Palatine Tonsil Size Predicts Upper Airway Obstruction in Adults with Obstructive Sleep Apnea

Abstract

Background and Objectives: Drug-induced sleep endoscopy (DISE) is widely used to diagnose obstructive sleep apnea syndrome (OSAS). Palatine tonsil hypertrophy is a frequently encountered potential source of upper airway obstruction. Here, we determined whether the pre-surgery size of the palatine tonsil could be used to predict the extent and pattern of upper airway obstruction during DISE of adults with OSA. Materials and Methods: We retrospectively evaluated 268 patients (mean age 42.80±12.34 years, range 17-73 years) who underwent polysomnography and were diagnosed with OSAS in a single medical center from 2013 to 2020. The Brodsky tonsil scores of all subjects were obtained via physical examination. DISE proceeded with each patient supine. The extent of obstruction was evaluated by dividing the upper airway into retropalatal and retrolingual levels (the Koo's DISE classification system). Data were analyzed via simple linear regression. A p<0.05 was considered statistically significant. Results: We found relationships between the Brodsky tonsil score and the extents of obstruction at the retropalatal level. A significantly negative relationship between the score and retropalatal anteroposterior collapse was apparent (slope coefficient -0.115, p<0.05), as well as a significantly positive relationship between the score and retropalatal lateral collapse (slope coefficient 0.274, p<0.05). However, at the retrolingual level, no significant relationship was apparent between the Brodsky score and the extent of obstruction (p>0.05). Conclusion: In adult patients with OSA, as the palatine tonsil size increased, lateral pharyngeal wall obstruction at the retropalatal level became more severe, and the pattern of upper airway collapse at that level tended to be lateral rather than anteroposterior or concentric.