Hypoxic burden reduction after lateral pharyngoplasty in patients with obstructive sleep apnea: Beyond the apnea-hypopnea index

Abstract

The apnea-hypopnea index (AHI), traditionally used to assess obstructive sleep apnea (OSA) severity and surgical outcomes, has limitations in reflecting cardiovascular risk and pathophysiological burden. Although lateral pharyngoplasty has demonstrated favorable outcomes regarding AHI reduction, its impact on hypoxic burden (HB) remains unknown. This study evaluated HB changes after lateral pharyngoplasty in patients with OSA, including those classified as surgical failures according to Sher’s criteria. This observational, longitudinal study with a mixed retrospective and prospective design included 27 adults with OSA who underwent lateral pharyngoplasty (version 6) between 2016 and 2025, with complete preoperative and postoperative polysomnographic data for HB assessment. HB was calculated using validated commercial software. Nonparametric tests were used for intra- and intergroup comparisons. Surgical success was defined according to Sher’s criteria. A significant reduction in HB was observed across all variants: total sleep time (median from 97.1%·min/h to 35.0%·min/h, p < 0.0001), REM sleep, NREM sleep, and supine and non-supine positions, with a significant reduction in median AHI (median from 33.8 to 12.3 events/h, p < 0.0001). Even among surgical failures according to Sher’s criteria, HB decreased significantly (median from 102.5%·min/h to 67.3%·min/h, p = 0.0107), suggesting pathophysiological improvement not captured by AHI alone. HB is a potentially more sensitive metric to assess therapeutic response in OSA, incorporating multiple dimensions of nocturnal hypoxemia beyond AHI. Lateral pharyngoplasty promoted consistent HB reduction, including in surgical failures, supporting HB as a complementary tool for therapeutic evaluation, with potential applications in cardiovascular risk stratification.