Anal Fissure

Number of patients are presented to the surgical clinics daily complaining pain in defecation without bleeding from anus. Most of the times it would be an anal fissure but could be another pathology as well. This article discussed about the anal fissures.
An anal fissure is an ulceration of the epithelium of the anal canal that result in severe burning pain during defecation, it may associated with mild bleeding as well.

Aetiology

Two main factors contribute to the formation of anal fissures. Hard stools/constipation is the first contributing factor which causes local trauma to the anal mucosa. Second, affected is the tight anal sphincters. Tight /hypertonic anal sphincters enhances the traumatic effect of the hard faeces and reduces the blood supply to the anal mucosa. This tightness is mainly due to reduced or lack of production of a substance called “Nitric oxide/NO” which involved in sphincter relaxation.

Whatever the cause once the initial tear occurs, a vicious cycle starts; non-healing and repeated trauma leads to development of chronic deep fissures. But even without tight anal sphincters some people develop anal fissures.

Classification

Anal fissures are classified mainly according to their duration. Anal fissures are considered to be acute if they are superficial, have well-demarcated edges and presented within 6 weeks from the onset. They are considered chronic if they have been present for more than 6 weeks and have whitish edges, if there is a characteristic skin  tag and if the fibres of the internal anal sphincter are visible in the base of the fissure.

Addition to this classification, according to the position of the fissure – Anterior, Posterior or Unusual position. Posterior ones are the most common.

There is another classification as primary or secondary fissures. Here, the fissures occur according to the above discussed mechanism is called primary anal fissure. Secondary anal fissures are associated with other diseases such as chronic inflammatory bowel disease (Ulcerative colitis, Crohn’s), HIV, tuberculosis, syphilis and cancers. Secondary fissures are usually multiple or located in unusual positions.

Superficial fissures involve only the superficial layers of the anal canal, and base of the fissure does not reach anal sphincters. The vast majority of superficial fissures will heal spontaneously within days or within a few weeks of appropriate conservative treatment.

Deep anal fissures are recognized by deep, wide ulcers; in the base of the ulcer fibres of the anal sphincters can be seen. Deep fissures often persist and either tend not to heal without intervention or recur regularly.

Symptoms and diagnosis

As mentioned earlier pain is the predominant symptom with or without the presence of fresh bleeding. The pain develops during defecation and is described as a sharp pain, like ‘a knife cutting’. It may last lasts for several minutes or the entire day.

Management

The treatment modality ranges from conservative management to surgical management. Basic goals of management are treating the contributing factors and the factors that aggravate the condition.
Management of abnormal defecation patterns includes dietary advice- increase water intake ( 2.5- 3 liters/day), high fibre diet, and medication (stool softeners and topical analgesics). Here you would be given local anesthetic creams that reduces pain during defecation. And sometimes oral pain killers as well. Even though all these treatments are nonspecific; these alone result in healing anal fissures in almost 50% of cases.


When those measure fails, specific medical treatments can be started to relax the tightened sphincter and increase the blood supply to sphincter.

  1. Glyceryl trinitrate (GTN) and diltiazem are the widely using two local agents that help to relax the internal anal sphincter. GTN acts as nitric oxide donor. Usually it should be used at least for 2 months and has shown effectiveness of 68%. The major issue with GTN is it causes headache in 25% of the patients.
  2. Diltiazem belong to the drug category called calcium channel blocker, which causes vasodilatation and increases blood flow to smooth muscles and relaxes muscle tone.
  3. Botulinum toxin injection to the sphicters acts by blocking the release of the acetylcholine neurotransmitter; when injected correctly it will relaxes the sphincter for about 2-3 moths.


Surgical treatments for chronic fissures includes mainly the lateral sphincterotomy that involves the division of the internal anal sphincter to restore a normal anal sphincter tone from the initial hypertonia. It can be performed either as an open or closed procedure. Healing rates are around of 85%. Compared to all other treatments for anal fissure, lateral sphincterotomy produces the highest healing rates but also a significant risk of incontinence.

There are few other surgical management options like fissurectomy and anal cutaneous advancement flaps with or without fissurectomy depending on anal sphincter tone and the severity of the disease which are not usually practice in Sri Lanka.

If you develop symptoms of anal fissure; in Sri Lankan setup you should consult a general surgeon or a gastrointestinal surgeon. Now in most of the hospital there are “Rectal Clinics” specially designed for treat anor-eactal conditions.

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