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Clinical significance
Continuous positive airway pressure remains the gold standard and first-line treatment for moderate to severe OSA. When CPAP and other medical therapies fail or are poorly adopted, surgical solutions - either standalone or in unison - can be directed to target precision therapy.
The newest of these techniques is neuromodulation of the lingual musculature, particularly by way of selective stimulation of the hypoglossal nerve, which first demonstrated success in human clinical trials in 1996.1 Upper airway stimulation (UAS) was formally FDA-approved in 2014 (Inspire Medical Systems, Inc). UAS is designed to eliminate clinically significant OSA through stimulation of the anteriorly directed branches of the hypoglossal nerve, increasing the posterior airway space in a multilevel fashion.2 Since this time, over 7,500 patients have been treated with Inspire in nine countries (United States, Germany, The Netherlands, Switzerland, Belgium, Spain, France, Italy, and Finland). Prospective, international multicenter trials have demonstrated 68% to 96% clinical efficacy in well selected individuals. This is defined as a ≥ 50% reduction in the apnea hypopnea index (AHI) to an overall AHI of ≤ 20/hour.3,4 Additionally, post-UAS analysis demonstrates subjective reduction in daytime sleepiness as reported by Epworth sleepiness scores, with improvements in sleep-related quality of life. Further, UAS reduces socially disruptive snoring with 85% of bedpartners reporting soft to no snoring at 48-month follow-up.5 The procedure has also demonstrated long-term cost benefit in the US health-care system.6
Background and pathophysiology
Oliven and colleagues7 first observed the critical finding that selective intra-muscular stimulation of the genioglossus muscle lowered airway critical closing pressure (PCrit), thereby stabilizing the pharyngeal airway. Conversely, activation of the “retrusor” musculature, namely the hyoglossus and styloglossus muscles, increased Pcrit, increasing collapsibility of the pharyngeal airway.
Therapeutic implantation requires three incisions directed to the neck, chest, and right rib space (between the 4th to 6th intercostal spaces), with an operative time of 90 minutes or less in experienced hands. The majority of patients are discharged on the day of the procedure. Morbidity remains low with minimal pain reported during recovery. The most common complication is that of temporary tongue weakness, which typically resolves within 2 to 3 weeks. While very infrequent, patients should be counseled on the risk of postoperative hematoma, which can precipitate infection and subsequent explant of the device. Average recovery time spans between 3 and 7 days with activation of the device 4 weeks after surgical implantation to allow for appropriate tissue healing and reduce the risk of dislodgement of the implanted components. In contrast to other surgical treatment options, UAS is also reversible with no underlying alteration to existing pharyngeal anatomy apart from external incisions created during the procedure.
Stimulation to titration
As the need for a multidisciplinary approach to salvage of patients failing first-line therapy for OSA continues to grow, UAS with its multilevel impact continues to be of key interest. In similar fashion to established medical therapies such as PAP and oral appliance therapy (OAT), close observation between sleep medicine specialists and the implanting surgeon during the adaptation period with attention paid to titration parameters such as stimulation duration, pulse width, amplitude, and polarity, allow optimization of response outcome.
The stimulation electrode, which is designed in the form of a cuff to envelope the anterior (protrusor) branches of the hypoglossal nerve receives electrical stimulation from the implanted pulse generator, implanted above the pectoralis muscle of the chest wall. This design allows for collaborative awake and overnight titration of the device as directed by a sleep medicine physician. Attention is paid not only to the voltage “strength” administered with each pulse but also the degree of synchronization between respiration and stimulation, as well as pattern of pulse administration. Our experience remains that true success and adaptation to therapy requires not just meticulous surgical technique but a diligent approach to postoperative therapeutic titration to achieve a comfortable, yet effective, voltage for maintaining airway patency. Thus, akin to initiation of CPAP, UAS requires regular follow-up and device fine-tuning with patient comfort taken into consideration to achieve optimal results, and patient expectation should be aligned with this process.
