In medicine, a fistula (pl. fistulas or fistulae) is an abnormal connection or passageway between organs or vessels that normally do not connect.
Location of fistulas
Fistulas can develop in various parts of the body, including:
- Anorectal fistula: connecting the rectum or other anorectal area to the skin surface. This results in abnormal discharge of feces through an opening other than the anus. Also called fistula-in-ano.
- Arteriovenous fistula or A-V: between an artery and vein
- Biliary fistula: connecting the bile ducts to the skin surface, often caused by gallbladder surgery
- Cervical fistula: abnormal opening in the cervix
- Craniosinus fistula: betwixt the intracranial space and a paranasal sinus
- Enteroenteral fistula: betwixt two parts of the intestine
- Enterocutaneous fistula: betwixt the intestine and the skin surface, namely from the duodenum or the jejunum or the ileum. This definition excludes the fistulas arising from the colon or the appendix.
- Enterovaginal fistula: betwixt the intestine and the vagina
- Fecal fistula: see Anorectal
- Fistula-in-ano: see Anorectal
- Gastric fistula: from the stomach to the skin surface
- Metroperitoneal fistula: betwixt the uterus and peritoneal cavity
- Perilymph fistula: tear betwixt the membranes between the middle and inner ears
- Pulmonary arteriovenous fistula: betwixt an artery and vein of the lungs, resulting in shunting of blood. This results in improperly oxygenated blood
- Rectovaginal: betwixt the rectum and the vagina
- Umbilical fistula: betwixt the umbilicus and gut
- Tracheoesophageal fistula: betwixt the breathing and the feeding tubes
- Vesicovaginal fistula: betwixt the bladder and the vagina
Types of fistulas
Various types of fistulas include:
- Blind: with only one open end
- Complete: with both external and internal openings
- Incomplete: a fistula with an external skin opening, which does not connect to any internal organ
Although most fistulas are in forms of a tube, some can also have multiple branches.
Causes
Various causes of fistula are:
- Diseases: Inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis, are the leading causes of anorectal, enteroenteral, and enterocutaneous fistulas.
- Medical treatment: Complications from gallbladder surgery can lead to biliary fistula. Radiation therapy can lead to vesicovaginal fistula.
- Trauma: Head trauma can lead to perilymph fistulas, whereas trauma to other parts of the body can cause arteriovenous fistulas. Obstructed labor can lead to vasicovaginal and rectovaginal fistulas. Vasicovaginal and rectovaginal fistulas may also be caused by rape, in particular gang rape, as evidenced by the abnormally high number of women in conflict areas, such as that of the Second Congo War, who have suffered fistulae.
Treatment
Treatment for fistulae varies depending on the cause and extent of the fistula, but often involves surgical intervention combined with antibiotic therapy.
Typically the first step in treating a fistula is an examination by a doctor to determine the extent and "path" that the fistula takes through the tissue.
Surgery is often required to assure adequate drainage of the fistula (so that pus may escape without forming an abscess). Various surgical procedures are commonly used, most commonly fistulotomy, placement of a seton (a cord that is passed through the path of the fistula to keep it open for draining), or an endorectal flap procedure (where healthy tissue is pulled over the internal side of the fistula to keep feces or other material from reinfecting the channel). Surgery for anorectal fistulae is not without side effects, including recurrence, reinfection, and incontinence.
It is important to note that surgical treatment of a fistula without diagnosis or management of the underlying condition, if any, is not recommended. For example, surgical treatment of fistulae in Crohn's disease can be effective, but if the Crohn's disease itself is not treated, the rate of recurrence of fistula is very high (well above 50%).