Vesicoureteral reflux (VUR) is the reverse flow (reflux) of urine back into the ureters and kidney from the bladder where urine is stored just before it is released from the body (urination). Normally, there should be no backflow of urine. This protects the kidney from any possible infected urine stored in the bladder. The abnormality in VUR is incompetent valves at the junction between the bladder and ureters. There is weakness of bladder at the site of ureteral entry and the trigone. This condition may lead to recurrent urinary tract infections UTI and inevitably infections of the kidney (pyelonephritiis). The ureteral orifices enter at the outer edges of a ridge, and this ridge forms the upper portion of the trigone.
This disorder is important to look for in children who have recurring urinary tract infections (UTI). This disorder will be the cause in 50% of children who have UTIs.
The ureters are two long muscular tubes which travel from the kidneys to the bladder. Normal ureteric parastalysis propels the urine forward into the bladder. As the ureter enters the bladder, it tunnels between muscle layers in the bladder. The ureters enter at an angle so part of the ureter is embedded into the bladder wall . It does not enter directly at 90 degrees, instead it enters to outer muscular layer of the bladder, tunnels in between the outer and inner muscular layers and then enters the bladder. This submucosal tunnel is believe to be the primary mechanism to prevent reflux; a shorter submucosal tunnel is more likely to result in VUR.
The symptoms of reflux can be categorized:
The major cause of VUR is weakness of the trigone and the ureteral musculature in the bladder wall. This can be due to several reasons.
On physical examination by a physician, a distended bladder may be felt in patients with spinal cord injuries. The patient with symptomatic pyelonephritis will have pain located in the flank area, and boys with posterior urethral valves will have a thickened bladder which may be felt during exam.
More than half of children with VUR can be treated non-surgically while adults will require a surgical procedure. Resolution of reflux depends on the grade of reflux. While grade 1 reflux will spontaneously resolve in 90% of patients in 5 years, grade 4 reflux will resolve in approximately 50% of patients. Patients with grade 3 to 5 reflux are treated surgically. Patients who present at an older age, bilateral vesicoureteral reflux and voiding dysfunction are less likely to have spontaneous resolution.
The reason this disorder is important to diagnose is because it can lead to permanent kidney damage in two ways.
All patients, including children and adults, have a very good prognosis. Those with fairly normal urinary tracts do well with conservative treatment, and those needing surgery also have good results. Only those who have significant kidney damage when they see a doctor are those who do not do quite as well. It is emphasized that when a child has recurrent UTIs that they should seek medical attention.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts and supports research to help people with urologic diseases, including children. The NIDDKs Division of Kidney, Urologic, and Hematologic Diseases (DKUHD) maintains the Pediatric Urology Program, which supports research into the early development of the urinary tract. The DKUHD currently supports several researchers working to evaluate current treatments for VUR, particularly the use of antibiotics to prevent infection.
American Urological Association Foundation
1000 Corporate Boulevard
Linthicum, MD 21090
Phone: 1–800–828–7866 or 410–689–3700