Insights gained from the management of problematical anal fistulae at St. Mark's Hospital, 1984-88.

Twenty-four (3.6 percent) patients with problematical anal fistulae out of 671 with anal fistulae were analysed to assess the reasons for their recurrences and ultimate outcome. Thirteen patients (group A) had recurrent fistulae despite two definitive attempts at surgery at this hospital (median number of previous procedures before referral to this hospital was two, range 0-7; median number of definitive procedures at this hospital was three, range 3-4). In five of these patients, the reason for recurrence was missed primary (four cases) or secondary tracks (one case) at earlier operations. Five patients required multiple operations related to the use of setons. Eleven other patients (group B) required colostomy construction, eight because of severe perianal sepsis, two because of complex fistulae, and one for postrectal dermoid. Fistula healing occurred ultimately in all patients in group A after a median of 14 months (range 4-38 months). In group B, fistula healing occurred in eight patients after a median of 7.5 months (range 2-55 months) after colostomy construction. Only one patient has had a proctectomy, and five still have their colostomy. Of the other 18 patients, continence is normal in 14, there is mucus leakage in two, flatus incontinence in one and faecal incontinence in one. In conclusion, persistent attempts to resolve anal fistulae in difficult cases are frequently successful in the long term and result in good continence.