Clinical and manometric results of endorectal advancement flaps for complex anal fistula

Endorectal advancement flap repair is a well-recognized method for the treatment of complex anorectal fistula. The purpose of this study was to prospectively assess the clinical and functional results of endorectal advancement flaps for complex anorectal fistula and to identify factors that affect outcome.

A prospective study of 56 patients was performed. Clinical and functional results were studied using the Wexner continence scale and anal manometry before and after surgery. Factors associated with recurrence and incontinence were analyzed by univariate and multivariate regression analysis.

Sixty endorectal flaps were constructed in 56 patients. Mean age was 49 years (range 24-74). The fistula was of cryptoglandular origin in 91.1% cases. Mean follow-up was 43.8 months. The technique was repeated in four patients because of recurrence (7.1%), with subsequent healing in all cases. There were significant reductions in maximum resting pressure 3 months after surgery (83.6+/-33.2 vs 45.6+/-18.3, p<0.001) and maximum squeeze pressure (208.8+/-91.5 vs 169.5+/-75, p<0.001). Before surgery, five patients (8.9%) reported incontinence symptoms. After surgery, 78.6% patients had normal continence, seven patients (12.5%) complained of minor incontinence, and five (9%) had major continence disturbances. None of the variables studied (age, sex, previous fistula surgery, rectovaginal fistula, and Crohn's disease) affected the outcome of the procedure in multivariate analysis.

Endorectal advancement flap repair is an effective technique for complex anal fistula, with a low recurrence rate (7.1%). Patients (21.4%) reported disturbed anal continence. It is still not possible to identify factors that are predictive of failure or incontinence.