Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into one or both ureters and then to the renal calyx or kidneys. Urine normally travels in one direction (forward, or anterograde) from the kidneys to the bladder via the ureters, with a 1-way valve at the vesicoureteral (ureteral-bladder) junction preventing backflow. The valve is formed by oblique tunneling of the distal ureter through the wall of the bladder, creating a short length of ureter (1–2 cm) that can be compressed as the bladder fills. Reflux occurs if the ureter enters the bladder without sufficient tunneling, i.e., too "end-on". Signs and symptoms
Most children with vesicoureteral reflux are asymptomatic. Vesicoureteral reflux may be diagnosed as a result of further evaluation of dilation of the kidney or ureters draining urine from the kidney while in utero as well as when a sibling has VUR (though routine testing in either circumstance is controversial). Reflux also increases risk of acute bladder and kidney infections, so testing for reflux may be performed after a child has one or more infections. In infants, the signs and symptoms of a urinary tract infection may include only fever and lethargy, with poor appetite and sometimes foul-smelling urine, while older children typically present with discomfort or pain with urination and frequent urination. Causes
In healthy individuals the ureters enter the urinary bladder obliquely and run submucosally for some distance. This, in addition to the ureters muscular attachments, helps secure and support them posteriorly.
Thus VUR not only increases the frequency of UTIs, but also the risk of damage to upper urinary structures and end-stage renal disease. Severity
Vesicoureteral reflux (VUR) is graded according to severity. Grade I – reflux into non-dilated ureter
Grade II – reflux into the renal pelvis and calyces without dilatation
Grade III – mild/moderate dilatation of the ureter, renal pelvis and calyces with minimal blunting of the fornices
Grade IV – dilation of the renal pelvis and calyces with moderate ureteral tortuosity
Grade V – gross dilatation of the ureter, pelvis and calyces; ureteral tortuosity; loss of papillary impressionsThe younger the patient and the lower the grade at presentation the higher the chance of spontaneous resolution. Approximately 85% of grade I & II VUR cases will resolve spontaneously. Approximately 50% of grade III cases and a lower percentage of higher grades will also resolve spontaneously. Treatment
The goal of treatment is to minimize infections, as it is infections that cause renal scarring and not the vesicoureteral reflux. Minimizing infections is primarily done by prophylactic antibiotics in newborns and infants who are not potty trained. However, in children who are older, physicians and parents should focus on bowel and bladder management. Children who hold their bladder or who are constipated have a greater number of infections than children who void on a regular schedule. When medical management fails to prevent recurrent urinary tract infections, or if the kidneys show progressive renal scarring then surgical interventions may be necessary.