title: Computer-assisted quantitative upper airway analysis following modified uvulopalatal flap and lateral pharyngoplasty for obstructive sleep apnoea: a prospective case-controlled study.
abstract: OBJECTIVE
  The study aims to perform static and dynamic quantitative assessment of the anatomical changes of the upper airway before and after modified uvulopalatal flap and lateral pharyngoplasty and comparison of the improvement in airway dimensions, collapsibility and extent of normalisation to that of control patients.
  
  
  METHODS
  Prospective case-controlled study.
  
  
  METHODS
  Computer-assisted quantitative measurement is used to compare upper airway parameters before and after modified uvulopalatal flap and lateral pharyngoplasty in patients with obstructive sleep apnoea (OSA).
  
  
  METHODS
  Patients with obstructive sleep apnoea diagnosed on sleep study and failed positive airway pressure therapy.
  
  
  METHODS
  Sleep study results, upper airway parameters and symptom score following surgery and its comparison to normal patients to assess the degree and extent of normalisation.
  
  
  RESULTS
  Thirty-five study and 32 control subjects were recruited and completed the study. All the retropalatal airway dimensions like area, transverse diameter, longitudinal diameter and collapsibility showed statistically significant improvement following surgery. The success rate of this surgery is 43% (15 of 35) overall, 58% (14 of 24) for patients with isolated palatal obstruction and only 9% (1 of 11) for patients with multi-level obstruction. Comparing obstructive sleep apnoea to the control subjects, there are obvious and logical differences in their biostatistics, sleep study parameters and airway dimensions. The postoperative obstructive sleep apnoea retropalatal longitudinal diameter has a higher tendency of normalising to be comparable to those of control patients.
  
  
  CONCLUSIONS
  Modified uvulopalatal flap and lateral pharyngoplasty is an effective surgical technique for the treatment of obstructive sleep apnoea. The surgery increases the resting retropalatal dimensions and reduces the retropalatal collapsibility.
authors.affiliation: Department of Otolaryngology, Changi General Hospital, 2 Simei Street 3, Singapore.
authors.forename: P P
authors.initials: PP
authors.lastname: Hsu
authors.forename: A K L
authors.initials: AK
authors.lastname: Tan
authors.forename: E C
authors.initials: EC
authors.lastname: Gan
authors.forename: Y H
authors.initials: YH
authors.lastname: Chan
authors.forename: M M
authors.initials: MM
authors.lastname: Goh
authors.forename: P K S
authors.initials: PK
authors.lastname: Lu
authors.forename: W L
authors.initials: WL
authors.lastname: Howe
mesh_terms: D016022:Case-Control Studies; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010160:Palate, Soft / Q000601:surgery*; D010614:Pharynx / Q000601:surgery*; D017286:Polysomnography; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000601:surgery*; D013524:Surgical Flaps; D014068:Tonsillectomy; D016896:Treatment Outcome; D014609:Uvula / Q000601:surgery*; D014743:Videotape Recording