Anocutaneous advancement flap repair of transsphincteric fistulas

The purpose of this study was to evaluate the healing rate of transsphincteric perianal fistulas after anocutaneous advancement flap repair and to examine the impact of this procedure on fecal continence.

Between January 1997 and June 1999, 26 consecutive patients with a transsphincteric perianal fistula passing through the middle or upper third of the external anal sphincter underwent anocutaneous advancement flap repair. There were six female patients, and the median age was 39 (range, 27-54) years. Twenty patients (77 percent) had previously undergone one or more prior attempts at repair. With the patient in the prone-jackknife position, the internal opening of the fistula was exposed using a Lone Star Retractor System, and the crypt-bearing tissue around the internal opening as well as the overlying anoderm was excised. An (inverted) U-shaped flap, including perianal skin and fat, was created. The base of the flap was approximately twice the width of its apex. The flap was advanced and sutured to the mucosa and underlying internal anal sphincter proximal to the closed internal opening. The median follow-up time was 25 months. Fecal continence was evaluated in 23 patients by means of a questionnaire.

Anocutaneous advancement flap repair was successful in 12 patients (46 percent). Success was inversely correlated with the number of prior attempts. In patients who had undergone no or only one previous attempt at repair (n = 9), the healing rate was 78 percent. In patients with two or more previous repairs (n = 17) the healing rate was only 29 percent. In seven patients (30 percent) continence deteriorated after anocutaneous advancement flap repair. Eleven patients (48 percent) had a completely normal continence preoperatively. Two of these patients (18 percent) encountered soiling and incontinence for gas after the procedure, whereas two subjects (18 percent) complained of accidental bowel movements. Twelve patients (52 percent) presented with continence disturbances at the time of admission to our hospital. In this group, deterioration was observed in two patients (17 percent).

The results of anocutaneous advancement flap repair in patients with no or only one previous attempt at repair are moderate. In patients who have undergone two or more previous attempts at repair the outcome is poor. Based on the relatively low healing rate and deterioration of continence, this procedure seems less suitable for high transsphincteric fistulas than transanal mucosal advancement flap repair.