Current indications
Success in UAS relies heavily on appropriate presurgical evaluation and clinical phenotyping. The following surgical indications have been demonstrated in the Stimulation Therapy for Apnea Reduction (STAR) trial and subsequent 3-year clinical follow-up: AHI between 15 and 80 events/hour (with ≤ 25% central apneas) and a BMI ≤ 32.8
As OSA often results from multi-level airway collapse, UAS targets an increase not only in the diameter of the retropalatal/oropharyngeal airway space but also the antero-posterior hypopharyngeal airway. Original criteria for implantation excluded patients with a pattern of complete circumferential collapse (CCC) noted on dynamic airway evaluation during pre-implant drug-induced sleep endoscopy (DISE). DISE aims to precisely target dynamic airway collapse patterns during simulated (propofol or midazolom induced) sleep.
Future directions
The effects of UAS are dependent on upper-airway cross-sectional area, particularly diameter. In patients who demonstrate CCC, the anteroposterior direction of activation derived from the UAS stimulus is unable to overcome CCC. In a recent prospective study, our group demonstrated that CCC can be converted to an airway collapse pattern compatible with UAS implantation, using a modified palatopharyngoplasty prior to UAS implantation. By stabilizing the lateral walls of the oropharyngeal airway with pre-implant palatal surgery, UAS is able to successfully direct widening of the airway cross-sectional area in an antero-posterior fashion. This exciting finding potentially allows for expansion of current indications, thus opening treatment to a wider patient population.9 Still, UAS remains highly studied in a relatively uniform patient population with data in more diverse subsets requiring further directed attention to expand and better define optimal patient populations for treatment.
From the perspective of improving patient adaptation and tolerance in UAS, a well-established concept in the CPAP literature can be applied, as explained by the Starling resistor model. The starling resistor is comprised of two rigid tubes connected by a collapsible segment in between. In parallel, the pharynx is a collapsible muscular tube connected on either end by the nose/nasal cavity and the trachea – both of which are bony/cartilaginous, noncollapsible structures. As has been shown in the use of CPAP, the same pressure required to maintain stability of the collapsible muscular pharynx via nasal breathing may lead to pharyngeal collapse when applied orally.10 This concept has also been directed towards UAS with our clinical experience demonstrating that oro or oronasal breathers tend to require a higher amplitude to maintain airway patency versus nasal breathers. This is an important area for future-directed study as medically/surgically improving nasal breathing in UAS subjects may subsequently lower amplitude requirements and improve patient tolerance.
Future direction to allow for improvement in the technology for application in a broader populational segment, external or alternative device powering mechanisms, along with MRI Compatibility and reducing the number of required external incisions will continue to broaden the patient selection criteria. As we move from a “stimulation” to a precision-tailored “stimulation and titration” approach, the mid to long term data supporting UAS remains very promising with 5-year follow up demonstrating sustained polysomnographic and subjective reported outcomes in well selected patients.
Dr. Awad is Assistant Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Northwestern University, Chicago, Illinois. Dr. Capasso is Associate Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Stanford Hospital and Clinics, Stanford, California.
References
1. Schwartz AR et al. Electrical stimulation of the lingual musculature in obstructive sleep apnea. J Appl Physiol. 1996;81(2):643-52. doi: 10.1152/jappl.1996.81.2.643.
2. Ong AA et al. Efficacy of upper airway stimulation on collapse patterns observed during drug-induced sedation endoscopy. Otolaryngol Head Neck Surg. 2016;154(5):970-7. doi: 10.1177/0194599816636835.
3. Woodson BT et al. Three-year outcomes of cranial nerve stimulation for obstructive sleep apnea: The STAR trial. Otolaryngol Head Neck Surg. 2016;154(1):181-8. doi: 10.1177/0194599815616618.
4. Heiser C et al. Outcomes of upper airway stimulation for obstructive sleep apnea in a multicenter german postmarket study. Otolaryngol Head Neck Surg. 2017;156(2):378-84. doi: 10.1177/0194599816683378.
