Subcutaneous lateral internal sphincterotomy (SLIS)--a safe technique for treatment of chronic anal fissure

Subcutaneous lateral internal sphincterotomy (SLIS) is an effective treatment for fissure in ano but carries a definite risk of incontinence. The aim of this study was to assess the efficacy and complications of SLIS in patients with chronic fissure in ano.

All patients presenting with a chronic anal fissure who underwent SLIS were entered into a prospective database. This is a review of these patients over 5 year's period (September 2002-2007). All operations were performed or directly supervised by a consultant colorectal surgeon. Short-term follow-up was at the first outpatient appointment (6 weeks postoperatively) and any impairment of continence was documented.

During the study period of 5 years, 96 patients underwent SLIS at our institution. Median patient age was 45 years (range 19-81). The median duration of symptoms was 65 days. No fissure failed to heal after SLIS. Minor complications were noted in five patients; 85% (82/96) attended the follow-up and out of these, 6% (5/82) reported early incontinence. One patient was incontinent to flatus, one to liquid and three to solid stool. After 12 weeks of follow-up, two patients were completely symptom free, one was incontinent to flatus and two were incontinent to liquid stool.

SLIS remains an effective treatment for chronic anal fissure. A small proportion of patients do suffer from faecal incontinence, which may be permanent in some cases. Careful patient selection and proper surgical training can reduce this risk.