Comparison of level and degree of upper airway obstruction by Muller's maneuver and drug-induced sleep endoscopy in obstructive sleep apnea patients

Objective: This study aimed to compare and analyze the level and degree of observed upper airway obstruction in patients with obstructive sleep apnea (OSA) using Muller's maneuver (MM) and drug-induced sleep endoscopy (DISE). We sought to find a method for evaluating the upper airway that could be used to determine surgical sites. Methods: This study included 80 OSA patients who visited Kyung Hee Medical Center and underwent polysomnography (PSG) from March 2013 to March 2014. Obstructive levels observed by MM were classified into retropalatal level, or the lateral wall and retroglossal level. These levels were compared with those determined by DISE through the VOTE classification. Results: Based on the results of MM and DISE, lateral wall and retropalatal level obstructions showed relatively high conformity, while retroglossal level obstruction exhibited considerable differences. When evaluated at each level, patients with obstruction on MM also showed partial or complete obstruction on DISE at same level, and patients with no obstruction on DISE also showed no obstruction on MM at same level. Conclusion: Both examination methods revealed the same obstruction levels in all cases except epiglottic level, but there were some differences in obstructive degree. MM is capable of detecting obstruction levels in the upper airway and can be used to determine surgical sites in cases when DISE cannot be used due to a patient's condition or a clinic's circumstances. (C) 2016 Elsevier Ireland Ltd. All rights reserved.