5. Gillespie MB et al. Upper airway stimulation for obstructive sleep apnea: Patient-reported outcomes after 48 months of follow-up. Otolaryngol Head Neck Surg. 2017;156(4):765-71. doi: 10.1177/0194599817691491.
6. Pietzsch JB et al. Long-term cost-effectiveness of upper airway stimulation for the treatment of obstructive sleep apnea: A model-based projection based on the star trial. Sleep. 2015;38(5):735-44. doi: 10.5665/sleep.4666.
7. Oliven A et al. Improved upper airway patency elicited by electrical stimulation of the hypoglossus nerves. Respiration. 1996;63(4):213-16. doi: 10.1159/000196547.
8. Strollo PJ et al. Upper-airway stimulation for obstructive sleep apnea. N Engl J Med. 2014;370(2):139-49. doi: 10.1056/NEJMoa1308659.
9. Liu YC et al. Palatopharyngoplasty resolves concentric collapse in patients ineligible for upper airway stimulation. Laryngoscope. Forthcoming.
10. De Andrade RGS et al. Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea. J Bras Pneumol. 2014;40(6):658-68. doi: 10.1590/S1806-37132014000600010
Clinical significance
Continuous positive airway pressure remains the gold standard and first-line treatment for moderate to severe OSA. When CPAP and other medical therapies fail or are poorly adopted, surgical solutions - either standalone or in unison - can be directed to target precision therapy.
The newest of these techniques is neuromodulation of the lingual musculature, particularly by way of selective stimulation of the hypoglossal nerve, which first demonstrated success in human clinical trials in 1996.1 Upper airway stimulation (UAS) was formally FDA-approved in 2014 (Inspire Medical Systems, Inc). UAS is designed to eliminate clinically significant OSA through stimulation of the anteriorly directed branches of the hypoglossal nerve, increasing the posterior airway space in a multilevel fashion.2 Since this time, over 7,500 patients have been treated with Inspire in nine countries (United States, Germany, The Netherlands, Switzerland, Belgium, Spain, France, Italy, and Finland). Prospective, international multicenter trials have demonstrated 68% to 96% clinical efficacy in well selected individuals. This is defined as a ≥ 50% reduction in the apnea hypopnea index (AHI) to an overall AHI of ≤ 20/hour.3,4 Additionally, post-UAS analysis demonstrates subjective reduction in daytime sleepiness as reported by Epworth sleepiness scores, with improvements in sleep-related quality of life. Further, UAS reduces socially disruptive snoring with 85% of bedpartners reporting soft to no snoring at 48-month follow-up.5 The procedure has also demonstrated long-term cost benefit in the US health-care system.6
Background and pathophysiology
Oliven and colleagues7 first observed the critical finding that selective intra-muscular stimulation of the genioglossus muscle lowered airway critical closing pressure (PCrit), thereby stabilizing the pharyngeal airway. Conversely, activation of the “retrusor” musculature, namely the hyoglossus and styloglossus muscles, increased Pcrit, increasing collapsibility of the pharyngeal airway.
Therapeutic implantation requires three incisions directed to the neck, chest, and right rib space (between the 4th to 6th intercostal spaces), with an operative time of 90 minutes or less in experienced hands. The majority of patients are discharged on the day of the procedure. Morbidity remains low with minimal pain reported during recovery. The most common complication is that of temporary tongue weakness, which typically resolves within 2 to 3 weeks. While very infrequent, patients should be counseled on the risk of postoperative hematoma, which can precipitate infection and subsequent explant of the device. Average recovery time spans between 3 and 7 days with activation of the device 4 weeks after surgical implantation to allow for appropriate tissue healing and reduce the risk of dislodgement of the implanted components. In contrast to other surgical treatment options, UAS is also reversible with no underlying alteration to existing pharyngeal anatomy apart from external incisions created during the procedure.
