Drug Induced Sleep Endoscopy Versus Awake Endoscopy in Retrolingual Obstruction Assessment in Obstructive Sleep Apnea Patients: A Comparative Study.

ABSTRACT: The aim of this study is to evaluate the correlation of retrolingual obstruction determined by drug induced sleep endoscopy (DISE) and awake endoscopy evaluation of Muller maneuver (MM) and lingual tonsil hypertrophy (LTH) in patients with obstructive sleep apnea.A prospective cohort of 100 patients with obstructive sleep apnea who underwent DISE was assessed. The inclusion criteria were age between 18 and 70 years, and apnea-hypopnea index higher than 5. Friedman staging, LTH and MM were determined by awake endoscopy, as other physical findings. The authors evaluated the correlation of retrolingual obstruction determined by DISE using velum oropharynx tongue, epiglottis (VOTE) and nose, oropharynx, hypopharynx, larynx (NOHL) classification.When retrolingual MM was assessed, significant changes between awake and DISE were observed ( P = 0.000). Conversely, Friedman stage had no significant changes to DISE retrolingual findings ( P = 0.868). Analyzing LTH and DISE retrolingual findings according to NOHL and VOTE, if a cutoff value was established at 50%, DISE findings differ from awake: NOHL ( P <0.001) and VOTE ( P = 0.004). Nevertheless, if a restrictive cutoff at 75% was attached, DISE findings were similar to awake: NOHL ( P = 0.124) and VOTE ( P = 0.123).This study demonstrates that awake endoscopy determining LTH and Friedman stage is a mild predictor of collapse at retrolingual level, showing significant correlation to DISE only when severe retrolingual collapse is present. Our findings suggest that in-office awake endoscopy may have certain predictive value to select surgical patients.