Vesicoureteral reflux

Vesicoureteral reflux (VUR) occurs when urine that dwells in the bladder flows back into the ureters and often back into the kidneys. The bladder is the hollow, muscular organ that stores urine before urination occurs. The bladder has three small openings: two connect the ureters where urine is drained down from the kidneys, and one connects the bladder to the urethra where urine exits the body.

The ureters are funnel-shaped tubes that carry urine from the kidneys. Ureters enter the bladder at a diagonal angle and have a special one-way valve system that normally prevents urine from flowing back up the ureters in the direction of the kidneys. When a child has vesicoureteral reflux, the mechanism that prevents the back-flow of urine does not work, allowing urine to flow in both directions. A child who has vesicoureteral reflux is at risk for developing recurrent kidney infections, which, over time, can cause damage and scarring to the kidneys.

Causes

There are many different reasons why a child may develop vesicoureteral reflux. Some of the more common causes include:

• VUR commonly occurs in children whose parents or siblings have the irregularity.
• Children who are born with neural tube defects such as Spina bifida may have VUR.
• During infancy, the disease is more common among boys because as they urinate there is more pressure in their entire urinary tract. In early childhood, the irregularity is more common in girls.
• VUR can occur in children with other urinary tract abnormalities such as posterior urethral valves, ureterocele, or ureter duplication.
• VUR is more common in Caucasian children than in African-American children.

Symptoms

The following are the most common symptoms of vesicoureteral reflux. However, each child may experience symptoms differently. Symptoms may include:

• Urinary tract infection (urinary tract infections are uncommon in children younger than 5 years and unlikely in boys at any age, unless VUR is present).
• Trouble with urination including urgency, dribbling and wetting pants.
• An abdominal mass may be detected from a swollen kidney.
• Poor weight gain.
• High blood pressure.

The symptoms of VUR may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.

Diagnosis

VUR can often be detected by ultrasound before a child is born. If there is a family history of VUR, but your child has no symptoms, your child's physician may elect to perform a diagnostic test to rule out VUR. Diagnostic procedures for VUR may include:

• Voiding cystourethrogram (VCUG) - a specific x-ray that examines the urinary tract. A catheter (hollow tube) is placed in the urethra (tube that drains urine from the bladder to the outside of the body) and the bladder is filled with a liquid dye. X-ray images will be taken as the bladder fills and empties. The images will show if there is any reverse flow of urine into the ureters and kidneys.
• Renal ultrasound - a non-invasive test in which a transducer is passed over the kidney producing sound waves which bounce off the kidney, transmitting a picture of the organ on a video screen. The test is used to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst, or other obstruction or abnormalities.
• Blood tests.

Treatment:

VUR can occur in varying degrees of severity. It can cause mild reflux, when urine backs up only a short distance in the ureters. Or, it can cause severe reflux leading to kidney infection(s) and permanent kidney damage. Specific treatment for VUR will be determined by your child's physician based on:

• Your child's age, overall health, and medical history.
• The extent of the condition.
• Your child's tolerance for specific medications, procedures, or therapies.
• Expectations for the course of the condition.
• Your opinion or preference.

Your child's physician may assign a grading system (ranging from 1 to 5) to indicate the degree of reflux your child has. The higher the grade, the more severe the reflux.

Most children who have grade 1 through 3 VUR do not need any type of intense therapy. The reflux resolves on its own over time, usually within five years. Children who develop frequent fevers or infections may require ongoing preventive antibiotic therapy and periodic urine tests.

Children who have grade 4 and 5 reflux may require surgical intervention. During the procedure, the surgeon will create a flap-valve apparatus for the ureter that will prevent reverse flow of urine into the kidney. In more severe cases, the scarred kidney and ureter may need to be surgically removed.

New treatments are being introduced, in some cases, for vesicoureteral reflux. Consult your child's physician for more information.