Long-term Outcome of Perianal Fistulizing Crohn's Disease Treated With Infliximab

Abstract

Little is known about the long-term efficacy of infliximab for patients with fistulizing perianal Crohn's disease. We evaluated outcomes and predictors of outcomes in these patients. The medical records of 156 patients treated with infliximab for fistulizing perianal Crohn's disease at 2 referral centers from 1999 through 2010 were reviewed through September 2011. Cumulative probabilities of fistula closure and recurrence were estimated by using the Kaplan-Meier method. Predictors of outcomes were identified by using a Cox proportional hazards model. When infliximab treatment began, only 17.9% of patients had a simple fistula; seton drainage was performed for 97 patients (62%). Concomitant immunosuppressants were given to 90 patients (56%). After a median follow-up period of 250 weeks, 108 patients (69%) had at least 1 fistula closure. Cumulative probabilities of first fistula closure were 40% and 65% at 1 and 5 years, respectively. Factors that predicted fistula closure were ileocolonic disease (hazard ratio [HR] = 1.88), concomitant immunosuppressants (HR = 2.58), duration of seton drainage <34 weeks (HR = 2.31), and long duration of infliximab treatment (HR = 1.76). Of the 108 patients with fistula closure, cumulative probabilities of first fistula recurrence were 16.6% and 40.1% at 1 and 5 years, respectively. Forty-four patients (28.9%) developed an abscess during follow-up. A number of infliximab infusions greater than 19 was associated with less abscess recurrence (HR = 0.33). At the maximal follow-up time, 55% of patients had fistula closure. About two-thirds of patients with fistulizing perianal Crohn's disease had fistula closure, and one-third had fistula recurrence after infliximab initiation. Combination therapy, duration of seton drainage less than 34 weeks, and long-term treatment with infliximab were associated with better outcomes.