Hypoglossal nerve stimulation improves obstructive sleep apnea: 12-month outcomes

SUMMARY Reduced upper airway muscle activity during sleep is a key contributor to obstructive sleep apnoea pathogenesis. Hypoglossal nerve stimulation activates upper airway dilator muscles, including the genioglossus, and has the potential to reduce obstructive sleep apnoea severity. The objective of this study was to examine the safety, feasibility and efficacy of a novel hypoglossal nerve stimulation system (HGNS � ; Apnex Medical, St Paul, MN, USA) in treating obstructive sleep apnoea at 12 months following implantation. Thirty-one subjects (35% female, age 52.4 9.4 years) with moderate to severe obstructive sleep apnoea and unable to tolerate positive airway pressure underwent surgical implantation and activation of the hypoglossal nerve stimulation system in a prospective single-arm interventional trial. Primary outcomes were changes in obstructive sleep apnoea severity (apnoea–hypopnoea index, from in-laboratory polysomnogram) and sleep-related quality of life [Functional Outcomes of Sleep Questionnaire (FOSQ)]. Hypoglossal nerve stimulation was used on 86 16% of nights for 5.4 1.4 h per night. There was a significant improvement (P < 0.001) from baseline to 12 months in apnoea–hypopnoea index (45.4 17.5 to 25.3 20.6 events h 1 ) and Functional Outcomes of Sleep Questionnaire score (14.2 2.0 to 17.0 2.4), as well as other polysomnogram and symptom measures. Outcomes were stable compared with 6 months following implantation. Three serious device-related adverse events occurred: an infection requiring device removal; and two stimulation lead cuff dislodgements requiring replacement. There were no significant adverse events with onset later than 6 months following implantation. Hypoglossal nerve stimulation demonstrated favourable safety, feasibility and efficacy.