Fistula

FISTULA is an abnormal canal, lined with epithelium or granulations, opening onto the surface of the body or connecting hollow organs with one another. Fistulae are of congenital or pathological origin. Depending on the superficial or deep location of the fistula and its connection with the outside world, fistulae are divided into open and closed, complete and incomplete. Sometimes long, often very tortuous fistulous tracts form leading to the primary inflammatory focus. Often, fistulae are named according to the shape of their external opening, for example, a labial fistula. Congenital fistulae develop due to incomplete closure of clefts and ducts during the embryonic period, for example, a congenital fistula of the neck or an umbilical-vesical fistula (see Bladder, fistulae of the bladder). Pathological fistulae develop: 1) due to injuries and surgical interventions, whether accidental (see Ureter, Urethra) or intentional, for example, an Eck fistula, a bladder fistula after sectio alta (see Bladder); 2) due to inflammatory processes—the majority of intestinal fistulae (see Intestine); 3) as a result of neoplasms—vesicouterovaginal, vesicocervical fistulae. Abnormal connections of glands (kidney, mammary gland, etc.) with the skin surface have the same etiology in their development as pathological fistulae in general, but they more often develop due to inflammatory diseases accompanied by suppuration. A milk fistula forms during purulent mastitis, in which abscesses, especially those lying behind the mammary gland, were not timely and widely opened. Leaving a drain in place for a long time contributes to the formation of a fistula. Through these fistulae, lined with spongy granulations which prevent the wound from adhering and the fistula from healing, milk is discharged in addition to pus. Fistulae can also exist without a connection to an epithelial hollow organ and form after the opening of an abscess on the body surface, which is observed in osteomyelitis, tuberculosis, etc. Foreign bodies can serve as the cause of long-non-healing fistulae. The fistulous tract is lined with granulations or epithelium. The external appearance of a fistula varies depending on the secretion and the cause of origin. Around a gastric fistula, significant dermatitis may form due to the corrosive action of the juice. Urinary fistulae contribute to the overgrowth of the skin and its elephantiasis. Diagnosis of a fistula does not present great difficulties. Already on the basis of complaints and anamnesis, correct conclusions can be drawn. To determine the exact direction of the fistulous tract, probing, radiography with a contrast agent introduced through the fistula, and the injection of various coloring substances are used. As for the treatment of fistulae, it must be said that a certain portion of fistulae can close by themselves; others require minor surgical interventions, such as incision, cauterization, and the removal of foreign bodies supporting the fistula. (Regarding the treatment of fistulae of individual organs, see the corresponding organs.) N. Minin.