Fistula repair

Anatomy or system affected: Abdomen, anus, bladder, blood, gallbladder, gastrointestinal system, intestines, reproductive system, urinary system, uterus

Definition: The removal of any abnormal passage associated with body sites or tissues

Indications and Procedures

A fistula is any abnormal opening or passage between internal organs or between an internal organ and the surface of the body. Fistulas can occur nearly anywhere in the body, but they are most common in the anorectal portion of the anatomy. Some fistulas may result from congenital defects, while others may be created surgically in association with specific procedures. For example, an arteriovenous fistula may be created to allow the insertion of a cannula (tube) for hemodialysis.

Anorectal fistulas usually begin as an abscess within the anal region or internal crypt that then spreads to adjacent tissue or to the surface of the body. Pain, itching, or tenderness in the region is often the first sign of a problem. The discomfort may be aggravated by bowel movements. Since infection is common, the opening may become purulent (pus-producing).

Treatment of anorectal fistulas usually requires surgery. A crypt hook may be used if the site of the original crypt must be located, though this is often unnecessary. The crypt may also be observed through an anoscope or as part of a proctoscopic examination. Often, digital examination of the anal canal may detect a nodule, representing the abscess itself.

Any abscess must first be drained and treated. If the fistula is small, it may heal itself. The surgical procedure, commonly referred to as a fistulectomy, is a relatively simple operation carried out under general anesthesia. The fistula must be reduced or removed. Surgical repair begins at the primary opening. Generally, the entire tract is opened to allow for proper drainage of infectious material and promote healing. If the surgery is carried out properly, the incision should heal relatively quickly.

Difficult labor in women may create a variety of fistulas. A vesicovaginal fistula, created between the urinary bladder and the vagina, may be indicated by the presence of urine in the vaginal tract. As with any opening to the surface of the body, infection may develop. Likewise, a rectovaginal fistula, between the rectum and vagina, was formerly a possible serious complication of difficult childbirth. Such openings, like any fistulas, must be opened, drained, and sutured for healing.

Fistula formation may also be internal, as in biliary fistulas between the gallbladder and intestine. Such connections can occur as a consequence of gallstones, ulcers, or tumor formation. Often, the major symptom may be an intestinal blockage resulting from the stone or tumor itself. Bile may leak from the gallbladder into the peritoneum or body cavities, resulting in infection. Therapy for such fistula formation first requires an analysis of the channel itself. If the fistula is external, contrast material may be injected into the site to analyze the tract. If it is internal, the extent of the tract may require cholangiography, the injection of a radiopaque material to outline the bile duct. General surgery is required for the proper correction of any underlying problem.

Uses and Complications

Surgical repair of a fistula has a number of functions, in addition to the elimination of the fistula itself. The goal of repair is to support the healing process, while at the same time attempting to maintain the normal function (and appearance, when applicable) of the tissue.

The anal fistula represents one of the more common types. Frequently, it begins as an abscess or break in the anal or rectal wall. The underlying cause is often inflammation of the colon as a result of ulcerative colitis or Crohn’s disease, an autoimmune disease that can cause ulceration of the intestinal wall. The fistula itself may become chronically infected, resulting in pain and discomfort. Cancer development in the area of the fistula, while uncommon, has been known to occur.

The major complication of anorectal surgery to repair the fistula is delayed healing. If not completely drained or covered, the area may continue to become infected. If the fistula is deep, damage to muscles during surgical repair may result in incontinence. Assuming that the fistula does not recur and postoperative care is properly provided, however, the prognosis is generally excellent.

Surgical procedures can also be used in the intentional formation of a fistula. For example, a site must be prepared for insertion of a cannula to carry out hemodialysis, the removal of waste from the blood under conditions of renal insufficiency. Generally, such a fistula between an artery and a vein is prepared one to two months prior to insertion of the cannula. The fistula is created either by grafting a section of bovine carotid artery into the site or by using a graft prepared from synthetic material. Proper circulation through the fistula must be monitored to ensure that infection does not develop.

Perspective and Prospects

The development and widespread use of antibiotics in the mid-twentieth century provided a means for the effective treatment of infection, which is the major complication associated with fistula development. Fistulas may result in abscess formation or may be secondary to problems elsewhere, as with Crohn’s disease. Better treatment of those infections associated with fistula formation, such as tuberculosis, has reduced their incidence. Likewise, proper prenatal care has largely controlled fistula development secondary to difficult labor in women.

Bibliography

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Cameron, John L., and Andrew M. Cameron, eds. Current Surgical Therapy. 14th ed., Elsevier, 2023.

“Fistulas.” MedlinePlus, 4 Nov. 2021, medlineplus.gov/ency/article/002365.htm. Accessed 25 July 2023.

Papadakis, Maxine A.., and Stephen J. McPhee, eds. Current Medical Diagnosis and Treatment 2023. 62nd ed., McGraw-Hill, 2023.

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Saibil, Fred. Crohn’s Disease and Ulcerative Colitis: Everything You Need to Know. 3rd ed., Firefly Books, 2011.