Ligation of intersphincteric fistula tract versus mucosal advancement flap in patients with high transsphincteric fistula-in-ano: a prospective randomized trial.

PURPOSE

The aim of this study was to compare the ligation of the intersphincteric fistula track with the mucosal advancement flap in the treatment of high transsphincteric anal fistulas.

DESIGN AND SETTING

This was a prospective randomized study performed at academic medical centers.

PATIENTS

Patients with transsphincteric anal fistulas involving the upper part of anal sphincter were included.

INTERVENTION

Patients were randomly assigned to either ligation of intersphincteric fistula track or mucosal advancement flap.

MAIN OUTCOME MEASURES

The primary end points of the study were fistula closure, recurrence within 1 year, and continence by using the Wexner score. Secondary end points were morbidity, postoperative pain with the use of the visual analog scale, and quality of life with the use of the Cleveland Global Quality of Life score.

RESULTS

There were 70 patients (35 in each group). Mean age was 36.1 years in patients undergoing ligation of the intersphincteric fistula track vs 32.9 years in patients undergoing mucosal advancement flap (p = 0.33). Mean visual analog scale after 1 week was significantly higher in the mucosal advancement flap group than in the ligation of intersphincteric fistula track group (3.1 vs 4.8, p = 0.04), but no significant difference was found after 4 weeks. Primary healing was achieved in 33 patients undergoing ligation of the intersphincteric fistula track vs 32 patients undergoing mucosal advancement flap (p = 0.99). Mean healing time was 22.6 days in the ligation of intersphincteric fistula track group vs 32.1 days in mucosal advancement flap group (p = 0.01). After 1 year of follow-up, successful outcome was achieved in 26 patients (74.3%) undergoing ligation of intersphincteric fistula track and in 20 patients (65.7%) undergoing mucosal advancement flap (p = 0.58). No significant change in Wexner score occurred 4 weeks postoperatively. There was no significant difference between groups regarding Cleveland Global Quality of Life score (p = 0.5 and 0.07 after 4 and 12 weeks).

LIMITATIONS

The short-term follow-up is a probable limitation. Although the sample size was calculated to detect difference with 80% power at a significance level of 5%, the negative result within this relatively small number of patients might have resulted from type II statistical error.

CONCLUSIONS

In patients with high transsphincteric anal fistulas, both ligation of intersphincteric fistula track procedure and mucosal advancement flap have a similar long-term healing rate, recurrences, continence, and quality of life. However, ligation of the intersphincteric fistula track has the advantage of less postoperative pain.