Transanal advancement flap repair of transsphincteric fistulas

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

Between January 1992 and January 1997, 44 consecutive patients with a transsphincteric perianal fistula passing through the middle or upper third of the external anal sphincter underwent transanal advancement flap repair. There were 34 male patients, and the median age was 44 (range, 19-72) years. Twenty-four patients (55 percent) had previously undergone one or more prior attempts at repair. With the patient in prone jackknife position, the internal opening of the fistula was exposed using a Parks retractor. The crypt-bearing tissue around the internal opening and the overlying anoderm was excised. A layer of mucosa, submucosa, and internal sphincter fibers was mobilized 4 to 6 cm proximally. The base of the flap was approximately twice the width of its apex. The flap was advanced and sutured to the anoderm below the level of the internal opening. The median follow-up was 12 months. Fecal continence was evaluated in 43 patients by means of a questionnaire.

Transanal advancement flap repair was successful in 33 patients (75 percent). Success was inversely correlated with the number of prior attempts. In patients with no or only one previous attempt at repair the healing rate was 87 percent. In patients with two or more previous repairs the healing rate dropped to 50 percent. In 15 patients (35 percent) continence deteriorated after transanal advancement flap repair. Twenty-six patients (59 percent) had a completely normal continence preoperatively. Ten of these patients (38 percent) encountered soiling and incontinence for gas after the procedure, whereas three subjects (12 percent) complained of accidental bowel movements. Eighteen patients (41 percent) had continence disturbances at the time of admission to our hospital. In two of these patients (11 percent), incontinence deteriorated.

The results of transanal advancement flap repair in patients with no or only one previous attempt at repair are good. In patients who have undergone two or more previous attempts at repair the outcome is less favorable. Remarkably, the number of previous attempts did not adversely affect continence status.