FOLLOW-UP-STUDIES OF SPHINCTER-PRESERVING OPERATIONS FOR ANAL FISTULAS

PURPOSE: This study was designed to evaluate and to compare the outcom e of anal fistula surgery using techniques involving minimal sphincter damage (sphincter-preserving) and conventional laying open techniques . PATIENTS AND METHODS: From January 1987 to December 1993, 2,242 pati ents with anal fistulas were treated surgically, of whom 1,070 had sph incter-preserving operations. These included 530 patients with low int ersphincteric fistulas (II L), 116 patients with high intersphincteric fistulas (II H), 73 patients with combined high and low intersphincte ric fistulas, 239 patients with transphincteric fistulas (III), and 11 2 patients with supralevator fistulas (IV). The open method of fistula surgery was used in 1,172 patients. RESULTS: Of 1,070 sphincter-prese rving operations, delayed healing occurred in 49 patients (4.6 percent ) and recurrent fistula occurred in 32 patients (3 percent). By using the open method in 1,172 patients, delayed healing occurred in 10 pati ents (0.9 percent) and recurrence of fistula occurred in 23 patients ( 2 percent). Failure rates increased with increasing depth and complexi ty of the fistula. CONCLUSION: Sphincter function is better with sphin cter-preserving fistula surgery than with the open method, although he aling was delayed more commonly in sphincter-preserving operations tha t with the open methods, and fistula recurrence was similar with the t wo methods. Choice of operation depends on depth of fistula, outcome b y manometry, and history of former operations.