Stimulation to titration
As the need for a multidisciplinary approach to salvage of patients failing first-line therapy for OSA continues to grow, UAS with its multilevel impact continues to be of key interest. In similar fashion to established medical therapies such as PAP and oral appliance therapy (OAT), close observation between sleep medicine specialists and the implanting surgeon during the adaptation period with attention paid to titration parameters such as stimulation duration, pulse width, amplitude, and polarity, allow optimization of response outcome.
The stimulation electrode, which is designed in the form of a cuff to envelope the anterior (protrusor) branches of the hypoglossal nerve receives electrical stimulation from the implanted pulse generator, implanted above the pectoralis muscle of the chest wall. This design allows for collaborative awake and overnight titration of the device as directed by a sleep medicine physician. Attention is paid not only to the voltage “strength” administered with each pulse but also the degree of synchronization between respiration and stimulation, as well as pattern of pulse administration. Our experience remains that true success and adaptation to therapy requires not just meticulous surgical technique but a diligent approach to postoperative therapeutic titration to achieve a comfortable, yet effective, voltage for maintaining airway patency. Thus, akin to initiation of CPAP, UAS requires regular follow-up and device fine-tuning with patient comfort taken into consideration to achieve optimal results, and patient expectation should be aligned with this process.
Current indications
Success in UAS relies heavily on appropriate presurgical evaluation and clinical phenotyping. The following surgical indications have been demonstrated in the Stimulation Therapy for Apnea Reduction (STAR) trial and subsequent 3-year clinical follow-up: AHI between 15 and 80 events/hour (with ≤ 25% central apneas) and a BMI ≤ 32.8
As OSA often results from multi-level airway collapse, UAS targets an increase not only in the diameter of the retropalatal/oropharyngeal airway space but also the antero-posterior hypopharyngeal airway. Original criteria for implantation excluded patients with a pattern of complete circumferential collapse (CCC) noted on dynamic airway evaluation during pre-implant drug-induced sleep endoscopy (DISE). DISE aims to precisely target dynamic airway collapse patterns during simulated (propofol or midazolom induced) sleep.
Future directions
The effects of UAS are dependent on upper-airway cross-sectional area, particularly diameter. In patients who demonstrate CCC, the anteroposterior direction of activation derived from the UAS stimulus is unable to overcome CCC. In a recent prospective study, our group demonstrated that CCC can be converted to an airway collapse pattern compatible with UAS implantation, using a modified palatopharyngoplasty prior to UAS implantation. By stabilizing the lateral walls of the oropharyngeal airway with pre-implant palatal surgery, UAS is able to successfully direct widening of the airway cross-sectional area in an antero-posterior fashion. This exciting finding potentially allows for expansion of current indications, thus opening treatment to a wider patient population.9 Still, UAS remains highly studied in a relatively uniform patient population with data in more diverse subsets requiring further directed attention to expand and better define optimal patient populations for treatment.
From the perspective of improving patient adaptation and tolerance in UAS, a well-established concept in the CPAP literature can be applied, as explained by the Starling resistor model. The starling resistor is comprised of two rigid tubes connected by a collapsible segment in between. In parallel, the pharynx is a collapsible muscular tube connected on either end by the nose/nasal cavity and the trachea – both of which are bony/cartilaginous, noncollapsible structures. As has been shown in the use of CPAP, the same pressure required to maintain stability of the collapsible muscular pharynx via nasal breathing may lead to pharyngeal collapse when applied orally.10 This concept has also been directed towards UAS with our clinical experience demonstrating that oro or oronasal breathers tend to require a higher amplitude to maintain airway patency versus nasal breathers. This is an important area for future-directed study as medically/surgically improving nasal breathing in UAS subjects may subsequently lower amplitude requirements and improve patient tolerance.
