Combined Seton Placement, Infliximab Infusion, and Maintenance Immunosuppressives Improve Healing Rate in Fistulizing Anorectal Crohn's Disease

PURPOSE: Infliximab (anti-TNF alpha) has been used for the treatment of fistulizing Crohn's disease with variable efficacy. The aim of this study was to evaluate the efficacy of infliximab combined with selective seton drainage in the healing of fistulizing anorectal Crohn's disease. METHODS: This was a retrospective chart review of all patients with fistulizing Crohn's disease treated with infliximab between March 2000 and February 2002. RESULTS: Twenty-nine patients (12 male; mean age, 31 years) received a mean of 3 (range, 1-5) doses of infliximab 5 mg/kg. Twenty-one patients had perianal fistulas; eight had rectovaginal fistulas, four with combined rectovaginal/perianal fistula. Fourteen of 21 patients (67 percent) with perianal fistula had a complete response (mean follow-up, 9 months), 4 of the 14 relapsed (mean, 6 months), but all had a complete response to retreatment (mean, 9 months). A partial response occurred in four patients (19 percent), defined by decreased drainage (2 patients) or infliximab dependence (2 patients) requiring repeated dosing every six to eight weeks. Three patients (14 percent) had no response. Seton drainage was used before infusion in 13 perianal patients for perianal infection and 17 were treated with maintenance azathioprine or methotrexate. Of eight patients with rectovaginal fistula, complete response occurred in one, partial response in five, and no response in two. Two partial responders became infliximab dependent. A complete response was observed in one patient with isolated rectovaginal fistula, a partial response in five. No patient with a combined rectovaginal/perianal fistula had a complete response. Five rectovaginal fistula patients were taking maintenance immunosuppressive agents and two had seton drainage before infusion. CONCLUSIONS: Selective seton placement combined with infliximab infusion and maintenance immunosuppressives resulted in complete healing in 67 percent of Crohn's patients with perianal fistula and partial healing in 19 percent. Relapse was successfully treated with repeat infusion. Concomitant rectovaginal fistula was a poor prognostic indicator for successful infliximab therapy.