Outcome of lateral internal sphincterotomy for anal fissure in a retrospective cohort of patients

Objective Chronic anal fissures (CAF) is a common cause of severe anorectal pain in adults causing poor quality of life. In case of failure of conservative treatments, lateral internal sphincterotomy (LIS) is an effective cure. We aimed to analyse the outcomes of LIS in a consecutive patients' series operated in a high volume Surgical Coloproctology Unit. Methods A retrospective cohort study was conducted on 422 patients with CAF undergoing surgical treatment between January 2015 and December 2019 at our Surgical Coloproctology Unit. Patients over the age of 18, not responding or recurring after a standard course of nifedipine ointment were included. Score of anal pain, bleeding, incontinence score, bowel habit was recorded before the operation and at 10th day and two months after treatment. After a mean follow-up of 48.7 months same data were recorded by a phone call on 362 patients available. Results Surgical treatment resulted in sharp and fast improvement of anal pain. Male patients, those complaining of constipation and those younger than 35 yr showed less improvement at short term. Postoperative complications included 3 cases of early postoperative bleeding, 3 abscesses at surgical wound and persisting postoperative bleeding in 28 cases (median 4 days). A mild, transient, faecal incontinence was reported at first post-operative visit in females compared to males and in patients older than 50 yrs. compared to younger (p < 0.001). At two months follow up visit 97.5% of patients reported absence of pain, normal continence and thus patients' satisfaction was very high. Nine patients (8 males) complained of persisting post-operative pain and had the fissure unhealed at two months follow up. At long term follow-up no patient complained of recurrent symptoms of anal fissure, continence was normal in all. Conclusions The surgical treatment of chronic anal fissure by means of lateral internal sphincterotomy gives excellent results with prompt resolution of anal pain. A standardized approach, surgeon's experience and high volume of cases may represent contributing factors for a good outcome, minimizing complications and recurrence. Normal bowel function contributes to improve and preserve results of surgical treatment.