OPEN CORING-OUT (FUNCTION-PRESERVING) TECHNIQUE FOR LOW FISTULAS

PURPOSE: Fistula operations can be very destructive to the anal sphinc ters; functional abnormalities occur easily after such surgery (even w ith an internal spincterotomy, minor incontinence occurs), hence, func tion-preserving operations are best. A low fistula goes through the th in sphincter muscle layer, making it more difficult to preserve than a deeper fistula. In 1984, we developed a technique to treat long strin g-type low fistulas showing heavy inflammation and induration from the internal opening to the primary focus, namely, the infected intersphi ncteric anal gland. This report shows the main surgical techniques use d. TECHNICAL METHOD: For the fistula procedure, we developed an ''open coring-out'' technique in which the whole fistula is pulled out, maki ng the inside and outside clearly visible. The portion from the intern al opening to the primary focus is easily opened (fistulotomy), and th e primary focus is excised by coring-out (fistulectomy). For the repai r procedure, the sphincter muscle edges are fixed to the underlying ti ssues with two kinds of sutures. The cored portion is provided with ad equate drainage and two sutures that narrow and prevent pocket formati on. RESULTS: Since 1984, 319 of 5,055 patients with low fistulas have been treated using this technique, and 52 patients required postoperat ive treatment; delayed healing occurred in 48 patients; recurrence occ urred in 4 patients. Of patients responding to our survey, 16 (6.4 per cent) reported postoperative complaints. Delayed healing has always be en a major problem. Because the repair procedure inhibits pocket forma tion and allows for adequate drainage of the cored portion, cases of d elayed healing have been reduced to approximately 7 percent in the las t four years. CONCLUSION: This technique, which is continually being i mproved and evaluated, is simple, has a low risk of infection, preserv es functions, and prevents deformity of the anal verge and perineum.