Safety and Effectiveness of Upper Airway Stimulation via the Hypoglossal Nerve for Obstructive Sleep Apnea

Abstract

Objectives:

Determine safety and effectiveness of upper airway stimulation for treatment of obstructive sleep apnea (OSA) in a prospective, multi-center trial; with subsequent randomized, controlled therapy withdrawal evaluation.

Methods:

This study enrolled and screened 900 adult subjects. Inclusion criteria were moderate-to-severe OSA (apnea-hypopnea index [AHI] 20-50), prior continuous positive airway pressure (CPAP) failure or intolerance, and body mass index (BMI) < 32. All qualified subjects underwent further screening with drug-induced sleep endoscopy (DISE) to exclude those with concentric palatal collapse. 126 subjects meeting all inclusion/exclusion criteria then underwent surgical implantation of a right sided unilateral hypoglossal nerve stimulation electrode, with pulse generator and respiration sensor (Upper Airway Stimulation System, Inspire Medical Systems, Minnesota). Patients were evaluated at 2, 6, and 12 months. Primary outcome measures included AHI, oxygen desaturation index, Epworth Sleepiness Scale, and Functional Outcomes of Sleep Questionnaire at 12 months. Therapy withdrawal effect was evaluated by randomizing a subset of consecutive responders to one week of on or off therapy for controlled comparison.

Results:

All 126 subjects were successfully implanted. In general, subjects were middle aged (mean 54.5 ± 10.2 yrs), male (83%), with severe OSA (mean baseline AHI 32.0 ± 11.8). Transient dysarthria and dysphagia were noted in a minority of patients. Over 70% of subjects have completed the study, with the remaining scheduled to complete 12 month evaluation by April, 2013. Final safety and effectiveness outcomes will be presented.

Conclusions:

Implantation of an upper airway stimulation system involving unilateral hypoglossal nerve electrode placement appears safe and feasible, with transient dysarthria occurring infrequently. Effectiveness will be addressed after completion of 12 month follow-up for all subjects.