Future direction to allow for improvement in the technology for application in a broader populational segment, external or alternative device powering mechanisms, along with MRI Compatibility and reducing the number of required external incisions will continue to broaden the patient selection criteria. As we move from a “stimulation” to a precision-tailored “stimulation and titration” approach, the mid to long term data supporting UAS remains very promising with 5-year follow up demonstrating sustained polysomnographic and subjective reported outcomes in well selected patients.
Dr. Awad is Assistant Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Northwestern University, Chicago, Illinois. Dr. Capasso is Associate Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Stanford Hospital and Clinics, Stanford, California.
References
1. Schwartz AR et al. Electrical stimulation of the lingual musculature in obstructive sleep apnea. J Appl Physiol. 1996;81(2):643-52. doi: 10.1152/jappl.1996.81.2.643.
2. Ong AA et al. Efficacy of upper airway stimulation on collapse patterns observed during drug-induced sedation endoscopy. Otolaryngol Head Neck Surg. 2016;154(5):970-7. doi: 10.1177/0194599816636835.
3. Woodson BT et al. Three-year outcomes of cranial nerve stimulation for obstructive sleep apnea: The STAR trial. Otolaryngol Head Neck Surg. 2016;154(1):181-8. doi: 10.1177/0194599815616618.
4. Heiser C et al. Outcomes of upper airway stimulation for obstructive sleep apnea in a multicenter german postmarket study. Otolaryngol Head Neck Surg. 2017;156(2):378-84. doi: 10.1177/0194599816683378.
5. Gillespie MB et al. Upper airway stimulation for obstructive sleep apnea: Patient-reported outcomes after 48 months of follow-up. Otolaryngol Head Neck Surg. 2017;156(4):765-71. doi: 10.1177/0194599817691491.
6. Pietzsch JB et al. Long-term cost-effectiveness of upper airway stimulation for the treatment of obstructive sleep apnea: A model-based projection based on the star trial. Sleep. 2015;38(5):735-44. doi: 10.5665/sleep.4666.
7. Oliven A et al. Improved upper airway patency elicited by electrical stimulation of the hypoglossus nerves. Respiration. 1996;63(4):213-16. doi: 10.1159/000196547.
8. Strollo PJ et al. Upper-airway stimulation for obstructive sleep apnea. N Engl J Med. 2014;370(2):139-49. doi: 10.1056/NEJMoa1308659.
9. Liu YC et al. Palatopharyngoplasty resolves concentric collapse in patients ineligible for upper airway stimulation. Laryngoscope. Forthcoming.
10. De Andrade RGS et al. Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea. J Bras Pneumol. 2014;40(6):658-68. doi: 10.1590/S1806-37132014000600010
Clinical significance
Continuous positive airway pressure remains the gold standard and first-line treatment for moderate to severe OSA. When CPAP and other medical therapies fail or are poorly adopted, surgical solutions - either standalone or in unison - can be directed to target precision therapy.
The newest of these techniques is neuromodulation of the lingual musculature, particularly by way of selective stimulation of the hypoglossal nerve, which first demonstrated success in human clinical trials in 1996.1 Upper airway stimulation (UAS) was formally FDA-approved in 2014 (Inspire Medical Systems, Inc). UAS is designed to eliminate clinically significant OSA through stimulation of the anteriorly directed branches of the hypoglossal nerve, increasing the posterior airway space in a multilevel fashion.2 Since this time, over 7,500 patients have been treated with Inspire in nine countries (United States, Germany, The Netherlands, Switzerland, Belgium, Spain, France, Italy, and Finland). Prospective, international multicenter trials have demonstrated 68% to 96% clinical efficacy in well selected individuals. This is defined as a ≥ 50% reduction in the apnea hypopnea index (AHI) to an overall AHI of ≤ 20/hour.3,4 Additionally, post-UAS analysis demonstrates subjective reduction in daytime sleepiness as reported by Epworth sleepiness scores, with improvements in sleep-related quality of life. Further, UAS reduces socially disruptive snoring with 85% of bedpartners reporting soft to no snoring at 48-month follow-up.5 The procedure has also demonstrated long-term cost benefit in the US health-care system.6
Background and pathophysiology
Oliven and colleagues7 first observed the critical finding that selective intra-muscular stimulation of the genioglossus muscle lowered airway critical closing pressure (PCrit), thereby stabilizing the pharyngeal airway. Conversely, activation of the “retrusor” musculature, namely the hyoglossus and styloglossus muscles, increased Pcrit, increasing collapsibility of the pharyngeal airway.
