title: Anal sphincter fibrillation: is this a new finding that identifies resistant chronic anal fissures that respond to botulinum toxin?
abstract: OBJECTIVE
  Anal fissures can be resistant to treatment and some patients may undergo several trials of medical therapy before definitive surgery. It would be useful to identify predictors of poor response to medical therapy. This study assesses the role of anorectal physiological criteria to identify patients with anal fissure predicted to fail botulinum toxin (BT) treatment.
  
  
  METHODS
  A retrospective analysis of anorectal physiological data collected for patients with resistant chronic anal fissures, referred to one consultant surgeon between 2007 and 2011, was undertaken. These were correlated with treatment plans and healing rates.
  
  
  RESULTS
  Twenty-five patients with idiopathic chronic anal fissures underwent anorectal physiology studies and were subsequently treated with BT injection. Eleven had a characteristic high-frequency low-amplitude 'saw tooth' waveform or anal sphincter fibrillation (ASF) and higher anal sphincter pressures. Nine (82%) of these patients had resolution of their anal fissure symptoms following treatment with BT. Of 14 patients with no evidence of ASF and a greater range of anal sphincter pressures, only one (7%) had resolution following BT.
  
  
  CONCLUSIONS
  ASF appears to be an anorectal physiological criterion that helps predict response of anal fissures to BT injection. This could help streamline fissure management.
authors.affiliation: Royal Victoria Infirmary, Newcastle upon Tyne, UK.
authors.forename: A
authors.initials: A
authors.lastname: Moon
authors.forename: P
authors.initials: P
authors.lastname: Chitsabesan
authors.forename: S
authors.initials: S
authors.lastname: Plusa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000503:physiopathology*; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage*; D002908:Chronic Disease; D005260:Female; D005401:Fissure in Ano / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage*; D012189:Retrospective Studies; D017211:Treatment Failure
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: Anal fissures; anal physiology; botulinum toxin