Fine-tuning of the extent of lateral internal sphincterotomy: spasm-controlled vs. up to the fissure apex.

PURPOSE: This study was designed to compare the results of controlled lateral internal sphincterotomy by using anal calibrators with those of sphincterotomy up to the fissure apex in a randomized, prospective fashion.

METHODS: In the fissure apex group, sphincterotomy was extended to the level of the fissure apex, and in the spasm-controlled group, serial small sphincterotomies and anal caliber measurements followed until an anal caliber of 30 mm was obtained.

RESULTS: The preoperative anal caliber was 24 +/- 1.9 (range, 20-28) mm and 24.9 +/- 2.44 (range, 19-28) mm in the spasm-controlled and fissure apex groups, respectively (P = 0.127). Postoperatively, the spasm-controlled group had a mean anal caliber of 31.5 +/- 1.28 (range, 30-32) mm, and the fissure apex group had 32.5 +/- 2.33 (range, 25-37) mm (P = 0.035). In the fissure apex group, a significant negative correlation was determined between the postoperative anal caliber and time of relief of pain (r = -0.568, P = 0.001). The early (7 and 28 days) postoperative anal incontinence scores were significantly higher in the fissure apex group (P = 0.002, P < 0.0001, respectively). A significant positive correlation between the anal caliber measurements and anal incontinence scores at 28 days and 2 months also was noted in the fissure apex group (r = 0.406, P = 0.023; and r = 0.364, P = 0.044).

CONCLUSIONS: Controlled sphincterotomy provided a faster relief of pain, and it was associated with a lower rate of early postoperative disturbance of continence and an insignificantly lower rate of treatment failure compared with sphincterotomy up to the fissure apex.