Rationale Patient selection for hypoglossal nerve stimulation (HGNS) for obstructive sleep apnea (OSA) requires assessment of pharyngeal site of collapse using drug-induced sleep endoscopy (DISE). Objectives The current study aims to address two key knowledge gaps: First, we prospectively confirm that, among HGNS candidates, reduced HGNS efficacy is associated with oropharyngeal lateral wall (OLW) collapse (Aim 1). Second, given DISE is resource-intensive procedure and delays treatment, we evaluate whether a recently-developed non-invasive method for identifying OLW collapse using airflow shapes is associated with reduced HGNS efficacy (Aim 2). Methods Patients who underwent DISE, HGNS implantation, and follow-up sleep testing were included in Aim 1 (n=369) as part of an observational cohort study. For Aim 2, airflow data estimating OLW collapse probability were collected during DISE via pneumotachograph (n=138, DISE Flow cohort); and from a home sleep test via nasal cannula for validation (n=46, HST cohort). Linear regression quantified associations between HGNS efficacy (%reduction in AHI) and DISE-determined OLW collapse (Aim 1) or flow-shape-determined OLW collapse (probability score per 2SD; Aim 2), adjusting for baseline AHI. Results Compared to non-OLW collapse, DISE-determined OLW collapse reduced HGNS efficacy 95%CI by ‒18.0‒31.9,‒6.2%. Increased flow-shape-determined OLW collapse probability (Δ2SD) was associated with reduced HGNS efficacy in both DISE Flow (‒24.8 ‒40.4, ‒11.7%) and HST (‒22.7 ‒50.0, ‒2.6%) cohorts. Conclusion This study prospectively validates OLW collapse as a key factor in HGNS failure and shows that airflow-based identification of OLW collapse can effectively estimate HGNS efficacy, representing a significant advancement in patient selection for HGNS.
Vena et al. (Thu,) studied this question.