title: Treatment of perianal fistula in Crohn's disease: a systematic review and meta-analysis comparing seton drainage and anti-tumour necrosis factor treatment.
abstract: OBJECTIVE
  The introduction of anti-tumour necrosis factor (anti-TNF; infliximab and adalimumab) has changed the management of Crohn's perianal fistula from almost exclusively surgical treatment to one with a much larger emphasis on medical therapy. The aim of this systematic review was to provide an overview of the success rates of setons and anti-TNF for Crohn's perianal fistula.
  
  
  METHODS
  Studies evaluating the effect of setons and anti-TNF on Crohn's perianal fistula were included. Studies assessing perianal fistula in children, rectovaginal and rectourinary fistulae were excluded. The primary end-point was the fistula closure rate. Partial closure and recurrence rates were secondary end-points.
  
  
  RESULTS
  Ten studies on seton drainage were included (n = 305). Complete closure varied from 13.6% to 100% and recurrence from 0% to 83.3%. In 34 anti-TNF studies (n = 1449), complete closure varied from 16.7% and 93% (partial closure 8.0-91.2%) and recurrence from 8.0% to 40.9%. Four randomized controlled trials (n = 1028) comparing anti-TNF with placebo showed no significant difference in complete or partial closure in meta-analysis (risk difference 0.12, 95% CI -0.06 to 0.30 and 0.09, 95% CI -0.23 to 0.41, respectively). Subgroup analysis (n = 241) showed a significant advantage for complete fistula closure with anti-TNF in two trials with follow-up > 4 weeks (46% vs 13%, P = 0.003 and 30% vs 13%, P = 0.03). Of four included cohort studies, two revealed a significant difference in response in favour of combined treatment (P = 0.001 and P = 0.014).
  
  
  CONCLUSIONS
  Closure and recurrence rates after seton drainage as well as anti-TNF vary widely. Despite a large number of studies, no conclusions can be drawn regarding the preferred strategy. However, combination therapy with (temporary) seton drainage, immunomodulators and anti-TNF may be beneficial in achieving perianal fistula closure.
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.|Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: de Groof
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Sahami
authors.affiliation: Department of Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Lucas
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: C Y
authors.initials: CY
authors.lastname: Ponsioen
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: W A
authors.initials: WA
authors.lastname: Bemelman
authors.affiliation: Department of Surgery, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: C J
authors.initials: CJ
authors.lastname: Buskens
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D000328:Adult; D015331:Cohort Studies; D003424:Crohn Disease / Q000150:complications*; D004322:Drainage / Q000379:methods*; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use; D008297:Male; D010502:Perineum / Q000601:surgery; D016032:Randomized Controlled Trials as Topic; D012003:Rectal Fistula / Q000209:etiology / Q000628:therapy*; D012008:Recurrence; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D005765:Gastrointestinal Agents; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab
keywords: Crohn's perianal fistula; anti-TNF; seton