An anal fissure is no more than a tear or cut of the anal skin below the dentate line in the anal canal, usually very small. This injury can cause severe and disabling pain to the patient. Symptoms include rectal bleeding, pain, and burning after defecation that could last from minutes to hours.
Fissures are mainly caused by trauma to the anal canal, such as, with the passage of hard stool. Other theories, such as ischemia to the posterior midline of the anus, have been entertained. Fissures are usually located in the posterior midline of the anus, but can also be seen in the anterior midline, and in both locations at the same time. When a fissure is located off the midline of the anus, the clinician should investigate for other potentially complicated disease processes, such as, Crohn’s disease, trauma, tuberculosis, syphilis, HIV/AIDS or anal carcinoma. The diagnosis of the fissure is usually suggested by the description of the patient’s symptoms, and is easily confirmed by physical examination. Usually, other means of examination such as a digital rectal examination and anoscopy are not required and actually could be very painful for the patient.
The treatment of an anal fissure usually goes directed towards relieving the hypertony of the internal sphincter muscle that is associated with the condition. Fiber supplements, stool softeners and laxatives are also prescribed as needed. The treatment is also divided into medical or surgical. With the medical therapy, the aim is to chemically induce a relaxation of the internal sphincter muscle, while the aim of the surgical therapy is to mechanically cause that same effect.
The medications more widely used for the treatment of anal fissures are topical anti-inflammatory agents, such as, hydrocortisone. In addition, sphincter relaxants such as, nitrate formulations, oral and topical calcium channel blockers, adrenergic antagonists, topical muscarinic agonists, phosphodiesterase inhibitors and the use of botulinum toxin with success cure rates that range from 50 to 80% are implemented.
Historically, surgical techniques, have had a high success rate to treat this condition. Techniques such as, anal dilatation and posterior sphincterotomy, have been largely abandoned due to their side effects in particular, fecal incontinence. The American Society of Colon and Rectal Surgeon’s practice parameters for the management of anal fissures recommends, Lateral Internal Sphincterotomy as the surgical treatment of choice in medically refractory anal fissures, in which a small portion of the left aspect of the internal sphincter muscle is divided to achieve the desired mechanical relaxation needed to help the fissure heal.
Despite the mixed results with medical therapy, it is our practice to step up treatment options. From the use of topical anti-inflammatories to sphincter relaxants to surgical therapies, treatment options depend on the patient’s potential risk for fecal incontinence.