Introduction
Fistula tracts represent pathological connections between different organs or tissue layers, which are not naturally present. They arise, for example, as a result of an injury or inflammation or due to a disease. Depending on the organ of origin, blood, pus or other bodily secretions can pass through the fistula tract.
How does a fistula tract occur?
The development of a fistula tract is often based on an inflammatory process in the body. If, for example, an encapsulated purulent inflammation of an organ (abscess) occurs, a fistula tract can develop, through which the body tries to transport the pus away. In some cases, fistulas can also develop from naturally existing ducts.
An example are small anal glands which lead into the rectum. If an inflammation develops there due to immigrating intestinal bacteria, a fistula duct can develop which exits through the skin. The division and growth of cells thus creates a fistula tract that is lined and sealed from the inside.
Depending on the place of origin, body secretions or pus may pass through this fistula. A distinction must be made between such pathological fistula ducts and connecting pathways that have been created by a medical intervention, some of which are also referred to as fistulas. An example of this is the gastric fistula, which is created to artificially feed a person who can no longer swallow food. This fistula tract is artificially created during a gastroscopy. The gastric fistula is also known as percutaneous endoscopic gastrostomy (PEG), which means the passage from the stomach cavity to the body surface through the skin.
What causes a fistula tract?
The cause for the development of a fistula tract is usually either injury or inflammation. In addition, there are congenital fistulas, for example in the case of incomplete regression during embryonic development, but these are not caused by inflammatory processes. In the case of fistulas caused by inflammation, there are certain diseases in which fistula ducts are particularly common.
One example is the chronic inflammatory bowel disease Crohn’s disease. In this condition, centres of inflammation can occur throughout the entire digestive tract. Since all layers of the intestinal wall are usually affected in Crohn’s disease, fistula tracts that originate from the intestinal loops are common in this disease.
These fistulas can grow into another intestinal loop or other organs such as the bladder or vagina. In addition, the ducts can also grow towards the surface of the body so that they exit the skin. Another possible cause for the development of intestinal fistulas are so-called diverticula.
Many adults (especially those who are overweight and not very active) are affected by these diverticula of the intestinal wall. The diverticula can become inflamed, which leads to an acute serious illness, but the bulges can also develop into fistula ducts. Other causes for the development of fistula tracts due to an inflammation are untreated tooth root abscesses or hair root abscesses, for example on the coccyx. Another cause is fistulas that develop as a result of an injury during a medical procedure, for example when the organ wall is accidentally damaged during a colonoscopy. Another possible cause for the development of a fistula tract as a result of a medical intervention is the radiation of a tumor, for example.
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