Outcomes of Hypoglossal Nerve Stimulator Implant in Obstructive Sleep Apnea Patients with Higher Apnea-hypopnea Indices

Introduction: Hypoglossal nerve stimulator (HGNS) implantation is an effective treatment for moderate-to-severe obstructive sleep apnea (OSA). Current guidelines exclude patients with severe OSA (apnea-hypopnea index [AHI] >65) from receiving HGNS, leaving a gap in treatment options. This study investigates whether patients with baseline AHI above 65 derive clinical benefit from HGNS.

Methods: We conducted a retrospective review of patients undergoing HGNS implantation at a single academic center. Patient demographics, comorbidities, and pre- and post-operative AHI at 3, 6, and 12 months were collected. Paired t-tests and Wilcoxon signed-rank tests were used to assess changes in AHI using RStudio.

Results: 218 patients were identified for analysis; 204 had baseline AHI ≤65, and 14 had baseline AHI >65. At 3 months post-implantation, the >65 AHI cohort had a mean AHI reduction of 51.3%, comparable to the ≤65 cohort (55.8%, p=0.728). By 6 months, the >65 AHI cohort’s mean AHI reduction decreased to 30.5%, and 38.5% in the ≤65 AHI group (p=0.599). Wilcoxon signed-rank tests at 3 months revealed p-values of 0.0156 and < 0.01 in the >65 AHI and ≤65 AHI groups respectively, and at 6 months, p-values were 0.25 and < 0.01 respectively.

Conclusions: Patients with baseline AHI above 65 demonstrate significant short-term improvement following HGNS implantation, but this benefit appears to wane by 6 months. These results suggest HGNS may provide limited long-term benefit for the highest-severity OSA patients, highlighting the need for additional strategies or closer follow-up in this population.