Efficacy and safety of botulinum toxin a injection compared with topical nitroglycerin ointment for the treatment of chronic anal fissure: A prospective randomized study

OBJECTIVES: To evaluate the efficacy and safety of botulinum toxin A injection compared with topical nitroglycerin ointment for the treatment of chronic anal fissure (CAF). METHODS: Fifty outpatients with CAF were randomized to receive either a single botulinum toxin injection (30 IU Botox((R))) or topical nitroglycerin ointment 0.2% b.i.d. for 2 wk. If the initial therapy failed, patients were assigned to the other treatment group for a further 2 wk. If CAF still showed no healing at wk 4, patients received combination therapy of botulinum toxin and nitroglycerin for 4 additional wk. Persisting CAF at wk 8 was treated according to the investigator's decision. Healing rates, symptoms, and side effects of the therapy were recorded at wk 2, 4, 8, 12, and 24 after randomization. RESULTS: The group initially treated with nitroglycerin showed a higher healing rate of CAF (13 of 25, 52%) as compared with the botulinum toxin group (6 of 25, 24%) after the first 2 wk of therapy (p < 0.05). At the end of wk 4, CAF healed in three additional patients, all receiving nitroglycerin after initial botulinum toxin injection. Mild side effects occurred in 13 of 50 (26%) patients, all except one were on nitroglycerin. CONCLUSIONS: Nitroglycerin ointment was superior to the more expensive and invasive botulinum toxin injection for initial healing of CAF, but was associated with more but mild side effects.