INTRODUCTION

Infliximab is a monoclonal antibody against tumor necrosis factor-alpha, which has been shown to be effective in fistulating Crohn's disease. The safety of infliximab in patients with potential perianal sepsis is uncertain. This study was designed to assess the safety and outcome of infliximab therapy combined with surgery for patients with fistulating anal Crohn's disease.

METHODS

All patients receiving infliximab for fistulating anal Crohn's disease between 2000 and 2004 were studied. Patients' demographics, clinical findings, magnetic resonance imaging, and examination under anesthesia were recorded. Perianal Crohn's disease activity index before and 8 to 12 weeks after three infusions of infliximab (5 mg/kg) were recorded. Routine policy was to insert drainage seton sutures at the time of preinfliximab examination under anesthesia and then remove it after the second infusion. Complications of treatment and outcome at the last clinic follow-up were recorded.

RESULTS

Twenty-two patients underwent infliximab treatment (6 males; median age, 35 (range, 16-60) years). Twenty-one patients had preinfliximab examination under anesthesia: 12 required abscess drainage; 17 had at least one drainage seton suture inserted. Fourteen patients underwent pretreatment magnetic resonance imaging to identify clinically occult collections. All but one patient were established on immunomodulator therapy before infliximab treatment. Perianal Crohn's disease activity index improved significantly after infliximab infusion (preinfusion: median, 11, range, 8-17; postinfusion: median, 8, range, 5-16; P<0.001). There were no serious complications of infliximab treatment. At median follow-up of 21 (range, 4-31) months, only four patients achieved sustained fistula healing. Five patients have required defunctioning or proctectomy. Four patients have required repeated infusions of infliximab.

CONCLUSIONS

Infliximab therapy in combination with examination under anesthesia/seton drainage is a safe and effective short-term treatment for fistulating anal Crohn's disease. Long-term fistula healing rates are low.