Seton drainage prior to transanal advancement flap repair: useful or not?

INTRODUCTION: Transanal advancement flap repair (TAFR) provides a useful tool in the treatment of high transsphincteric fistulas. Recent studies indicate that TAFR fails in one out of three patients. Until now, no definite predictive factor for failure has been identified. Although some authors have reported that preoperative seton drainage might improve the outcome of TAFR, this could not be confirmed by others. We conducted the present study to assess the influence of preoperative seton drainage on the outcome of TAFR in a relatively large series. METHODS: Between December 1992 and June 2008, a consecutive series of 278 patients [M/F = 179:99, median age 46 years (range, 19–73 years)] with cryptoglandular, transsphincteric fistula, passing through the upper or middle third of the external anal sphincter underwent TAFR. Patients were recruited from the colorectal units of two university hospitals (Erasmus Medical Center, Rotterdam, n = 211; and Leiden University Medical Center, Leiden, n = 67). Baseline characteristics did not differ between the two clinics. Sixty-eight of these patients underwent preoperative seton drainage for at least 2 months and until the day of the flap repair. RESULTS: Median healing time was 2.2 months. In patients without preoperative seton drainage, the healing rate was 63%, whereas the healing rate was 67% in patients who underwent preoperative seton drainage. This difference was not statistically significant. No differences in healing rates were found between the series from Leiden and Rotterdam. CONCLUSION: Preoperative seton drainage does not improve the outcome of TAFR.