Bilateral Hypoglossal Nerve Stimulation for Treatment of Adult Obstructive Sleep Apnea.

Background and aim: Hypoglossal nerve stimulation (HNS) decreases obstructive sleep apnoea (OSA) severity via genioglossus muscle activation and decreased upper airway collapsibility. This study assessed the safety and effectiveness at 6 months post-implantation of a novel device delivering bilateral HNS via a small implanted electrode activated by a unit worn externally, to treat OSA: the GenioT system. Methods: This prospective, open-label, non-randomised, single-arm treatment study was conducted at eight centres in three countries (Australia, France and the UK). Primary outcomes were incidence of device-related serious adverse events and change in the apnoea-hypopnoea index (AHI). The secondary outcome was the change in the 4% oxygen desaturation index (ODI). Additional outcomes included measures of sleepiness, quality of life, snoring and device use. This trial was registered with ClinicalTrials.gov, number NCT03048604. Results: 22 out of 27 implanted participants (63% male, aged 55.9 +/- 12.0 years, body mass index (BMI) 27.4 +/- 3.0 kg.m(-2)) completed the protocol. At 6 months BMI was unchanged ( p=0.85); AHI decreased from 23.7 +/- 12.2 to 12.9 +/- 10.1 events.h(-1), a mean change of 10.8 events.h(-1) ( p<0.001); and ODI decreased from 19.1 +/- 11.2 to 9.8 +/- 6.9 events.h(-1), a mean change of 9.3 events.h(-1) ( p<0.001). Daytime sleepiness (Epworth Sleepiness Scale; p=0.01) and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire-10; p=0.02) both improved significantly. The number of bed partners reporting loud, very intense snoring, or leaving the bedroom due to participant snoring decreased from 96% to 35%. 91% of participants reported device use >5 days per week, and 77% reported use for >5 h per night. No device-related serious adverse events occurred during the 6-month post-implantation period. Conclusions: Bilateral HNS using the GenioT system reduces OSA severity and improves quality of life without device-related complications. The results are comparable with previously published HNS systems despite minimal implanted components and a simple stimulation algorithm.