A perianal fistula is a communication that occurs between the rectum or anal canal and perianal skin, typically in the vicinity of the anus. The perianal fistula is a high incidence disease, occurs more in men than in women and is often initially diagnosed between 30 and 50 years.
Origin and types of fistulas
This communication is called fistulous, it has its origin in an internal fistulous opening, within the year, and ends on the external fistulous opening in the perianal skin. Based on the theory cryptoglandular, most fistulas originate from a blockage of glands inside the anal canal, whose function is to lubricate to allow egress of stool. More rarely, fistulas are related to trauma, anal fissures, Crohn's disease or previous surgery in the anal region.
On his way from inside the anus to the skin, this fistulous tract through the anal sphincter, responsible for the proper continence of stool. Fistulas are classified depending on the area where the fistulous tract through the anal sphincter.
Usually, the first symptom of a perianal fistula is the appearance of a perianal abscess. This is a pocket of pus under the skin near the anus. This abscess usually requires surgical drainage as initial treatment. Subsequently, between 25% and 50% of patients will develop fistula established. In this case, the most common symptoms are:continuous or intermittent discharge, sometimes stain underwear patient; pain in the area where the external fistulous opening is, especially before and perianal suppuration moisture if maintained over time causes itching and burning in the area of the fistula days.
Differences between fistula and haemorrhoids
The typical feature of the fistula is suppuration, showing yellowish-white material. Pain may not be related to deposition and may be relieved when the discharge occurs.
Instead, hemorrhoids can cause bleeding, the patient may feel the output of a "package" after the effort deposition or feel more intense pain in case of hemorrhoidal thrombosis.
If we have a perianal fistula, the only definitive treatment in Coloproctology is surgery. As we have said before, if the diagnosis is made by the appearance of a perianal abscess, the treatment is surgical drainage. This operation, although apparently simple, it is important to do it correctly as this will determine a shorter fistulous tract and prevent the occurrence of fistulas with several paths.
Once the fistula is already established, it is important to know the relationship between the fistula tract and the anal sphincter, since the same injury could cause malfunction and result in permanent fecal incontinence. If after physical examination we doubt the location of the fistulous tract, we will make a endoanal ultrasound or MRI to determine the relationship between the fistula and anal sphincter.
If suppuration and important exploration inflammation appears difficult, placing a drain (loose fishing line) that the patient take up the final intervention may be necessary.Simple perianal fistulas (travel only through the internal sphincter and the external sphincter bottom), are treated by fistulotomy. In this operation, the surgeon will cut coloproctólogo the skin and part of the sphincter muscle to reach the fistulous tract, making up that way so you can heal from the inside to the outside. It is possible that during the operation the surgeon modify fistula technique if you think may cause risk of incontinence.
In cases of complex perianal fistulas (affects more than half of the external sphincter or have multiple paths) have different techniques. The common aspect of all these techniques is the absence of section sphincter. The simplest techniques are based on the filling of fistulous of different materials (fibrin glue injection or plugs) seeking healing path. At other times we will have a flap endoanal advance in order to obliterate the internal fistulous orifice or technical LIFT (ligation of the fistula in the intersphincteric space). These techniques, while protecting the anal continence, have varying chances of recurrence of the fistula.
Prevention of fistulas
Most fistulas occur by a blockage of glands located inside the anal canal. There are no measures to prevent this obstruction, but it is important valuation and correct treatment by the surgeon before any suspicion of perianal abscess to prevent the development of complex fistulas. In the same sense the correct treatment of anal fissures, which sometimes are the beginning of a subsequent fistula is important.
Edited by Roser Berner Ubasos.