Randomized clinical trial comparing botulinum toxin injections with 0·2 per cent nitroglycerin ointment for chronic anal fissure

Abstract

Abstract Background In recent years treatment of chronic anal fissure has shifted from surgical to medical. This study compared the ability of two non-surgical treatments—botulinum toxin injections and nitroglycerin ointment—to induce healing in patients with idiopathic anal fissure. Methods One hundred adults were assigned randomly to receive treatment with either type A botulinum toxin (30 units Botox® or 90 units Dysport®) injected into the internal anal sphincter or 0·2 per cent nitroglycerin ointment applied three times daily for 8 weeks. Results After 2 months, the fissures were healed in 46 (92 per cent) of 50 patients in the botulinum toxin group and in 35 (70 per cent) of 50 in the nitroglycerin group (P = 0·009). Three patients in the botulinum toxin group and 17 in the nitroglycerin group reported adverse effects (P < 0·001). Those treated with botulinum toxin had mild incontinence to flatus that lasted 3 weeks after treatment but disappeared spontaneously, whereas nitroglycerin treatment was associated with transient, moderate-to-severe headaches. Nineteen patients who did not have a response to the assigned treatment crossed over to the other therapy. Conclusion Although treatment with either topical nitroglycerin or botulinum toxin is effective as an alternative to surgery for patients with chronic anal fissure, botulinum toxin is the more effective option.