RESUMO
Internal anal sphincterotomy for treating chronic anal fissure can irreversibly damage anal continence. Reversible chemical sphincterotomy may be achieved by topical application of nitric oxide donors [isosorbide dinitrate]. This study was undertaken to compare local application of isosorbide dinitrate with lateral internal sphincterotomy. A sample of 153 patients with chronic anal fissure was allocated to treatment with sphincterotomy [69 patients] or local isosorbide dinitrate tablets [84 patients]. Patients were followed-up for one year. Common age group was 30-40 years. The healing rate was 97% in surgical group and 47.8% in medical group. The recurrence after healing in last group was 44.4%. The cost of treatment by sphincterotomy under local anesthesia is nearly equal to treatment by topical application of isosorbide dinitrate tablet. Lateral internal sphincterotomy under local anesthesia is considered the operation of choice in surgically fit patients in treatment of chronic anal fissure. Topical application of isosorbide dinitrate can be used for those who are surgically unfit or refuse operation