title: Incidence of fistulas after drainage of acute anorectal abscesses.
abstract: OBJECTIVE
  The aim of this study was to assess the incidence of anal fistulas and factors related to this incidence after incision and drainage of acute cryptoglandular anorectal abscesses.
  
  
  METHODS
  Of 170 patients without previous anal fistulas, 146 were followed up for an average of 99 (range, 22-187) months after abscess drainage or until a fistula appeared.
  
  
  RESULTS
  Fifty-four (37 percent) patients developed a fistula, and 15 (10 percent) patients developed a recurrent abscess. The incidence of fistulas was higher in females than in males (50 vs. 31 percent; P = 0.0403), especially regarding anterior abscesses (88 vs. 33 percent). Abscesses growing Escherichia coli were more prone to fistula formation than those growing other bacteria (46 vs. 27 percent; P = 0.0368).
  
  
  CONCLUSIONS
  Incision and drainage alone of acute anorectal abscesses is recommended, because an unnecessary primary fistulotomy can be avoided in more than half of the patients by this approach. For superficial anterior abscesses in females, however, primary fistulotomy may be considered.
authors.affiliation: Fourth Department of Surgery, Helsinki University Central Hospital, Finland.
authors.forename: K P
authors.initials: KP
authors.lastname: Hämäläinen
authors.forename: A P
authors.initials: AP
authors.lastname: Sainio
mesh_terms: D000038:Abscess / Q000601:surgery*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D004322:Drainage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012002:Rectal Diseases / Q000601:surgery*; D012003:Rectal Fistula / Q000209:etiology*; D012008:Recurrence