Right Versus Left Cuff Position for Upper Airway Stimulation

Upper airway stimulation (UAS) is a treatment option for obstructive sleep apnea in which electrical stimulation is applied to the hypoglossal nerve. Nerve branches that control tongue protrusion are located inferiorly. Due to positioning, left-sided implants are typically placed with an inferiorly oriented electrode cuff (L-down) as opposed to superiorly on the right (R-up). In this study, we assess the impact of left- versus right-sided UAS on patient outcomes.

Retrospective cohort study.

Tertiary Academic Medical Center.

Patients who underwent UAS implantation between 2016 and 2021 with an L-down or R-up oriented cuff as confirmed by X-ray were included. Data were collected retrospectively. Most recent sleep study variables were used for analysis.

A total of 190 patients met the inclusion criteria. The average age was 61.0 ± 11.0 years, with 55 (28.9%) females. L-down orientation was present in 21 (11.1%) patients vs 169 (88.9%) R-up. Indications for L-down included hunting/shooting (n = 15), prior radiation/surgery (n = 4), central port (n = 1), and brachial plexus injury (n = 1). Adherence was higher among L-down patients (47.1 vs 41.0 hours use/week, P = .037) in univariate analysis, with a similar time to adherence data collection (4.4 vs 4.2 months, P = .612), though this finding was not maintained in the multivariate regression analysis. Decrease in apnea-hypopnea index (21.3 vs 22.8, P = .734), treatment success (76.5% vs 84.0%, P = .665), functional threshold (1.5 vs 1.6, P = .550), therapeutic amplitude (2.3 vs 2.4, P = .882), and decrease in Epworth Sleepiness Scale (4.9 vs 2.6, P = .060) were not significantly different between cohorts.

This study is the first to examine the orientation of the UAS electrode cuff concerning the electrodes' natural position and the potential effect on postoperative outcomes. Our study found no significantly different treatment outcomes between the L-down versus R-up cohort, with the exception of device adherence, which was significantly higher in the L-down group on univariate analysis though not on multivariate analysis. Future studies with larger patient cohorts are needed to further investigate this potential relationship between treatment outcomes and electrode cuff orientation.