Long-term functional outcome and risk factors for recurrence after surgical treatment for low and high perianal fistulas of cryptoglandular origin

PURPOSE: This study assessed long-term functional outcome and explored risk factors for fistula recurrence in patients surgically treated for cryptoglandular fistulas. METHODS: Three hundred ten consecutive patients were surgically treated for perianal fistulas. After exclusion of patients with inflammatory bowel disease or HIV, 179 patients remained. Patients were divided into two groups: those who received fistulotomy for low perianal fistulas and those who received rectal advancement flap for high perianal fistulas. Time to fistula recurrence was the main outcome and Cox proportional hazard models were used to assess the importance of various risk factors. Functional outcome was assessed using the Vaizey and colorectal functional outcome (COREFO) questionnaires. RESULTS: The median follow-up duration was 76 months (range, 7-134). The 3-year recurrence rate for low perianal fistulas treated by fistulotomy (n=109) was 7 percent (95 percent confidence interval, 1-13 percent). In high transsphincteric fistulas treated by rectal advancement flap (n=70), the recurrence rate was 21 percent (95 percent confidence interval, 9-33 percent). In both groups, soiling was reported at 40 percent. None of the seven potential risk factors examined were statistically significant. CONCLUSIONS: Fistula recurrence rate after fistulotomy was low. No clear risk factors were found. Overall functional outcome in terms of continence was good. However, a substantial amount of patients reported soiling.