Chronic anal fissure: new approaches to chemical sphincterotomy

An anal fissure is a split in the mucosa extending from the anal verge towards the dentate line. It currently affects 10% of patients attending proctology clinics. Recent studies have highlighted the role of increased internal anal sphincter pressure and decreased anodermal blood flow in the pathogenesis of chronic anal fissures. Acute fissures usually heal with conservative management. Fissures lasting greater than two months with features of chronicity, are unlikely to heal with conservative management. Lateral internal sphincterotomy has been the treatment of choice for chronic anal fissures. Because of the disability associated with surgery for healing anal fissure and the risk of incontinence, medical alternatives for surgery have been sought. Among different chemical agents, Glyceryl trinitrate (GTN) has been shown to be the first line treatment for chronic anal fissure but the transient sphincteric relaxation effect of pharmacologic agents such as GTN, makes them less effective than surgery. Although we have different forms of GTN products, they do not show a long acting effect on relaxing and enhancing the perfusion of anal sphincter, because they are soon metabolized. Most difficulties with current usage of drugs are due to poor compliance of patients. It can be taken into consideration that new formulation and novel combination of GTN with other treatments, in slow releasing forms may lead to acceptable strategies in the management of chronic anal fissure. As authors’ experience in this field, other clinical trials on the drug combination and slow releasing formulations are warranted to generate new data on the subject.