(520) UAS as a salvage procedure for persistent OSA after ESP

Introduction: The efficacy of an upper airway stimulation (UAS) for persistent obstructive sleep apnea (OSA) in patients who have undergone expansion sphincter pharyngoplasty (ESP) is unclear. Additionally, the evidence for ESP as a rescue procedure in UAS non-response is limited. In this study, we investigated if there is a difference in the outcome of patients who underwent UAS followed by ESP with those who underwent ESP followed by UAS.

Methods: This study is a retrospective, single-institution review of patients who underwent both ESP and UAS. Patients were grouped into ESP-first or UAS-first groups. Sleep study data prior to and after the first and second surgery were collected. Surgical success was defined as a decrease in post-operative apnea-hypopnea index (AHI) ≤50% and ≤20 events/hour. Pre- and post-operative Drug-Induced Sleep Endoscopy (DISE) were compared when available. All statistical analysis was performed in R Studio using an alpha level of 0.05.

Results: We identified 20 ESP-first patients and 8 UAS-first patients. No significant differences in gender, age, or pre-operative BMI were found between groups. Pre-and post-operative AHI after their first surgery was 39.85±17.72 and 29.72±15.94 in the ESP-first group, and 36.29±13.69 and 37.85 ±23.45 in the UAS-first group. The final AHI and treatment success after UAS in the ESP-first group was 19.65±17.59 and 47%, compared to 36.6±27.66 and 20% in the UAS-first group after ESP. Changes in DISE in the ESP-first group were notable for improved lateral oropharyngeal wall collapse (p = 0.005) and conversion of complete concentric to anteroposterior velum collapse (p=0.003).

Conclusions: Our data suggest that ESP may be limited as a rescue procedure after UAS non-response. ESP followed by UAS could be an effective staged approach for well-selected patients.