부산대학교 도서관

With a better understanding of anal fissure pathophysiology since the 1990's, a number of papers have been published regarding the treatment of anal fissure using sphincter relaxants. Pharmacological effects on the internal anal sphincter (smooth muscle) have been well known. Nitric oxide is the principal nonadrenergic, noncholinergic neurotransmitter in the smooth muscle, and its release results in internal anal sphincter relaxation. Internal anal sphincter tone is regulated by increased cytosolic calcium levels and calcium-channel blockers reduce internal anal sphincter tone. Nitroglycerin ointment and other organic nitrate preparations acting as nitric oxide donors lead to decreased resting anal pressure and healing rates of 62-92 percent. However, one drawback of nitric oxide donors is severe headaches. Topical application of calcium channel blockers may be as effective as topical nitrates without the risk of headaches. Locally injected botulinum toxin, which prevents neural transmission by preventing acetylcholine release from presynaptic nerve terminals, showed healing rates of 53-96 percent with a risk of temporary incontinence. There is no evidence of the superiority of the pharmacological treatment compared to lateral internal sphincterotomy.