Long-term outcome after surgery for Crohn's anal fistula.

Aim: Treatment of Crohn's anal fistula remains challenging and little is known about factors associated with healing. The aim of this study was to assess the rate of healing after surgical treatment and analyse clinical variables related to healing.

Method: A total of 119 patients [63 women, mean age 36 (±13.7) years] with histopathologically verified Crohn's disease underwent a surgical procedure for anal fistula at four main referral centres in Sweden, January 1998 to December 2009. Baseline and treatment-related variables were recorded and analysed for correlation with fistula healing at a final follow-up after a mean of 7.2 (median 7.1, 1.0-17.5) years.

Results: Of the 119 patients 62 (52%) were healed at final follow-up. Fourteen healed after one procedure and the remaining 48 healed after a further median of 4.0 (2-20) procedures. Ten (8%) patients were subjected to a proctectomy. Final healing was more common in patients operated with a procedure aiming at eradicating the fistula (P = 0.0001), without proctitis (P = 0.02) and a shorter duration of Crohn's disease (P = 0.0019).

Conclusion: Long-term healing of a Crohn's anal fistula can be expected in about half of the patients, usually after repeated surgical treatment. The probability for cure was higher when a curative operation was performed in a patient without proctitis and with a shorter duration of Crohn's disease. An attempt to close a Crohn's anal fistula is thus often worthwhile.