Transoral Versus Endoscopic Examination in Predicting Outcomes of Hypoglossal Nerve Stimulation for Obstructive Sleep...

To examine the correlation between transoral and awake endoscopic examination and investigate their respective ability to predict outcomes of hypoglossal nerve stimulation (HGNS).

Retrospective cohort study at a US medical center.

Subjects were adults with apnea-hypopnea index (AHI) >15 events/hr who underwent HGNS according to standard indications. Eligible subjects had diagnostic preoperative sleep studies, full-night efficacy postoperative studies, as well as postoperative video recordings of transoral examination and awake endoscopy. Recordings were independently scored by two blinded reviewers. Cohen's κ coefficient, Student t test, and χ² analyses were performed.

Fifty-seven patients met all inclusion criteria. On average, patients were Caucasian, middle aged, and overweight. The mean preoperative AHI was 36.7 events/hr, which improved significantly to 18.3 events/hr following HGNS (P < .01). Overall, the response rate (defined as AHI reduction >50% and AHI < 20 events/hr) was 49%. There was slight correlation between transoral tongue protrusion and endoscopic tongue base movement (κ = 0.10). On transoral examination, patients with minimal/moderate tongue motion achieved a greater mean AHI reduction than patients with full motion (26.0 ± 18.0 vs. 12.8 ± 24.1, P = .02). In contrast, on awake endoscopy, patients with minimal/moderate tongue motion achieved a lesser mean AHI reduction than patients with full motion (8.7 ± 19.9 vs. 22.1 ± 22.7, P = .04).

Transoral tongue protrusion bears an inverse relationship to HGNS success and correlates poorly with endoscopic tongue base movement. Endoscopic tongue base motion appears reflective of response to HGNS, with greater motion corresponding to greater AHI reduction.

4 Laryngoscope, 131:675-679, 2021.