Vesicoureteral Reflux Specialists  Bernard M. Churchill, MD Steven Lerman, MD, FAAP Jennifer Sandra Singer, MD Ongoing Clinical Trials No Current Trials... Related Research Projects No Current Research Projects...

General Information

Vesicoureteral reflux (VUR) is the backup of urine from the organ that stores urine (bladder) into the tube that carries urine from the kidney to the bladder (ureter) during urination. VUR may result in urine reflux into the renal pelvis, causing distention (hydronephrosis) and kidney damage. In children, this condition is usually caused by an abnormality that is present at birth (congenital) and is often diagnosed during prenatal ultrasound.

Types
There are two types of VUR: primary and secondary. Primary reflux is caused by a congenital (present at birth) abnormality, and secondary reflux is caused by a urinary tract infection (UTI) or an obstruction in the urinary tract.

Reflux is graded according to its severity:

• Grade I results in urine reflux into the ureter only.
• Grade II results in urine reflux into the ureter and the renal pelvis, without distention (hydronephrosis).
• Grade III results in urine reflux into the ureter and the renal pelvis, causing mild hydronephrosis.
• Grade IV results in moderate hydronephrosis.
• Grade V results in severe hydronephrosis and twisting of the ureter.

Causes and Risk Factors

Undetermined genetic risk factors may affect the development of VUR. About one third of patients who have the condition have siblings who are also affected. Siblings of patients with VUR are routinely tested for the condition, even when symptoms are not present.

The most common cause for primary reflux in children is an abnormality in the section of the ureter that enters the bladder (called the intravesical ureter). The intravesical ureter may not be long enough to enable the ureter to close sufficiently to prevent urine reflux, or the ureter may be inserted abnormally into the bladder. This condition often resolves as the child grows and the ureter lengthens.

Other causes of primary reflux include abnormalities in detrusor muscle tissue of the bladder, abnormalities in the location of the urethral opening (e.g., hypospadias), and abnormalities in the shape of the urethral opening.

Secondary reflux is often caused by urinary tract infection (e.g., cystitis) that results in inflammation and swelling of the ureter. UTI may cause vesicoureteral reflux or vesicoureteral reflux may promote the growth of bacteria in the urinary tract, causing UTI. Secondary reflux may also be caused by urinary tract abnormalities (e.g., narrowing, or stricture, of the ureter; duplicated ureters; ureterocele) and obstructions (e.g., UPJ obstruction, stones, tumor).

Signs and Symptoms

The most common symptom of VUR is urinary tract infection (UTI). Other symptoms might include the following:

• Bedwetting (nocturnal enuresis)
• Collection of urine in the renal pelvis (hydronephrosis) Distention in the abdomen (caused by hydronephrosis)
• Failure to thrive
• High blood pressure (hypertension; caused by kidney damage)
• Nausea and vomiting
• Protein in the urine (proteinuria)

Untreated VUR provides access for bacteria to enter the kidneys and may result in kidney infection (pyelonephritis), kidney damage, and progressive renal failure.

Diagnosis

VUR is commonly diagnosed during infancy or childhood as a result of a urinary tract infection (UTI). UTI is diagnosed using urinalysis and urine culture. VUR that causes hydronephrosis (collection of urine in the renal pelvis) is often diagnosed during prenatal ultrasound.

A cystogram (also called cystourethrogram) and a voiding cystourethrogram (VCUG) are performed to determine if an abnormality in the urinary tract is causing reflux. In these procedures, a contrast dye is instilled into the bladder through a catheter and a series of x-rays are taken. Other diagnostic tests used to diagnose VUR include the following:

• Bladder ultrasound (to detect abnormalities that cause reflux)
• Renal ultrasound and renal scan (to evaluate hydronephrosis, kidney growth, and scarring)
• Urodynamic studies (e.g., filling cystometrogram, voiding cystometrogram)

Medication
Treatment for grades I - III VUR includes daily low-dose antibiotics in most patients (e.g., trimethoprim-sulphamethoxazole, amoxicillin, cephalexin) until the reflux resolves or until the child is at least 5 years old. These cases require regular monitoring by a pediatric urologist to diagnose UTI and prevent the condition from worsening.

Surgery
Secondary reflux that does not resolve with antibiotic treatment, or that results in UTI despite antibiotic therapy (called breakthrough infections), and primary reflux that is severe (grades IV and V) require surgery to prevent permanent kidney damage.

Endoscopic (minimally invasive) Surgery
Increasing use of injectable materials (e.g. Deflux) over the last ten years has proven successful, especially in the treatment of low-grade reflux. This procedure is an out-patient procedure that involves injecting a bulking agent into the bladder through a telescope (no incision necessary). This injection is done into the area of the faulty valves where the ureter(s) join the bladder. 

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