Open vs. closed sphincterotomy for chronic anal fissure

PURPOSE: This study was undertaken to compare the healing rate and long-term effects on continence of open and closed lateral internal sphincterotomy. METHODS: Charts of 864 patients with chronic anal fissure who underwent internal sphincterotomy as a single procedure over five years by a group of 12 colorectal surgeons were reviewed. Open internal sphincterotomy (OIS) was performed in 521 patients, whereas 343 had closed internal sphincterotomy (CIS). There was no difference in sex or age between the groups. A questionnaire inquiring about clinical outcome, changes in continence, and degree of satisfaction with the procedure was mailed to all patients. A total of 549 (63.5 percent) patients, 324 (62.2 percent) with OIS and 225 (65.6 percent) with CIS, returned their questionnaires. Average follow-up was three (range, 1-6) years. RESULTS: Differences in persistence of symptoms (3.4 OIS vs. 5.3 percent CIS), recurrence of the fissure (10.9 vs. 11.7 percent CIS), and need for reoperation (3.4 percent OIS vs. 4 percent CIS) were statistically not significant. However, statistically significant differences were seen in the percentage of patients with permanent postoperative difficulty controlling gas (30.3 vs. 23.6 percent; P 0.062), soiling underclothing (26.7 vs. 16.1 percent; P < 0.001), and accidental bowel movements (11.8 vs. 3.1 percent; P < 0.001) between those who underwent OIS and those who had CIS. Although 90 percent of patients reported general overall satisfaction, more patients undergoing CIS (64.4 percent) than OIS (49.7 percent) were very satisfied with the results of the procedure. CONCLUSIONS: Lateral internal sphincterotomy is highly effective in treatment of chronic anal fissure but is associated with significant permanent alterations in continence. CIS is preferable to OIS because it effects a similar rate of cure with less impairment of control.