Analysis of upper airway obstruction by sleep videofluoroscopy in obstructive sleep apnea: a large population-based study.
OBJECTIVES/HYPOTHESIS: To analyze the pattern of the upper airway obstruction in a large cohort of obstructive sleep apnea (OSA) patients using sleep videofluoroscopy (SVF).
STUDY DESIGN: Retrospective analysis.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.