The ideal lateral internal sphincterotomy: clinical and endosonographic evaluation following open and closed internal...

To evaluate the relationship between extent of internal sphincter division following open and closed sphincterotomy, as assessed by anal endosonography, with fissure persistence/recurrence and faecal incontinence.

A total of 140 consecutive patients undergoing lateral internal sphincterotomy (LIS) for idiopathic chronic anal fissure were prospectively studied. Preoperative clinical assessment was performed together with a postoperative clinical and endosonographic examination. Three zones of the internal sphincter, identifiable by endosonography, were used to describe the uppermost extent of LIS. Primary end-points were fissure persistence/recurrence and faecal incontinence.

A total of 140 patients, median age 49.5 years (IQR: 38-56 years) were included. Seventy-five (53.6%) and 65(46.4%) patients underwent percutaneous LIS (PLIS) and open LIS (OLIS) respectively. Median follow-up was 21 months (IQR: 14-29 months). Persistence and recurrence rates were 2.9% (4/140) and 5.7% (8/140) respectively. 7.9% (11/140) patients scored > 3 on the Jorge and Wexner Faecal Incontinence scale. PLIS was associated with a trend towards higher fissure persistence/recurrence rates than OLIS (12.0%vs 4.6%, P = 0.141). OLIS was significantly associated with a higher proportion of complete sphincterotomies (CS) than PLIS (56/65 vs 48/75, P = 0.003). A CS was associated with a lower fissure persistence or recurrence rate (1/104 vs 11/36, P < 0.001) but higher incontinence scores (11/104 vs 0/36 cases with Wexner scores > 3, P = 0.042) than following incomplete sphincterotomy. There was a strongly significant increase in incontinence scores (P < 0.001) and decrease in recurrence rates (P < 0.001) with increasing length of sphincterotomy.

We recommend a short and CS using either PLIS or OLIS for the treatment of idiopathic anal fissure.