A fistula is an abnormal communication between two internal organs, or from an organ to the outside of the body. Infection, inflammatory disease (e.g., Crohn's disease), tumors, trauma, and surgery may lead to a fistula. The gastrointestinal tract (particularly the duodenum), pancreas, bladder, and female genital tract are particularly susceptible.

 

Among the many places in the body where fistulas can occur are:

 

Arteriovenous (between an artery and vein)

Biliary (created during gallbladder surgery, connecting bile ducts to the surface of the skin)

Cervical (either an abnormal opening into the cervix or in the neck)

Craniosinus (between the space inside the skull and a nasal sinus)

Enterovaginal (between the bowel and vagina)

Fecal or anal (the feces is discharged through an opening other than the anus)

Gastric (from the stomach to the surface of the skin)

Metroperitoneal (between the uterus and peritoneal cavity)

Pulmonary arteriovenous (in a lung, the pulmonary artery and vein are connected, allowing the blood to bypass the oxygenation process in the lung (pulmonary arteriovenous fistula))

Umbilical (connection between the navel and gut)

 

Types of fistulas include:

 

Blind (open on one end only, but connects to two structures)

Complete (has both external and internal openings)

Horseshoe (connecting the anus to the surface of the skin after going around the rectum)

Incomplete (a tube from the skin that is closed on the inside and does not connect to any internal structure)