Identifying the best therapy for chronic anal fissure

Abstract

Chronic anal fissure (CAF) is a painful tear or crack which occurs in the anoderm. The optimal algorithm of therapy for CAF is still debated. Lateral internal sphincterotomy (LIS) is a surgical treatment, considered as the 'gold standard' therapy for CAF. It relieves CAF symptoms with a high rate of healing. Chemical sphincterotomy (CS) with nitrates, calcium blockers or botulinum toxin (BTX) is safe, with the rapid relief of pain, mild side-effects and no risk of surgery or anesthesia, but is a statistically less effective therapy for CAF than LIS. This article considers if aggressive treatment should only be offered to patients who fail pharmacological sphincterotomy. Aspects of anal fissure etiology, epidemiology and pathophysiology are considered with their meaning for further management of CAF. A molecular model of chemical interdependence significant for the chemistry of CAF healing is examined. Its application may influence the development of optimal therapy for CAF. BTX is currently considered the most effective type of CS and discussion in this article scrutinizes this method specifically. Although the effectiveness of BTX vs. LIS has been discussed, the essential focus of the article concerns identifying the best therapy application for anal fissure. Elements are presented which may help us to predict CAF healing. They provide rationale for the expansion of the CAF therapy algorithm. Ethical and economic factors are also considered in brief. As long as the patient is willing to accept the potential risk of fecal incontinence, we have grounds for the 'gold standard' (LIS) as the first-line treatment for CAF. The author concludes that, when the diagnosis of the anal fissure is established, CS should be considered for both ethical and economic reasons. He is convinced that a greater understanding and recognition of benign anal disorders by the GP and a proactive involvement at the point of initial diagnosis would facilitate the consideration of CS at an earlier, more practical stage with improved outcomes for the patient.

A prospective, randomized, double-blind study comparing the efficacy of diltiazem, glyceryl trinitrate, and lidocaine for the treatment of anal fissure in children

“…Previous studies have reported that anal resting pressure is a primary reason the AF does not self-heal because anal hypertonia results in low perfusion and ischemia of the overlying anoderm [13]. Figure 2 shows a relationship between anal pressure and anal blood flow.…”

“…Microtrauma of the anoderm and AF causes anal pain that aggravates IAS spasms causing high anal pressure which contributes to decreased anal perfusion. It is generally believed that decreased anal pressure is associated with an improvement in anodermal perfusion by the vascular endothelium after trauma, which leads to smooth muscle contraction [6,13]. Figure 2 shows a relationship between anal pressure and anal blood flow.…”

“…Furthermore, previous studies have shown that anal hypertonia is secondary to spasm created by defecation [13,17,18]. Microtrauma of the anoderm and AF causes anal pain that aggravates IAS spasms causing high anal pressure which contributes to decreased anal perfusion.…”

“…However, the role of impaired blood flow in the pathogenesis of AF is unclear. Although most reports exist in the literature the presence of an increased tone of the internal anal sphincter (IAS) represents the most reliable cause of fissuring and symptoms [1][2][3][4][5][6][7][8][9][12][13][14][15].…”

Anal fissure

“…2,12 Headaches also occur in a similar proportion of patients using topical calcium channel blockers, however they occur less frequently so may be more tolerable. 3 Patients using topical glyceryl trinitrate should not take sildenafil, tadalafil or vardenafil due to the risk of hypotension. For patients with angina or heart failure taking nitrates, topical glyceryl trinitrate may cause nitrate tolerance if used during the nitratefree interval.…”