Open vs. closed lateral internal sphincterotomy for idiopathic fissure-in-ano: A prospective, randomized, controlled trial

PURPOSE: Internal sphincterotomy remains the "gold standard" for treatment of anal fissure but is associated with a risk of imperfect continence. Recent studies have suggested that surgical technique (open vs. closed) may influence incontinence rates after sphincterotomy. This study was designed to assess the short-term and long-term incidence of incontinence after open and closed internal sphincterotomy. METHODS: Seventy-nine patients were randomly assigned to open or closed internal sphincterotomy, performed in standardized fashion by trainee staff. Standardized questionnaires assessing continence (modified Wexner score) were administered preoperatively and at 1, 6, and 52 weeks. Postoperative stay, pain scores, complications, and fissure healing were prospectively assessed by an independent observer. RESULTS: Three patients were lost to followup, leaving 36 closed (16 males; mean age, 45.1 years) and 40 open (21 males; mean age, 47.9 years) internal sphincterotomy patients for assessment. All operations were performed as day case procedures with no readmissions. At six weeks postoperative, 96 percent of fissures had healed. There were no significant differences in pain scores between closed and open internal sphincterotomy at Day 1 or Day 3 postoperative. New incontinence of any grade was seen in 6.8 percent of patients at 52-week follow-up. Three patients (4.1 percent, 1 closed, 2 open) suffered major incontinence at 52 weeks. There were no significant differences in continence at 1, 6, or 52 weeks, although more open patients experienced minor imperfections at 1 week. CONCLUSIONS: Incontinence after internal sphincterotomy is not insignificant. The technique (closed vs. open) does not seem to influence incontinence rates.