title: Body mass index predicts success in patients undergoing transoral robotic surgery for obstructive sleep apnea.
abstract: OBJECTIVE
  To determine the predictors of success in patients undergoing transoral robotic surgery (TORS) and multilevel procedures for the management of moderate-to-severe obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  METHODS
  A total of 121 patients (83 male, 38 female) underwent TORS between 2010 and 2013. All patients had robotic assisted lingual tonsillectomy, either as stand-alone surgery or in combination with palatal Z-plasty, lateral pharyngoplasty or uvulopalatopharyngoplasty. The apnea-hypopnea index (AHI) and body mass index (BMI) were measured preoperatively and 3 months postoperatively. Success was defined as AHI <20 and a decrease in AHI by 50%.
  
  
  RESULTS
  There was a significant difference in the preoperative and postoperative AHI in the entire cohort (42.7 vs. 22.2; p < 0.001). Overall, 84.3% of patients had an improvement in their AHI, 51.2% of patients met the criteria for success, and 14% met the criteria for cure defined as AHI <5. When stratifying by BMI, there was a significant difference in success when comparing patients with a BMI <30 versus those with a BMI >30 (69.4 vs. 41.7%; p = 0.004). The cure rate was 15.3% in patients with a BMI <30 and 11.1% in those with a BMI >30 (p = 0.54).
  
  
  CONCLUSIONS
  TORS lingual tonsillectomy and multilevel procedures were successful in treating moderate-to-severe OSAHS in selected patients. Preoperative BMI helps the clinician to predict success in these patients, with two thirds of patients having a clinically useful benefit.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, St. Joseph Mercy Health System, University of Michigan Health System, Ann Arbor, Mich., USA.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Hoff
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Glazer
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Spector
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010160:Palate, Soft / Q000601:surgery; D010614:Pharynx / Q000601:surgery; D011237:Predictive Value of Tests; D012307:Risk Factors; D065287:Robotic Surgical Procedures; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D014068:Tonsillectomy / Q000379:methods; D016896:Treatment Outcome; D014609:Uvula / Q000601:surgery