0589 Evaluating the Impact of Sleep Position on Efficacy of Hypoglossal Nerve Stimulation

Abstract Introduction Current literature supports hypoglossal nerve stimulation (HNS) as a treatment option for select patients with moderate-to-severe obstructive sleep apnea (OSA). However, in about a third of implanted patients, HNS is ineffective. To date, few publications have investigated how sleep position impacts HNS efficacy. In 2019, the Stanford group found that HNS had a greater impact on non-supine AHI vs supine AHI; the data was limited to eleven patients monitored in the sleep lab and did not incorporate full-night data. We explored the effect of sleep position on HNS efficacy in a larger sample by comparing pre- and post-operative overnight sleep studies. Methods We performed a retrospective chart review of 136 patients implanted at Mount Sinai Hospital from 2016-2023. Patients were included if they tolerated therapeutic voltage and completed pre- and post-operative sleep studies with at least 30 minutes of supine and non-supine sleep. Mean differences in pre- and post-operative overall AHI4% (DeltaAHI), supine AHI4% (DeltaSupine) and non-supine AHI4% (DeltaNon-supine) were calculated. Paired T-Test was then performed to compare AHI4% percent reduction when supine versus non-supine. Secondary outcomes included mean difference in pre- and post-operative ODI4 (DeltaODI) and ESS (DeltaESS). We also calculated our cohort’s surgical success rate, as defined by Sher’s criteria. Results Seventeen patients met inclusion criteria. Mean age was 60.2+/-11.2 years, and 15 patients were male (88.2%). Mean BMI was 29.1+/-3.0 kg/m2. Mean preoperative AHI4% was 29.4+/-14.8 events/hour; mean preoperative supine AHI4% and non-supine AHI4% were 44.6 events/hour and 13.3 events/hour respectively. Overall DeltaAHI was 15.2 events/hour (p=0.0004), DeltaSupine was 21.4 events/hour (p=0.0071), and DeltaNon-supine was 6.2 events/hour (p=0.0486). Despite the difference in absolute reduction, there was no statistically significant difference (p=0.3242) between the percent reduction of supine AHI4% (41.7%) versus non-supine AHI4% (10.0%). Mean differences for DeltaODI and DeltaESS were 11.5 (p=0.0051) and 2.9 (p=0.2) respectively. Overall success rate was 58.8% (10 of 17 patients), which is similar to other studies in the literature. Conclusion In our sample, we found no difference in AHI percent reduction between supine and non-supine position, suggesting that HNS is effective in improving OSA regardless of positionality. Support (if any) NCATS: TL1TR004420;