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Vesicoureteral reflux

What is Vesicoureteral reflux

Vesicoureteral reflux (VUR) is the medical term for “backwards peeing”. Simply put, when some children urinate the urine not only flows out of the urethra but also backwards through the ureters toward the kidneys. This is a potential danger to the kidney if the urine is infected or if the flow is under high pressure. VUR in children occurs when the ureter is abnormally inserted into the bladder wall. A normal insertion results in a valve-like mechanism thereby preventing flow of urine from the bladder back into the ureter toward the kidney. In VUR the ureter insertion does not create a valve and thus urine can freely flow in a retrograde fashion from the bladder toward the kidney. This happens during embryogenesis (organs forming in the womb during the first 12 weeks of pregnancy).

Diagnosising Vesicoureteral reflux

VUR is usually diagnosed when an infant or child is undergoing radiologic studies after having a urinary tract infection. It is recommended that studies be done in children following a urinary tract infection based upon gender and age risk factors:

  • with the first episode of urinary tract infection in all boys;
  • in girls < 5 years old;
  • and, in older girls that have recurrent infections of the bladder or kidney.

There are several studies that are done: ultrasound; voiding cystourethrography (VCUG); and nuclear cystography. The first test usually performed is the renal ultrasound which can be done as soon as possible after the urinary tract infection is diagnosed. The VCUG is done next, usually 2-6 weeks after infection, although the timing of this test is currently controversial. VCUG is necessary for the diagnosis of reflux. A dye is injected into the bladder through the urethra (via a catheter tube). The flow of the dye is then observed under fluoroscopy (best described as “real-time” video x-rays) by a radiologist. If the dye leaves the bladder and flows toward the kidney, then a diagnosis of VUR is made. There are 5 grades of VUR ranging from mild to severe. Nuclear cystography is similar to VCUG except that it uses less radiation, but is a little less precise. Nuclear cystography is used for yearly follow-up of VUR, or for screening of siblings of children with reflux.

Vesicoureteral reflux Treatment

Treatment of VUR in most cases is with low dose daily antibiotics, usually nitrofurantoin, amoxicillin or trimethoprim-sulfamethoxazole. Corrective surgery may be considered for grade V reflux and for those with recurrent urinary tract infections despite treatment with low dose daily antibiotics. Surgery involves re-implanting the ureter into the bladder wall at a different angle which creates the reflux-preventing valve effect during urination.


Prognosis for children with VUR is excellent. Most children with grade III or less will resolve by school age. Children are usually followed in the pediatrician’s office every 3 to 4 months to monitor the urine for infection. At yearly intervals, they should have follow-up studies using nuclear cystography. For grade IV or V reflux, consultation with a urologist should be made.