Therapeutic implantation requires three incisions directed to the neck, chest, and right rib space (between the 4th to 6th intercostal spaces), with an operative time of 90 minutes or less in experienced hands. The majority of patients are discharged on the day of the procedure. Morbidity remains low with minimal pain reported during recovery. The most common complication is that of temporary tongue weakness, which typically resolves within 2 to 3 weeks. While very infrequent, patients should be counseled on the risk of postoperative hematoma, which can precipitate infection and subsequent explant of the device. Average recovery time spans between 3 and 7 days with activation of the device 4 weeks after surgical implantation to allow for appropriate tissue healing and reduce the risk of dislodgement of the implanted components. In contrast to other surgical treatment options, UAS is also reversible with no underlying alteration to existing pharyngeal anatomy apart from external incisions created during the procedure.
Stimulation to titration
As the need for a multidisciplinary approach to salvage of patients failing first-line therapy for OSA continues to grow, UAS with its multilevel impact continues to be of key interest. In similar fashion to established medical therapies such as PAP and oral appliance therapy (OAT), close observation between sleep medicine specialists and the implanting surgeon during the adaptation period with attention paid to titration parameters such as stimulation duration, pulse width, amplitude, and polarity, allow optimization of response outcome.
The stimulation electrode, which is designed in the form of a cuff to envelope the anterior (protrusor) branches of the hypoglossal nerve receives electrical stimulation from the implanted pulse generator, implanted above the pectoralis muscle of the chest wall. This design allows for collaborative awake and overnight titration of the device as directed by a sleep medicine physician. Attention is paid not only to the voltage “strength” administered with each pulse but also the degree of synchronization between respiration and stimulation, as well as pattern of pulse administration. Our experience remains that true success and adaptation to therapy requires not just meticulous surgical technique but a diligent approach to postoperative therapeutic titration to achieve a comfortable, yet effective, voltage for maintaining airway patency. Thus, akin to initiation of CPAP, UAS requires regular follow-up and device fine-tuning with patient comfort taken into consideration to achieve optimal results, and patient expectation should be aligned with this process.
Current indications
Success in UAS relies heavily on appropriate presurgical evaluation and clinical phenotyping. The following surgical indications have been demonstrated in the Stimulation Therapy for Apnea Reduction (STAR) trial and subsequent 3-year clinical follow-up: AHI between 15 and 80 events/hour (with ≤ 25% central apneas) and a BMI ≤ 32.8
As OSA often results from multi-level airway collapse, UAS targets an increase not only in the diameter of the retropalatal/oropharyngeal airway space but also the antero-posterior hypopharyngeal airway. Original criteria for implantation excluded patients with a pattern of complete circumferential collapse (CCC) noted on dynamic airway evaluation during pre-implant drug-induced sleep endoscopy (DISE). DISE aims to precisely target dynamic airway collapse patterns during simulated (propofol or midazolom induced) sleep.
Future directions
The effects of UAS are dependent on upper-airway cross-sectional area, particularly diameter. In patients who demonstrate CCC, the anteroposterior direction of activation derived from the UAS stimulus is unable to overcome CCC. In a recent prospective study, our group demonstrated that CCC can be converted to an airway collapse pattern compatible with UAS implantation, using a modified palatopharyngoplasty prior to UAS implantation. By stabilizing the lateral walls of the oropharyngeal airway with pre-implant palatal surgery, UAS is able to successfully direct widening of the airway cross-sectional area in an antero-posterior fashion. This exciting finding potentially allows for expansion of current indications, thus opening treatment to a wider patient population.9 Still, UAS remains highly studied in a relatively uniform patient population with data in more diverse subsets requiring further directed attention to expand and better define optimal patient populations for treatment.
