Carapeti EA, Kamm MA, McDonald PJ, et al. Randomised controlled trial shows that glyceryl trinitrate heals anal fissures, higher doses are not more effective, and there is a high recurrence rate. Exclusion criteria were fissures caused by Crohn disease or HIV, receipt of nitrate treatment for ischaemic heart disease, history of migraine, or pregnancy. The ointment was applied manually to the skin of the anal verge 3 times daily for 8 weeks.
Main outcome measures Healing rate, pain, headache, and fissure recurrence.
A injections were more effective than glyceryl trinitrate for complete healing of anal fissure . Commentary The 2 studies by Carapeti and colleagues and Brisinda and colleagues provide useful information to guide treatment of chronic anal fissure. However, GTN may have unpleasant side effects, particularly headache. Therefore, we need to know the minimum dose necessary to heal a fissure and the shortest effective duration of treatment. Local injection of botulinum toxin has emerged as another rapid and effective treatment option.