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

Obstructive sleep apnea (OSA) is commonly treated with hypoglossal nerve stimulation (HGNS), but treatment efficacy is substantially reduced in patients with complete oropharyngeal lateral wall (OPLW) collapse. HGNS primarily enlarges the airway by protruding the tongue and is therefore most effective in patients with anteroposterior patterns of airway collapse. Tonsillectomy reduces tissue contributing to lateral pharyngeal narrowing and may complement the mechanism of HGNS by addressing residual lateral wall obstruction. Preliminary clinical data suggest that combining tonsillectomy with HGNS substantially improves treatment response compared with HGNS alone in patients with OPLW collapse, but this strategy has not been evaluated in a randomized clinical trial.

This prospective, randomized controlled trial will enroll 72 adults with moderate-to-severe OSA, complete OPLW collapse identified on drug-induced sleep endoscopy, and candidacy for both HGNS implantation and tonsillectomy. Participants will be randomized 1:1 to receive either concurrent HGNS implantation plus tonsillectomy or HGNS implantation alone. All participants will undergo standard postoperative device activation and titration. The primary efficacy endpoint will be assessed after approximately one month of optimized HGNS therapy using sleep studies and patient-reported outcomes. Participants in the HGNS-alone group with persistent OSA may subsequently undergo delayed tonsillectomy as part of standard clinical care, permitting additional within-subject mechanistic comparisons.

The primary objective is to determine whether concurrent tonsillectomy improves the effectiveness of HGNS in reducing OSA severity compared with HGNS alone. Secondary objectives are to determine whether tonsillectomy enhances HGNS-induced improvements in upper-airway collapsibility and to evaluate whether tonsillectomy modifies the physiological effects of HGNS beyond the effects of either treatment alone. In an optional mechanistic substudy, approximately 30 participants will undergo detailed physiological sleep studies to measure pharyngeal collapsibility using gold-standard techniques, providing insight into the mechanisms underlying any observed improvement in clinical outcomes.

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