title: Obesity in general elective surgery.
abstract: BACKGROUND
  Obese patients are generally believed to be at a higher risk for surgery than those who are not obese, although convincing data are lacking.
  
  
  METHODS
  We prospectively investigated a cohort of 6336 patients undergoing general elective surgery at our institution to assess whether obesity affects the outcome of surgery. Exclusion criteria were emergency, vascular, thoracic, and bariatric operations; transplantation procedures; patients under immunosuppression; and operations done under local anaesthesia. Postoperative morbidity was analysed for non-obese and obese patients (body-mass index <30 kg/m(2) vs >or=30 kg/m(2)). Obesity was further stratified into mild obesity (30.0-34.9 kg/m(2)) and severe obesity (>or=35 kg/m(2)). Risk factors were analysed with univariate and multivariate models.
  
  
  RESULTS
  The cohort consisted of 6336 patients, of whom 808 (13%) were obese, 569 (9%) were mildly obese, and 239 (4%) had severe obesity. The morbidity rates in patients who were obese compared with those who were not were much the same (122 [15.1%] of 808 vs 901 [16.3%] of 5528; p=0.26), with the exception of an increased incidence of wound infections after open surgery in patients who were obese (17 [4%] of 431 vs 92 [3%] of 3555, p=0.03). Incidence of complications did not differ between patients who were mildly obese (91 [16.0%] of 569), severely obese (36 [15.1%] of 239), and non-obese (901 [16.3%] of 5528; p=0.19). In multivariate regression analyses, obesity was not a risk factor for development of postoperative complications. Of note, the additional medical resource use as estimated by a new classification of complications showed no differences between patients who were and were not obese.
  
  
  CONCLUSIONS
  Obesity alone is not a risk factor for postoperative complications. The regressive attitude towards general surgery in obese patients is no longer justified.
authors.affiliation: Department of Visceral Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Dindo
authors.forename: Markus K
authors.initials: MK
authors.lastname: Muller
authors.forename: Markus
authors.initials: M
authors.lastname: Weber
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Clavien
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000601:surgery; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000209:etiology