Presumptive diagnosis is critical

Definitive diagnosis of intestinal perforation happens at the operating table under direct vision and is corroborated by the pathology laboratory if bowel resection is performed. However, presumptive diagnosis helps overcome inertia and gets the patient to the operating room sooner.

The process by which the presumptive diagnosis is made is the most important issue in this article. The shorter the process, the lower the patient’s morbidity, and vice versa.

Look for steady improvement. Worry when it is absent

After any laparoscopic operation, the postoperative course should be one of steady clinical improvement. When a patient deviates from this model, the foremost presumptive diagnosis should be laparoscopy-associated injury, and the intestine should top the list of organs that may be injured. Other diagnoses should be subordinate to the principal presumptive diagnosis; these include ileus, bowel obstruction, pulmonary embolus, gastroenteritis, and hematoma, to name a few.

I do not mean to imply that a potentially life-threatening complication such as pulmonary embolus should not be ruled in or out, but that the necessary imaging should be performed in a timely fashion. The abdominal-pelvic CT scan will offer clues to the presence of free air, free fluid, air-fluid levels, and foreign bodies. It also is useful in detecting intra-abdominal—specifically, subphrenic—abscess. If necessary, a VQ scan or spiral CT scan can then be performed without delaying the diagnosis of the primary intra-abdominal catastrophe responsible for the pulmonary symptoms.

In the opening case, before making an improbable presumptive diagnosis, the surgeon should have questioned why an otherwise healthy woman would coincidentally develop gastroenteritis after laparoscopic surgery. The same can be said for diagnoses of intestinal obstruction or vascular thrombosis involving the intestinal blood supply.

Typical presentation of the injured patient

An injured patient does not experience daily improvement and a return to normal activity. Instead, the postoperative period is marked by persistent and worsening pain, often compounded by nausea or vomiting, or both. The patient may complain of fever, chills, weakness, or simply not feeling normal. Breathing may be labored. As time elapses, the symptoms become worse.

Reports of more than one visit to an emergency care facility are not uncommon. When examined, the patient exhibits direct or rebound tenderness, or both. The abdomen may or may not be distended, but usually is increased in girth. Bowel sounds are diminished or absent.

Vital signs initially reveal normal, low-grade, or subnormal temperature, and tachycardia, tachypnea, and normal blood pressure are typical. As time and sepsis progress, however, fever and hypotension develop. Most other symptoms and signs become progressively more abnormal in direct proportion to the length of time the diagnosis is delayed.

Seminal laboratory values for sepsis include a lower than normal white blood cell (WBC) count, elevated immature white-cell elements (e.g., “bandemia”), elevated liver chemistries, and an elevated serum creatinine level.

Mortality is most often the result of overwhelming and prolonged sepsis, leading to multiorgan failure, bleeding diathesis, and adult respiratory distress syndrome.

Among 130 laparoscopic surgical cases complicated by bowel injury and reported by Baggish, sepsis was diagnosed in 100% of colonic perforations and 50% of small-bowel perforations when the diagnosis was delayed more than 48 hours after surgery.¹

TABLE 1 lists the signs and frequency of sepsis in these 100 cases, and TABLE 2 collates the signs and symptoms that were observed. Peritoneal cultures obtained at the time of exploratory laparotomy revealed multiple organisms (polymicrobial) in 60% of cases.

TABLE 1

Frequency of signs of sepsis among 130 patients with colon or small-bowel injury

Watch for signs and symptoms of intestinal injury

Concurrent injuries to neighboring structures

A number of collateral injuries may occur in conjunction with intestinal perforation, depending on the location of the trauma. The most dangerous combination includes indirect laceration of one of the major retroperitoneal vessels. A through-and-through perforation of the cecum can also involve one or more of the right iliac vessels. A trocar perforation of the ileum may continue directly into the presacral space or pass above it and penetrate the left common iliac vein or aorta. Similarly, perforation of the sigmoid colon may penetrate the left iliac vessels.

Careful inspection of the posterior peritoneum for tears and evidence of retroperitoneal hematoma is required to avoid missing a serious collateral injury. More likely, however, is a penetrating injury to the small bowel presenting with collateral mesenteric damage and compromise of the blood supply of an entire segment of bowel. The ureter and bladder may also be injured when dissection along the pelvic sidewall, or a trocar thrust, deviates to the right or left of midline. In thin patients, the stomach may be perforated as well as the small intestine or transverse colon.

In one memorable case, a primary trocar penetrated the omentum, injuring several underlying structures. In its transit, the trocar passed through both the anterior and posterior walls of the duodenum and finally entered the superior mesenteric artery. The gynecologic surgeon performing the laparoscopic tubal ligation failed to recognize any of these injuries. The patient went into shock in the recovery room and was returned to the operating room. Fortunately, a transplant surgeon from a neighboring theater was immediately available to consult and repair the damage.

Another danger: intestinal ischemic necrosis

Abnormalities in splanchnic blood flow are sometimes caused by elevations in intra-abdominal pressure. Caldwell and Ricotta inflated the abdomens of nine dogs and reported a significant reduction of blood flow to omentum, stomach, duodenum, jejunum, ileum, colon, pancreas, liver, and spleen, but not to the adrenal glands.² The splanchnic flow reductions essentially shunted blood away from abdominal viscera with auto-transfusion to the heart, lungs, and systemic circulation.

Eleftheriadis and colleagues studied 16 women randomized to laparoscopic versus open cholecystectomy.³ Significant depression of the hepatic microcirculation during the period of CO₂ gas insufflation was noted in the laparoscopy cohort but not in the control group. Gastric mucosal ischemia also was observed in the laparoscopy group.

Several case reports of catastrophic intestinal ischemia have appeared in the literature (1994–1995).^4-7 These articles have mainly involved laparoscopic upper abdominal operations in elderly people.

Recently, however, Hasson and colleagues reported a case of possible ischemic necrosis of the small intestine following laparoscopic adhesiolysis and bipolar myolysis.⁸ The authors emphasized that CO₂ pneumoperitoneum reduces splanchnic blood flow, predisposing the patient to ischemia, but that ischemia with infarction requires an underlying vasculopathy or inciting factors such as traction on a short mesentery, atherosclerosis, or thrombosis.

A high index of suspicion for bowel ischemia following laparoscopic surgery should occur when, postoperatively, a patient experiences inordinately severe abdominal pain associated with tachypnea, tachycardia, and alterations in the WBC count. A paucity of physical abdominal signs in the early phases of this disorder should alert the clinician to the possibility of bowel ischemia.

Diagnosing and treating ischemia

A CT scan with contrast can suggest ischemia, but angiography is usually required for definitive diagnosis.

Treatment begins with infusion of papaverine into the intestinal vasculature via angiography cannula. In some cases, anticoagulation may be indicated. Surgery by laparotomy is clearly indicated for patients who fail to respond to vasodilatation measures.

This condition can be ameliorated by intermittent intraoperative decompression of the abdomen. Avoiding prolonged CO₂ pneumoperitoneum and a lengthy laparoscopic operation also may diminish the risk of intestinal ischemia.