title: Analysis of upper airway obstruction by sleep videofluoroscopy in obstructive sleep apnea: a large population-based study.
abstract: OBJECTIVE
  To analyze the pattern of the upper airway obstruction in a large cohort of obstructive sleep apnea (OSA) patients using sleep videofluoroscopy (SVF).
  
  
  METHODS
  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.
authors.affiliation: Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Chul Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Sung-Lyong
authors.initials: SL
authors.lastname: Hong
authors.forename: Chae-Seo
authors.initials: CS
authors.lastname: Rhee
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Kim
authors.forename: Jeong-Whun
authors.initials: JW
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology*; D002648:Child; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020181:Sleep Apnea, Obstructive / Q000150:complications*; D014741:Video Recording; D055815:Young Adult