Urinary fistula at a glance
A urinary fistula is an abnormal opening in an organ of the urinary tract or an abnormal connection between a urinary tract organ and another nearby organ (often the vagina).
Urinary fistulas cause incontinence and/or infection.
Urinary fistulas often occur after surgery, from trauma, due to certain diseases, or because of radiation treatment.
The most common urinary fistulas occur after damage to the bladder during such abdominal or pelvic surgeries as hysterectomy and caesarean section.
Most urinary fistulas are repaired with surgery.
What is a urinary fistula?
A urinary fistula can be an abnormal opening between urinary tract organs that process urine and carry it out of the body (kidneys, ureter tubes, bladder, urethra). Urinary fistulas can also form an abnormal connection between a urinary tract organ and another nearby organ such as the vagina or colon. Vagina/urinary organ connections are often called vaginal fistulas.
Essentially, a fistula is a hole in the bladder, vagina or other organ that allows urine, stool or other matter to pass where it should not. The result can be feces and urine leaking from the vagina due to that abnormal connection.
Numerous types of fistula are possible:
- A vesicovaginal fistula opens between the vagina and the bladder. This is the most frequent kind of urinary fistula in women. This occurs most often because of a previous hysterectomy. Sometimes a difficult labor can cause a vesicovaginal fistula.
- An enterovesical fistula opens between the bladder and bowel. This is another of the most common urinary fistulas.
- A vesicouterine fistula opens between the bladder and the uterus.
- A ureterovaginal fistula opens between the vagina and ureter (the tube that carries urine between the kidneys and bladder). Most ureterovaginal fistulas occur because of prior hysterectomy or other pelvic surgery.
- A urethrovaginal fistula opens between the vagina and the urethra (the tube that takes urine out of the body).
- A colovesical fistula opens between the bladder and the colon.
- A rectovaginal fistula opens between the vagina and the rectum.
Fistulas are most common in females. Males sometimes experience other types of urinary fistulas as a complication of hypospadias or chordee repair.
Vaginal fistulas are much more common in developing regions without adequate healthcare. In these areas, very difficult childbirth can create tissue damage that sometimes causes fistulas to open.
Fistulas are not very common in developed countries such as the U.S. But they still can occur from one of the causes below.
Causes of urinary fistula
Damage to the tissues of the urinary tract, pelvic region or vagina can create the conditions for a fistula. Urinary fistulas can develop from an injury or accident, a surgery, radiation treatment or (less often) by an infection. The fistula may open after tissue breaks down over time, from days to years.
Fistulas sometimes happen due to:
- Hysterectomy and Caesarean section cause the largest number of vesicovaginal fistulas. Other surgery on the back wall of the vagina, the perineum, anus or rectum can result in a fistula.
- Malignancies in the pelvic region, such as colon or cervical cancers.
- Radiation treatment for pelvic cancer, which can make tissue thin and fragile.
- Inflammatory bowel disease or diverticulitis. Fistulas can be an issue for people with Crohn’s disease or colitis.
- Problems resulting from episiotomy incision for childbirth, such as deep tears or infection.
Symptoms of urinary fistula
Fistulas usually are painless. Most people become aware that they have a fistula because of their symptoms. These symptoms might include:
- Fluid leaking from the vagina.
- Continual leakage of urine from the vagina.
- Foul-smelling gas or discharge from the vagina.
- Feces leaking into the vagina.
- Frequent urinary tract infections (UTIs).
- Passing gas from the urethra while urinating.
- Irritation in the vulva area.
- Abdominal pain.
Diagnosis of urinary fistulas
To understand an individual’s fistula, the physician first will conduct an examination. He or she will discuss the patient’s medical history to determine the possible cause of the fistula or other risk factors. The doctor probably will perform a pelvic examination.
The physician may recommend additional tests to determine the precise location of the fistula and the best way to treat it. These tests might include:
- A urine sample will be sent to a lab for analysis. This test checks for infection or other issues in the urinary tract.
- Complete blood count. Another way to look for indicators of infection.
- Excretory urogram. This test uses a contrasting dye injected into the urinary tract and x-rays to examine the bladder.
- Dye test. The patient’s bladder is filled with a dye and the patient coughs or bears down. The doctor then can look for bladder leakage from a fistula by checking for dye in the vagina.
- A physician can use a cystoscope (a long, thin device with a camera) to view inside the urethra and bladder to look for fistulas or other damage.
- Retrograde pyelogram. Similar to the excretory urogram, this test uses dye and x-rays to check specifically for leakage between the vagina and a ureter.
- A fistulogram is an x-ray image specifically of the fistula(s) that can indicate whether one or more fistulas exist, and which organs the fistula affects.
- Flexible sigmoidoscopy. A physician uses a sigmoidoscope (a thin, flexible tube with a tiny camera) to view the interior of the anus and rectum to check for fistulas or other damage.
- Computerized tomography (CT) urogram. This test is similar to an excretory urogram, but uses dye injected into a vein so the physician can evaluate the vagina and lower urinary tract. The images are created via CT scan rather than x-ray.
- Magnetic resonance imaging (MRI). MRI can create detailed images of internal organs and tissues, helping a physician locate a fistula, determine its size and evaluate how it might be changing.
- Cystogram: Bladder fills with contrast dye to evaluate for the location of urinary leakage.
The physician will use these tests to determine the type, location and severity of the fistula. Then he or she can recommend treatment options.
Treatment of urinary fistula
Some fistulas may only require conservative therapy. However, most fistulas need surgery to repair them.
Some simple fistulas may be able to heal on their own. This might be possible when the fistula is small and the tissue around the fistula is healthy. For instance, where tissue has not been damaged by radiation therapy or cancer.
To allow a fistula to heal, a doctor may try to help a person’s urinary tract function correctly without urine passing through the fistula. Some patients might need to use a urinary catheter to drain the bladder. People with an ureterovaginal fistula might have a small stent (a tube that holds the ureter open) placed in the ureter. This stent can help urine flow correctly from the kidneys to the bladder while the fistula heals.
Most fistulas require surgical repair. The type and location of the fistula will determine the type of surgery. Some surgeries are done through the vagina and some are done through the abdomen. Some cases can be corrected with laparoscopic surgery, which uses only small incisions, or with robotic surgery involving very precise movements.
The goal of surgery is to repair the fistula so that healthy tissue can grow and close the fistula opening, restoring normal function of the organs that are affected. The surgeon will work to remove damaged tissue and any other material (such as a tumor) that could be affecting the fistula.
Before surgery, the physician will work to make the tissue in the area of the fistula as healthy as possible. This may include medications or wound care to help the tissue heal.
If the fistula is large and involves the bowel or colon, the doctor may recommend a colostomy before the surgery. This procedure will keep the fistula clear for the surgery. Once the area of the fistula heals, the doctor usually is able to remove the colostomy.
After the fistula repair surgery, most patients will have a catheter in the bladder for a few weeks. The catheter can be removed once the fistula area has healed.