From the perspective of improving patient adaptation and tolerance in UAS, a well-established concept in the CPAP literature can be applied, as explained by the Starling resistor model. The starling resistor is comprised of two rigid tubes connected by a collapsible segment in between. In parallel, the pharynx is a collapsible muscular tube connected on either end by the nose/nasal cavity and the trachea – both of which are bony/cartilaginous, noncollapsible structures. As has been shown in the use of CPAP, the same pressure required to maintain stability of the collapsible muscular pharynx via nasal breathing may lead to pharyngeal collapse when applied orally.10 This concept has also been directed towards UAS with our clinical experience demonstrating that oro or oronasal breathers tend to require a higher amplitude to maintain airway patency versus nasal breathers. This is an important area for future-directed study as medically/surgically improving nasal breathing in UAS subjects may subsequently lower amplitude requirements and improve patient tolerance.
Future direction to allow for improvement in the technology for application in a broader populational segment, external or alternative device powering mechanisms, along with MRI Compatibility and reducing the number of required external incisions will continue to broaden the patient selection criteria. As we move from a “stimulation” to a precision-tailored “stimulation and titration” approach, the mid to long term data supporting UAS remains very promising with 5-year follow up demonstrating sustained polysomnographic and subjective reported outcomes in well selected patients.
Dr. Awad is Assistant Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Northwestern University, Chicago, Illinois. Dr. Capasso is Associate Professor – Department of Otolaryngology/Head & Neck Surgery, and Chief – Division of Sleep Surgery; Stanford Hospital and Clinics, Stanford, California.
References
1. Schwartz AR et al. Electrical stimulation of the lingual musculature in obstructive sleep apnea. J Appl Physiol. 1996;81(2):643-52. doi: 10.1152/jappl.1996.81.2.643.
2. Ong AA et al. Efficacy of upper airway stimulation on collapse patterns observed during drug-induced sedation endoscopy. Otolaryngol Head Neck Surg. 2016;154(5):970-7. doi: 10.1177/0194599816636835.
3. Woodson BT et al. Three-year outcomes of cranial nerve stimulation for obstructive sleep apnea: The STAR trial. Otolaryngol Head Neck Surg. 2016;154(1):181-8. doi: 10.1177/0194599815616618.
4. Heiser C et al. Outcomes of upper airway stimulation for obstructive sleep apnea in a multicenter german postmarket study. Otolaryngol Head Neck Surg. 2017;156(2):378-84. doi: 10.1177/0194599816683378.
5. Gillespie MB et al. Upper airway stimulation for obstructive sleep apnea: Patient-reported outcomes after 48 months of follow-up. Otolaryngol Head Neck Surg. 2017;156(4):765-71. doi: 10.1177/0194599817691491.
6. Pietzsch JB et al. Long-term cost-effectiveness of upper airway stimulation for the treatment of obstructive sleep apnea: A model-based projection based on the star trial. Sleep. 2015;38(5):735-44. doi: 10.5665/sleep.4666.
7. Oliven A et al. Improved upper airway patency elicited by electrical stimulation of the hypoglossus nerves. Respiration. 1996;63(4):213-16. doi: 10.1159/000196547.
8. Strollo PJ et al. Upper-airway stimulation for obstructive sleep apnea. N Engl J Med. 2014;370(2):139-49. doi: 10.1056/NEJMoa1308659.
9. Liu YC et al. Palatopharyngoplasty resolves concentric collapse in patients ineligible for upper airway stimulation. Laryngoscope. Forthcoming.
10. De Andrade RGS et al. Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea. J Bras Pneumol. 2014;40(6):658-68. doi: 10.1590/S1806-37132014000600010