Correlation of site of obstruction between two dynamic evaluation modalities in obstructive sleep apnea patients: drug-induced sleep endoscopy and sleep videofluoroscopy.

PURPOSE: Drug-induced sleep endoscopy (DISE) and sleep videofluoroscopy (SVF) are two dynamic modalities for evaluating the upper airway in patients with obstructive sleep apnea (OSA). We evaluated the correlation of obstructive sites determined by DISE and SVF in OSA patients and elucidate findings that can improve the accuracy of upper airway assessment.

METHODS: A consecutive series of 63 patients with OSA who underwent DISE and SVF were the subjects of this study. The DISE and SVF findings were divided according to the anatomical structure responsible for the collapse, including the soft palate (SP), oropharyngeal lateral walls (LW), tongue base (TB), and larynx (LX). The obstruction was graded on the three-point scale: 0, no obstruction; 1, partial obstruction; or 2, complete obstruction. Additionally, grade 1.5 TB obstruction was designated when the posterior displacement of the anterior tongue was detected during simultaneous retropalatal obstruction. The agreement rate and Cohen's kappa test between the two modalities were also assessed.

RESULTS: The agreement rate between the two modalities was highest in LX (88.9%) followed by SP (85.7%), TB (76.1%), and LW (74.6%) (Cohen's kappa value = 0.757 in LX, 0.642 in SP, 0.637 in TB, 0.612 in LW, respectively). When grade 1.5 and 2 TB obstructions were combined, the agreement rate increased to 88.9% (Cohen's kappa value = 0.757).

CONCLUSIONS: We found a good overall agreement between the two dynamic airway evaluation modalities during drug-induced sleep, and this correlation may be improved if the posterior displacement of the anterior tongue during DISE is used as a sign of TB obstruction.