Vesicoureteral reflux and renal scarring in children

Vesicoureteral reflux (VUR) is the most common congenital anomaly of the urinary tract. The gold standard for diagnosing VUR is a voiding cystourethrogram (VCUG). According to the International Reflux Grading Scheme, the severity of VUR is classified as grade I–V. It is diagnosed in 30–40 % of children with a urinary tract infection (UTI). VUR may be an isolated abnormality (primary VUR) or it may occur in association with other congenital anomalies of the kidney and urinary tract (CAKUT), including renal dysplasia and obstructive uropathy. VUR may also be noted secondary to bladder dysfunction such as neurogenic bladder or other obstructive anomalies (e.g., posterior urethral valves) (secondary VUR). An increasing number of children with VUR are being diagnosed during follow-up for antenatally diagnosed renal abnormalities and no preexisting history of UTI. Renal scarring associated with VUR is called reflux nephropathy (RN). RN is categorized as “congenital,” which is a result of abnormal renal development leading to focal renal dysplasia, or “acquired” as a result of pyelonephritis-induced renal injury. Complications of RN in pediatric patients include proteinuria, hypertension, and end-stage renal failure (ESRF).