Analysis of upper airway obstruction by sleep videofluoroscopy in obstructive sleep apnea: a large population-based...

To analyze the pattern of the upper airway obstruction in a large cohort of obstructive sleep apnea (OSA) patients using sleep videofluoroscopy (SVF).

Retrospective analysis.

This study included 922 OSA patients who underwent both polysomnography and SVF. Their mean age, apnea-hypopnea index, and body mass index were 46.8 years, 34.2 per hour, and 26.2 kg/m2, respectively. Sleep was induced by intravenous injection of midazolam, and the obstruction pattern was determined on SVF when oxygen saturation dropped by more than 4% in pulse oxymetry.

The anatomic structure and airway level, which were most commonly involved in obstruction, were the soft palate (77.9%) and the oropharynx (88.1%), respectively. The soft palate alone was the most common obstructed structure in mild OSA (43.2%), and the combination of the soft palate and the tongue base was more frequent in severe OSA (45.2%). The tongue base or the hypopharynx was progressively more involved in moderate/severe OSA cases (P<.001, respectively), and a multiplicity of obstruction pattern also increased according to OSA severity (P<.001). However, 32.4% of the patients with mild OSA also had multiple obstructive anatomic structures.

Even if multiplicity of obstruction pattern was most commonly associated with severe OSA, almost one third of mild OSA patients also showed multiple anatomic structures and levels of obstruction. Therefore, a precise evaluation for multiplicity of obstruction patterns should precede the decision of a treatment plan, regardless of disease severity.