(388) Post-Operative Intolerance Predicts Inferior Outcomes in Hypoglossal Nerve Stimulator Patients

Introduction: There is a subgroup of obstructive sleep apnea (OSA) patients that are initially intolerant to hypoglossal nerve stimulator (HGNS) therapy, ultimately requiring in-office adjustment of the device. Our study looks to delve into the relationship between the need for early post-operative HGNS adjustment and long-term surgical sleep outcomes.

Methods: This was a single-center, retrospective study. Patients who underwent HGNS placement for OSA from January 2020 to December 2021 were reviewed. Adjustment visits were defined as any visit that occurred before post-operative sleep study was performed and after initial activation of the device, that included modification of the HGNS device settings (stimulation voltage, configuration, pulse width, rate, start and/or pause delay). The primary outcome measures included were post-operative AHI and O2 nadir. Secondary aims were to test for the association between rates of psychiatric disorders, insomnia, fibromyalgia, increased BMI and rates of adjustment visits.

Results: 117 patients underwent HGNS placement and 30 (25.6%) of those patients underwent post-operative adjustment. Patients that underwent adjustment demonstrated a higher average post-operative AHI of 21.3, whereas those who did not undergo adjustment averaged 12.5 (p=0.002). Adjustment patients also averaged significantly lower post-operative O2 nadir compared to non-adjustment patients (82% vs 85%; p=0.009). Those who required adjustment visits had higher baseline BMI than those who did not (29.4 vs 28.3 (p=0.047), while history of psychiatric disorders, insomnia, and fibromyalgia were not associated with higher rates of adjustment visits.

Conclusions: Patients with early post-operative HGNS intolerance requiring adjustment of the device have significantly inferior long-term surgical sleep outcomes for OSA. In-depth study is needed to determine the nature of this discrepancy and why this cohort of patients performed poorly compared to patients who did not need post-operative adjustment.