The treatment of anal fistulas with biologically derived products: is innovation better than conventional surgical treatment? An update.

New technical approaches involving biologically derived products have been applied in the treatment for anal fistulas in order to avoid the risk of fecal incontinence. The aim of this review was to evaluate the scientific evidence present in the literature regarding these techniques. Trials comparing surgery (fistulotomy, advancement mucosal flap closure and placement of seton) versus fibrin glue, fistula plug or acellular dermal matrix were considered. In fibrin glue versus traditional surgical treatment the healing rate was higher in the surgery group, and the recurrence rate was lower in the traditional surgery group, but these results were not statistically relevant. In acellular dermal matrix (ADM) versus traditional surgical treatment the recurrence rate of fistulas was significantly lower in the ADM group, but non-significant differences were recorded in incontinence and anal deformity. Our review shows that there are no significant advantages of the new techniques involving biologically derived products. Further randomized controlled trials are needed.