A fistula (plural: fistulas or fistulae ; from Latin fistula, "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow organs. Types of fistula can be described by their location. Anal fistulas connect between the anal canal and the perianal skin. Anovaginal or rectovaginal fistulas occur when a hole develops between the anus or rectum and the vagina. Colovaginal fistulas occur between the colon and the vagina. Urinary tract fistulas are abnormal openings within the urinary tract or an abnormal connection between the urinary tract and another organ such as between the bladder and the uterus in a vesicouterine fistula, between the bladder and the vagina in a vesicovaginal fistula, and between the urethra and the vagina in urethrovaginal fistula. When occurring between two parts of the intestine, it is known as an enteroenteral fistula, between the small intestine and the skin as an enterocutaneous fistula, and between the colon and the skin as a colocutaneous fistula.Fistulas can result from an infection or inflammation, injury or surgery. Fistulas are sometimes surgically created as part of a treatment, for example arteriovenous fistulas for hemodialysis.Treatment for fistula varies depending on the cause and extent of the fistula, but often involves surgical intervention combined with antibiotic therapy. In some cases the fistula is temporarily covered using a fibrin glue or plug. Catheters may be required to drain a fistula.Globally, every year between 50,000 and 100,000 women are affected by fistula relating to childbirth.
Also known as an ear pit or preauricular sinus. (Q26.6) Portal vein-hepatic artery fistula
(Q38.0) Congenital fistula of lip
(Q38.4) Congenital fistula of salivary gland
(Q42.0) Congenital absence, atresia and stenosis of rectum with fistula
(Q42.2) Congenital absence, atresia and stenosis of anus with fistula
(Q43.6) Congenital fistula of rectum and anus
(Q51.7) Congenital fistulae between uterus and digestive and urinary tracts
(Q52.2) Congenital rectovaginal fistula

T: External causes
(T14.5) Traumatic arteriovenous fistula
(T81.8) Persistent postoperative fistula

Causes
Disease: Infections including an anorectal abscess and inflammatory diseases including Crohns disease and ulcerative colitis can result in fistulas. Fistulas to the anus may occur in hidradenitis suppurativa. In women, fistulas can also occur following pelvic infection and inflammation. Surgical and medical treatment: Complications from gallbladder surgery can lead to biliary fistulas. As well as being congenital or resulting from trauma, arteriovenous fistulas are created purposefully for hemodialysis. Radiation therapy to the pelvis can lead to vesicovaginal fistulas. Persistent gastrocutenaous fistulas can develop after gastrostomy. Trauma: Prolonged childbirth can lead to fistulas in women, in whom abnormal connections may occur between the bladder and vagina, or the rectum and vagina. An obstetric fistula develops when blood supply to the tissues of the vagina and the bladder (and/or rectum) is cut off during prolonged obstructed labor. The tissues die and a hole forms through which urine and/or feces pass uncontrollably. Vesicovaginal and rectovaginal fistulas may also be caused by rape, in particular gang rape, and rape with foreign objects, as evidenced by the abnormally high number of women in conflict areas who have developed fistulae.