Open lateral internal anal sphincterotomy under local anesthesia as the gold standard in the treatment of chronic anal fissures. A prospective clinical and manometric study.

BACKGROUND Chronic anal fissure is one of the most frequent proctological disorders in Western populations. Open lateral internal sphincterotomy is one of the therapeutic options accepted as the treatment of choice for chronic anal fissure, since it reduces the hypertonia of the internal anal sphincter (the main etiopathogenic mechanism of fissures), decreases anal pain, and allows the fissure to heal. MATERIAL AND METHODS We carried out a prospective study of 120 patients operated on for chronic anal fissure with open sphincterotomy under local anesthesia at our Proctology Outpatient Unit from 1998 to 2001. No preoperative studies, bowel preparation, or antibiotic prophylaxis were carried out. All patients were followed up after 1 week, 2 months, 6 months, and 1 year, and underwent an anal manometry before and after surgery. RESULTS Early complications: 3 hematoma-ecchymosis of the wound (2.5%), 3 self-limited hemorrhage events (2.5%). No hemorrhoidal thrombosis, fistulas, or perianal abscesses occurred. Fissures recurred in nine patients (7.5%) within one year. The initial rate of incontinence of 7.5% at two months dropped down to 5% at six months. The mean resting pressure (MRP) in incontinent patients was lower than in continent patients (55 +/- 7 mmHg versus 80.7 +/- 21 mmHg). The difference in mean squeeze pressure (MSP) between incontinent patients and continent patients was not statistically significant. CONCLUSIONS Open sphincterotomy under local anesthesia has a long-term rate of healing and a morbidity rate similar to other techniques. It may therefore be considered an effective treatment for chronic anal fissure.