Combination Tonsillectomy and Hypoglossal Nerve Stimulation for OSA Patients With Lateral Pharyngeal Collapse

The goal of this clinical trial is to learn whether removing the tonsils at the time of hypoglossal nerve stimulation improves treatment of obstructive sleep apnea in adults whose airway collapses from the side of the upper airway during sleep. The main questions it aims to answer are: 1. Does hypoglossal nerve stimulation combined with tonsillectomy reduce the severity of obstructive sleep apnea more than hypoglossal nerve stimulation alone? 2. Does tonsillectomy improve how effectively hypoglossal nerve stimulation opens and stabilizes the upper airway? Researchers will compare participants who receive hypoglossal nerve stimulation with tonsillectomy to participants who receive hypoglossal nerve stimulation alone. Participants will: * Complete sleep studies, questionnaires, and other assessments before and after treatment * Be randomly assigned to receive hypoglossal nerve stimulation either with or without tonsillectomy * Return for follow-up visits and sleep testing to evaluate treatment effectiveness * In a subset of participants, complete additional overnight testing to measure how treatment changes upper-airway collapsibility

Inclusion Criteria: * Age ≥ 18 years * Diagnosis of obstructive sleep apnea with apnea-hypopnea index (AHI) ≥ 15 events/hour * Complete oropharyngeal lateral wall (OPLW) collapse identified on DISE * Candidate for HGNS implantation based on standard clinical criteria * Presence of small (1-2+) tonsils and eligibility for tonsillectomy * Untreated OSA at the time of enrollment * Willing and able to provide written informed consent Exclusion Criteria: * Absence of tonsils * Presence of large tonsils (3-4+; not eligible for HGNS) * Predominant central or mixed sleep apnea (\>25% central or mixed events) * Any unstable or serious medical condition that, in the opinion of the investigator, would increase risk or interfere with study participation * Ineligibility for HGNS implantation based on standard clinical or surgical criteria * Inability to comply with study procedures or follow-up assessments