HSC Section 3 - Trauma, Critical Care and Sleep Medicine

Reprinted by permission of Laryngoscope. 2016; 126 Suppl 7:S5-S8.

The Laryngoscope V C 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Upper Airway Stimulation Therapy: A Novel Approach to Managing Obstructive Sleep Apnea

Ryan J. Soose, MD; M. Boyd Gillespie, MD, MSc

Objectives: Review the role of upper airway stimulation (UAS) therapy in the management of moderate to severe obstructive sleep apnea (OSA). Data Sources: A literature search was performed of PubMed and Medline using the search terms clinical trial; obstruc- tive sleep apnea; upper airway stimulation; hypoglossal stimulation; hypoglossal nerve; Inspire; and ImThera. Review Methods: All published clinical trials of currently available devices were reviewed. Unpublished data were excluded. Results: UAS therapy results in surgical success (AHI decrease of > 50% and overall AHI < 5 20) in 66% of implanted subjects. In addition, UAS therapy results in significant improvement in daytime sleepiness, snoring, and sleep-related quality of life. Conclusion: UAS therapy is a valid alternative for select patients with moderate to severe OSA who are unsuccessful users of CPAP therapy. Key Words: Upper airway stimulation, obstructive sleep apnea, sleep medicine. Laryngoscope , 126:S5–S8, 2016

INTRODUCTION Obstructive sleep apnea (OSA) is an increasingly common disorder that affects an estimated 5% to 10% of the US adult population. OSA causes significant reduc- tion in the quality of life of OSA patients and their part- ners due to poor quality sleep, chronic snoring, daytime sleepiness and fatigue, and effects on memory and cogni- tion. OSA also has strong associations with hyperten- sion, 1,2 type II diabetes, 3,4 stroke, 5–7 congestive heart failure, 8,9 coronary artery disease, 10–12 and premature death. 13,14 OSA remains underdiagnosed, with only 40% of those with OSA currently diagnosed. 15,16 In addition, for those who are diagnosed, treatment is frequently not utilized, is suboptimal, or is outright ineffective. Continuous positive airway pressure (CPAP) is current- ly considered the gold standard of treatment for OSA due to evidence that CPAP improves sleep quality, reduces the risk of OSA-related comorbidities, and improves patient quality of life. 11,17–19 Although CPAP has undergone numerous tech- nological advances, patient compliance remains a significant From the Department of Otolaryngology–Head and Neck Surgery ( R . S .), University of Pittsburgh, Pittsburgh, Pennsylvania; and the Department of Otolaryngology–Head and Neck Surgery ( M . B . G .), Medical University of South Carolina, Charleston, South Carolina, U.S.A. Editor’s Note: This Manuscript was accepted for publication July 25, 2016. Dr. Soose has served as a consultant and study investigator (research support) for Inspire Medical Systems. Dr. Gillespie received honoraria from Inspire Medical Systems for a panel discussion. The authors have no other funding, financial relationships, or conflicts of interest to disclose. Send correspondence to M. Boyd Gillespie, MD, Department of Otolaryngology–Head and Neck Surgery, 135 Rutledge Avenue, MSC 550, Charleston, SC 29425-5500. E-mail: gillesmb@musc.edu

problem, with 40% to 70% of patients using CPAP less than a therapeutic amount of time. 20,21 Upper airway surgery is an option for patients with symptomatic OSA who are unable to adhere to CPAP ther- apy. A multilevel surgical approach is preferred, because most moderate to severe OSA patients have airway col- lapse at multiple sites. 22 Multilevel surgery includes a range of procedures that both enlarge the lumen and reduce the collapsibility of the upper airway. Surgical treatment of OSA can be effective for some properly select- ed patients, but overall, results are equivocal. In addition to mixed results, OSA surgeries often involve high morbid- ity, long recovery times, and low patient acceptance. 23–25 Additionally, published data for OSA surgeries are based primarily on less scientifically rigorous case series data. 24,26 Given the compliance problems with CPAP and the mediocre results of surgical treatment, novel treatment options to reduce the risk of dangerous comorbidities and to improve quality of life for people suffering from OSA are indicated. A potential limitation of traditional surgical approaches for OSA is the focus on reducing soft tissue obstruction in the upper airway by excising redundant soft tissue. Although this approach works for select patients, it fails to address the underlying increase in air- way collapsibility caused by reduced neuromuscular tone, which is thought to be the primary pathophysiological basis for OSA. 27,28 The genioglossus muscle is the primary upper airway dilator muscle, and in normal healthy sub- jects it responds to negative intraluminal pressure with a corresponding increase in genioglossus electromyographic activity. This negative pressure reflex appears to be dys- functional in many patients with OSA. 28 The etiology of the neuromuscular dysfunction in OSA is unclear but may

DOI: 10.1002/lary.26258

Soose and Gillespie: Upper Airway Stimulation Therapy

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