Up versus down: Does cuff spine orientation affect early adherence to upper airway stimulation?

Purpose Upper airway stimulation (UAS) is a treatment option for moderate-to-severe OSA, in which electrical stimulation is applied to the hypoglossal nerve via an electrode cuff. In this study, we assess the effect of electrode cuff positioning on UAS outcomes, in particular device adherence. Methods Patients at a single academic institution who met the Food and Drug Administration criteria for UAS between 2016 and 2021 were included. The electrode position was documented as superior (cuff spine up) or inferior (cuff spine down) to the hypoglossal nerve based on postoperative lateral neck X-ray. Patients underwent titration polysomnography 2–6 months following surgery. The most recent postoperative variables from sleep studies following titration polysomnogram were used for statistical analysis. Adherence data was downloaded from the UAS device. Results 327 patients met inclusion criteria. The average age of patients was 60.9 ± 11.1 years, with 105 (32.1%) females. Cuff spine up position was present in 169 (51.7%) patients as compared to 158 (48.3%) with cuff spine down. UAS adherence was significantly higher among cuff spine down patients (45.4 vs. 41.0 h device use/week, p = 0.015). Cuff position was not significantly associated with therapeutic amplitude, change in apnea hypopnea index, or change in symptoms as measured by the Epworth Sleepiness Scale. On multivariable linear regression analysis, cuff spine down position ( β = 3.7, CI [1.3, 7.4], p = 0.038) and increased age ( β = 0.22, CI [0.07, 0.38], p = 0.005) were associated with increased adherence. Conclusions UAS cuff spine down position is associated with increased device adherence. Further investigation into cuff positioning is warranted.