title: Microbiological analysis and endoanal ultrasonography for diagnosis of anal fistula in acute anorectal sepsis.
abstract: OBJECTIVE
  Treatment of anorectal sepsis requires prompt surgical drainage, but it is important to identify any associated anal fistula for preventing recurrence. We evaluated whether microbiological analysis and/or endoanal ultrasonography could be used to predict anal fistula in patients with acute anorectal sepsis.
  
  
  METHODS
  Five hundred fourteen consecutive patients with acute anorectal sepsis were studied. Clinical data, digital examination findings, endosonographic findings, and results of microbiological analysis were compared with definitive surgical findings of the presence or absence of anal fistula.
  
  
  RESULTS
  Anorectal abscess with anal fistula was found in 418 patients, and anorectal abscess without anal fistula was found in 96 patients. Microbiological examination showed that Escherichia coli, Bacteroides, Bacillus, and Klebsiella species were significantly more prevalent in patients with fistula (P<0.01), and coagulase-negative Staphylococci and Peptostreptococcus species were significantly more prevalent in patients without fistula (P<0.01). Results of endoanal ultrasonography were concordant with the definitive surgical diagnosis in 421 (94%) of 448 patients studied.
  
  
  CONCLUSIONS
  Acute anorectal sepsis due to colonization of "gut-derived" microorganisms rather than "skin-derived" organisms is more likely to be associated with anal fistula. When the microbiological analysis yields gut-derived bacteria, but no fistula has been found in the initial drainage operation, repeat examinations during a period of quiescence, including careful digital assessment and meticulous endosonography, are warranted to identify a potentially missed anal fistula.
authors.affiliation: Department of Surgery, Matsushima Hospital Colo-Proctology Center, Yokohama, Japan. toyozo7@yahoo.co.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Toyonaga
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsushima
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shimojima
authors.forename: Naomi
authors.initials: N
authors.lastname: Matsumura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kannyama
authors.forename: Makiko
authors.initials: M
authors.lastname: Nozawa
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Hatakeyama
authors.forename: Kazunori
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Yanagita
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000038:Abscess / Q000000981:diagnostic imaging / Q000382:microbiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012002:Rectal Diseases / Q000000981:diagnostic imaging / Q000382:microbiology*; D012003:Rectal Fistula / Q000000981:diagnostic imaging* / Q000382:microbiology* / Q000601:surgery; D014463:Ultrasonography