Vesicoureteral Reflux

Signs and Symptoms

Vesicoureteral reflux is the abnormal backflow of urine from the bladder into the ureter, one of the two tubes that drain urine from the kidneys to the bladder, and up to the kidney. It is the most common problem found in children with urinary tract infections. Reflux is found in 20 percent to 50 percent of children who have had a urinary tract infection. It is dangerous because it allows bacteria that might be in the bladder to reach the kidney. This can cause a kidney infection or pyelonephritis, which can lead to kidney scarring or other damage.

Normally, the ureter enters the bladder in such a way that urine isn't allowed to back up to the kidney. Reflux occurs when the ureter enters the bladder abnormally. The problem results because the muscle backing of the bladder doesn't completely cover the ureter and urine flows back toward the kidney.

Reflux or backflow also occurs because of other problems such as dysfunctional voiding, neurogenic problems or problems with nerve tissue in the bladder or other secondary causes.

We don't know how reflux is transmitted, but there is a very high rate of reflux among siblings - about 40 percent. Younger siblings are at a much greater risk than older siblings. The fact that many affected siblings have no history of urinary tract infection symptoms - although evidence of infection may be found on investigation -- suggests that there may be two different disease processes at work. We recommend that young siblings of refluxers be screened for reflux.

Diagnosis

Reflux usually is diagnosed in one of two ways.

• Children who have a urinary tract infection, which has been confirmed by a lab test, have a contrast X-ray evaluation called a voiding cystourethrogram. This study gives important information regarding the shape and size of the bladder, the bladder neck or opening, the urethra and the tubes or ureters that drain the urine from the kidneys into the bladder. If reflux is present, contrast material instilled into the bladder will backflow into the ureter and kidneys.

• Ultrasound during pregnancy may reveal a fetus with dilated kidneys. If this occurs, a VCUG is done soon after the birth of the baby.

It is especially important to diagnose and treat reflux in infants and small children since most of them will develop another urinary tract infection. Waiting until a child has had two or more urinary tract infections before having an evaluation increases the risk of permanent kidney damage or scarring.

Other tests may include:

• Kidney and Bladder Sonogram -- Otherwise known as "jelly-on-the-belly, this test is routinely recommended prior to the VCUG. The sonogram test, also called an ultrasound, is done to outline the kidneys, ureters and bladder. It also looks for less common urinary tract defects that can cause infections or kidney dilation. The test doesn't require radiation and is painless.

• Kidney (Renal) Scan -- This test may be done if the above tests are abnormal or if repeated fever-causing infections have occurred. It shows the actual function and drainage of the kidneys. A kidney scan also can show if there is kidney damage or scarring from a previous urinary tract infection.

• Nuclear Cystogram -- This test is very similar to the VCUG; however, it has less radiation and is very sensitive for reflux. The VCUG is the preferred initial test for diagnosing reflux because it provides a clearer picture of the lower urinary tract and therefore can rule out other less common abnormalities, as well as grade the reflux for severity. The nuclear cystogram, however, is the recommended test for subsequent follow-up to treat reflux after the diagnosis has been made by the VCUG. The nuclear cystogram also is used as a screening test for siblings of kids who have reflux.

Reflux is graded on a scale of one to five, with one being a mild form and five being severe, as determined by the VCUG. The degree of reflux determines how to treat the child. More severe grades are less likely to clear up spontaneously and have a higher incidence of renal damage if not treated.

Treatment

Reflux is treated either with medication or surgery, based on the degree of reflux, the child's age, the number and severity of urinary tract infections, and the amount of damage to the kidneys seen on X-ray studies. As part of treatment, your child will receive an antibiotic in a daily low dose. These antibiotics are very specific for the urinary tract and have very few side effects. The specific type of antibiotic will depend upon your child's age and allergies.

Medical Therapy

Medical therapy is based on the knowledge that most reflux will resolve on its own as the child grows. It requires daily, low-dose antibiotics taken orally. An ultrasound and cystogram of the kidneys will be performed annually to see if the reflux has resolved. If the reflux persists for several years without change in the grade, surgery may be considered. If your child continues to have fever-causing urinary tract infections while taking antibiotics, then surgery should be considered. Again, the goal is to prevent potential scarring or damage from each infection.

Surgical Therapy

Surgery would be performed if your child has a higher grade of reflux, fever-causing urinary tract infections despite being on antibiotics and signs of kidney damage due to repeated infections. Surgery also may be discussed when, after repeated VCUGs, your child's condition doesn't improve over time. In the surgical procedure, the refluxing ureter or urinary tube is repositioned or re-implanted in the bladder wall. The end of the ureter is surrounded by bladder muscle in this new position in the bladder, which prevents urine from "backing-up" or refluxing toward the bladder. Your child will be in the hospital for three to four days. He or she will still need to take daily antibiotics following the surgery until the bladder and ureter are healed. An ultrasound will be performed about a month after surgery. A VCUG may be performed six months following surgery.