title: Obesity is a negative predictor of success after surgery for complex anal fistula.
abstract: BACKGROUND
  It was the aim of this study to compare the outcome of surgery for complex anal fistulas in obese and non-obese patients.
  
  
  METHODS
  All patients with complex anorectal fistulas who underwent fistulectomy and/or rectal advancement flap repair were prospectively recorded. Surgery was performed in a standardized technique. Body mass index (BMI [kg/m2]) was used as objective measure to indicate morbid obesity. Patients with a BMI greater than 30 were defined as obese, and patients with a BMI below 30 were defined as non-obese. The parameters analyzed related to BMI included success or failure, and reoperation rate due to recurrent abscess. Success was defined as closure of both internal and external openings, absence of drainage without further intervention, and absence of abscess formation.
  
  
  RESULTS
  Within two years, 220 patients underwent advancement flap repair and met the inclusion criteria. 55% of patients were females, mean age was 39 (range 18-76) years, and the majority of fistulas were located at the posterior site. 69% of patients (152/220) were non-obese (BMI < 30), whereas 31% (68/220) were obese (BMI > 30). After a median follow-up of 6 months, primary healing rate ("success") for the whole collective was 82% (180/220). Success was significantly different between non-obese and obese patients: In non-obese patients, recurrence rate was significantly lower than in obese patients (14% vs. 28%; p < 0.01). Moreover, reoperation rate due to recurrent abscess with the need for seton drainage in the failure groups was significantly higher in obese patients when compared to non-obese patients (73% vs. 52%; p < 0.01). Using multivariate analysis, obesity was identified as independent predictive factor of success or failure (p < 0.02).
  
  
  CONCLUSIONS
  Obese patients are at higher risk for failure after surgery for complex anal fistula.
authors: Department of Proctology, Krankenhaus Barmherzige Brueder Regensburg, Regensburg, Germany. oliver.schwandner@barmherzige-regensburg.de
authors: O
authors: O
authors: Schwandner
references: Dis Colon Rectum. 2007 Apr;50(4):459-63
references: 17195081
references: Dis Colon Rectum. 2008 Oct;51(10):1475-81
references: 18626715
references: Br Med J. 1961 Feb 18;1(5224):463-9
references: 13732880
references: Dis Colon Rectum. 2003 May;46(5):584-9
references: 12792432
references: Dis Colon Rectum. 2004 Apr;47(4):432-6
references: 14978618
references: Dis Colon Rectum. 2005 Jul;48(7):1337-42
references: 15933794
references: Dis Colon Rectum. 2002 Dec;45(12):1616-21
references: 12473884
references: Tech Coloproctol. 2005 Jul;9(2):166-8
references: 16007352
references: Int J Colorectal Dis. 2008 Jul;23(7):697-701
references: 18322659
references: Int J Colorectal Dis. 2008 Mar;23(3):319-24
references: 18038233
references: Colorectal Dis. 2008 Jun;10(5):420-30
references: 18479308
references: Tech Coloproctol. 2005 Jul;9(2):89-94
references: 16007368
references: Dis Colon Rectum. 2008 Jun;51(6):852-7
references: 18317841
references: Br J Surg. 2006 Oct;93(10):1202-7
references: 16952209
references: Dis Colon Rectum. 2005 Jun;48(6):1228-32
references: 15868234
references: Am J Surg. 2006 Jul;192(1):34-40
references: 16769272
references: Dis Colon Rectum. 2007 Oct;50(10):1508-11
references: 17701070
references: Nat Rev Gastroenterol Hepatol. 2010 Aug;7(8):419-20
references: 20683488
references: Dis Colon Rectum. 1999 Nov;42(11):1419-22; discussion 1422-3
references: 10566529