Randomised trial of topical 0.2% glyceryl trinitrate and lateral internal sphincterotomy for the treatment of patients with chronic anal fissure: long-term follow-up.

OBJECTIVE: To compare outcomes 24 months after treatment of chronic anal fissure with 0.2% glyceryl trinitrate ointment (GTN) or lateral internal sphincterotomy. DESIGN: Prospective, randomised trial. SETTING: One teaching, one private, and 3 district hospitals, U.K. SUBJECTS: Seventy patients were randomised into two groups of 35 each to use 0.2% GTN ointment or have a lateral internal sphincterotomy. MAIN OUTCOME MEASURES: Resolution of symptoms and healing of fissures assessed after 24 months. RESULTS: All those operated on were initially cured but one fissure recurred after 8 months. Nineteen of 35 fissures treated with GTN healed. The remaining 16 patients randomised to use GTN ointment whose fissures did not heal were then treated by sphincterotomy. Three patients whose fissures healed successfully with GTN developed recurrences within 6 months of completing treatment. The remaining 16 of 19 patients treated with GTN whose fissures healed were free of symptoms with no clinical evidence of recurrence after 24 months follow-up. CONCLUSIONS: Many anal fissures heal with topical treatment with GTN. Lateral internal sphincterotomy remains effective but should be reserved for patients who fail to respond to initial chemical sphincterotomy.