Primary closure of fistulectomy wound with island advancement flap in management of low peri-anal fistula: a new technique for rapid healing

ABSTRACT

Low perianal fistula can be treated by fistulotomy but this may involve prolonged wound healing and compromise anal continence. On the other hand, if fistulectomy is done, gapping of the wound occurs with further increase in the raw surface. Primary closure of the fistulectomy wound with island advancement composite flap to induce rapid healing and compare its clinical and anal manometric outcome with that of fistulotomy. This study was done on 49 patients with low perianal fistulas. All patients were subjected to anal manometric study preoperatively and 6 weeks and 3 months postoperatively including measurement of resting anal pressure [RAP], maximal squeeze anal pressure [MSP] and functional sphincteric length [FSL] of anal canal. The type of fistula was assessed and the radial distance of the external opening from the anal verge was measured. Patients were divided into 2 groups. FF group included 26 patients in whom fistulectomy with careful dissection of fistula tract from the external sphincter and primary closure of the raw surface with island advancement flap were done. F group included 23 patients in whom fistulotomy alone was done. Follow up was done for a mean period of 9.1 months to assess continence, healing and anal manometric parameters. In the FF group, intersphincteric fistula was found in 57.7% and trans-sphincteric fistula in 42.3%. The mean radial distance of external openings was 4.1cm. In the F group, intersphincteric fistula was found in 56.5% and trans-sphincteric fistula in 43.5%. The mean radial distance of the external openings was 4.2cm. In the FF group, all flaps were viable and healed primarily and the extra-anal stitches were removed by the end of the 3[rd] week. Two patients were incontinent to flatus [7.7%] and regained full continence by the end of follow up. No recurrence was recorded. In the F group, complete wound healing occurred after a mean period of 9.8 weeks, incontinence to flatus occurred in one patient and to both flatus and fluid stool in another 2 patients [13%]. Two of them regained full continence by the end of follow up but one still incontinent to flatus. Recurrence occurred in 2 patients [8.3%]. Anal manometric study showed insignificant change in the post-operative RAP and FSL in both groups as well as the MSP in the FF group. The MSP showed significant drop at 3 months in F group. On conclusion, fistulectomy with careful dissection of the fistula tract from the external anal sphincter and primary closure of the raw surface with island advancement flap resulted in more rapid healing with less deformity of the anus and preserve anal pressure and continence with no recurrence