Abstract
PURPOSE: This study aimed to assess the impact of positional changes on upper airway obstruction patterns during drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea (OSA) and identify the airway regions most responsive to this change. Special focus was placed on the tongue base, a critical area in OSA pathophysiology. METHODS: This prospective study was conducted from June 2021 to June 2024. DISE was performed in patients with obstructive sleep apnea (OSA) in supine and lateral positions to simulate the effect of positional therapy. Findings were evaluated using the VOTE classification. RESULTS: The examination was performed on 186 patients, with a median Apnea-Hypopnea Index (AHI) of 19.3. In the supine position, complete obstructions were noted at the soft palate (88.2%), oropharynx (33.3%), tongue base (53.2%), and epiglottis (15.6%). Lateral positioning significantly reduced obstructions, particularly at the tongue base, where obstruction resolved in 94/99 of cases (94.9%). This improvement was significantly more pronounced at the tongue base than at other sites (p < 0.001). CONCLUSION: These results suggest that DISE can identify airway regions responsive to positional changes, potentially guiding clinical decisions on positional therapy. The findings show a significant reduction in tongue base obstruction during lateral positioning in DISE. Since tongue base obstruction is a key contributor to airway collapse in OSA, this improvement suggests a practical, non-invasive treatment approach. While these findings highlight an acute association between lateral positioning and reduced obstruction, further studies are needed to evaluate its long-term clinical efficacy.