Surgical treatment is always used for the treatment of anal fistula. At the level of the anal canal, there are small glands, which if their exit is blocked can produce abscesses, and a significant proportion of these can become fistulas. This is a duct that communicates an area at the level of the perianal skin with the interior of the anal canal, where its path can cross the two sphincters of the anus.
Therefore, in most cases, anal fistula is the result of a perianal abscess. In a small proportion of them, they are due to other processes such as Crohn’s disease, sexually transmitted diseases, trauma, tuberculosis, cancer or diverticula.
Types and treatment
Depending on their involvement of the sphincteric apparatus, we differentiate between two types of anal fistulas: simple fistulas, which affect less than 50%, and complex fistulas, which affect more than 50%. Simple fistulas are treated by means of a fistulotomy, in which the skin and muscle up to the fistula path are cut, making it an open groove.
In the case of complex fistulas or reproduced (multioperated) fistulas, there are several therapeutic options. The Setton can be applied in those cases in which the entire tract cannot be excised due to its relation with the sphincter or in those cases in which there is an acute inflammatory component, with associated abscess, an elastic silicone band is left (in the case of Crohn’s disease or high suspicion), or thick silk thread, in order to prevent the fistula from closing falsely, as well as to tighten the fistula. The so-called Flap or advancement flap can also be performed, in which the fistulous tract is first excised from the external fistulous orifice to the sphincteric apparatus, and then the fistulous orifice is closed internally by means of a mucosal autograft.
Other more recent procedures range from the application of biological glues, or synthetic biocompatible materials, or the application of stem cells within the fistulous tract, with results yet to be analyzed, especially in the long term.
Symptoms
Pain and inflammation around the anus and during or after bowel movements are symptoms of anal fistula. Bleeding, bloody or foul-smelling discharge, or irritation of the skin around the anus are other indicators that something is wrong. Their diagnosis varies depending on whether they are simple or complex. In non-complex fistulas, a clinical history, digital rectal examination or rectoscopy may be sufficient. In complex fistulas, however, in addition to these measures, other complementary explorations such as endoanal ultrasound, magnetic resonance imaging and anorectal manometry are required.