Long-term results of seton drainage on complex anal fistulae in patients with Crohn's disease

Background. The aim of this study was to assess the long-term (greater than 2 years) results of seton drainage on anal fistulae in patients with Crohn's disease. Methods. Between September 1990 and September 1999, 32 patients with Crohn's disease underwent seton drainage for complex anal fistulae. The median follow-up time in these patients was 62 months (range, 25-133 months). In 10 patients (31.3%), recurrent perineal abscesses occurred with inlying seton drainage, and these were drained by re-insertion of the seton. A Malecot catheter was also inserted in 8 patients with recurrence. Results. The overall success rate of long-term seton usage was 87.5%. The subsequent associated procedure was simple seton removal (n = 9), secondary core-out fistulectomy (n = 7), or lay-open fistulotomy (n = 4). Eleven patients still had the seton in place. Recurrence developed in 3 patients (33%) who underwent simple seton removal and in 2 patients (18.2%) who underwent the secondary core-out procedure or fistulotomy. At the last follow-up examination, continence had not changed in 28 (87.5%) of the 32 patients. No change in continence was experienced by 10 of the 11 patients who underwent secondary fistulotomy or the secondary core-out procedure. Conclusions. Long-term seton drainage for complex anal fistula in Crohn's disease is efficacious in both treating sepsis and preserving anal sphincter function. A relatively good result was achieved by the secondary core-out procedure or fistulotomy at the time of seton removal.