Open coring-out (function-preserving) technique for low fistulas.

Abstract

Fistula operations can be very destructive to the anal sphincters; functional abnormalities occur easily after such surgery (even with an internal spincterotomy, minor incontinence occurs), hence, function-preserving operations are best. A low fistula goes through the thin sphincter muscle layer, making it more difficult to preserve than a deeper fistula. In 1984, we developed a technique to treat long string-type low fistulas showing heavy inflammation and induration from the internal opening to the primary focus, namely, the infected intersphincteric anal gland. This report shows the main surgical techniques used. TECHNICAL METHOD: For the fistula procedure, we developed an "open coring-out" technique in which the whole fistula is pulled out, making the inside and outside clearly visible. The portion from the internal opening to the primary focus is easily opened (fistulotomy), and the primary focus is excised by coring-out (fistulectomy). For the repair procedure, the sphincter muscle edges are fixed to the underlying tissues with two kinds of sutures. The cored portion is provided with adequate drainage and two sutures that narrow and prevent pocket formation. Since 1984, 319 of 5,055 patients with low fistulas have been treated using this technique, and 52 patients required postoperative treatment; delayed healing occurred in 48 patients; recurrence occurred in 4 patients. Of patients responding to our survey, 16 (6.4 percent) reported postoperative complaints. Delayed healing has always been a major problem. Because the repair procedure inhibits pocket formation and allows for adequate drainage of the cored portion, cases of delayed healing have been reduced to approximately 7 percent in the last four years. This technique, which is continually being improved and evaluated, is simple, has a low risk of infection, preserves functions, and prevents deformity of the anal verge and perineum.