Treatment of high anal fistulae by primary occlusion of the internal ostium, drainage of the intersphincteric space, and mucosal advancement flap.

In a prospective study on 224 patients with so-called high-fistula in ano (189 transsphincteric, 35 suprasphincteric) the long-term results of a sphincter-saving operation technique were assessed. The follow-up period was 1 to 7.5 years. This technique consists of one-stage fistulectomy as well as of drainage of the intersphincteric space by internal sphincterotomy. The site of the former primary orifice of the fistula is adapted by multiple peranally performed single stitches, including mucosal advancement flap distal to the original fistulous opening. Postoperatively, 24 cases of suture leakage occurred (9% with the transsphincteric and 20% with the suprasphincteric fistula). 27 patients developed late complications like fistula recurrences or combinations of fistula and anal abscess (10.7% with the transsphincteric and 19.9% with the suprasphincteric fistula). Anal manometry was carried out preoperatively as well as postoperatively. A significant decrease in the postoperative resting pressure compared to the preoperative value was determined. The two fistula groups differed statistically both with regard to the resting pressure and the contraction pressure. Significant impairment of continence developed in 21% of patients with transsphincteric fistula but in 43% of patients with suprasphincteric fistula (intermittent fecal spoiling/use of perineal pads). The total percentage of complications rose with the number of previous fistula operations.