High transphincteric perianal fistula represents a technical challenge for surgical management. We compared the effects of partial rectal wall advancement flap versus the mucosal advancement flap in the treatment of high transphincteric perianal fistula in a randomized study in patients with anal fistula.

Consecutive patients treated for transphincteric anal fistula at our institution were evaluated for inclusion. Participants were randomly allocated to receive Group I: Fistulectomy, closure of internal sphincter and rectal advancement flap includes mucosa, submucosa, and circular muscle layer sutured 1 cm below the level of internal opening or Group II: The same as group one but the flap includes only mucosa and submucosa. Study variables included fistula closure rate, continence, morbidity, postoperative pain, hospital stay and quality of life.

Forty patients with high transphincteric perianal fistula were randomized and completed the study. Operative time was 31.6 ± 6.8 min in group I, and 29.4 ± 4.7 min in group II (P = 0.783). Hospital stay was significantly more in group 2 (96.35 ± 9.5 vs. 105.8 ± 13.23) (P = 0.014) Immediate postoperative complications, occurred in one patients (5%) exposed to disruption in group I and 6 patients (30%) in group II. Recurrence occurred in 2 patients (10%) in the group I and 8 patients (40%) in group II. Two patients (10%) in group I developed incontinence for flatus and no patients in the group II develop such complication.

Partial thickness advancement flap is better than mucosal advancement flap.