Figure 1.

Theoretical model showing how urinary stasis caused by VUR leads to bacterial growth in the renal parenchyma. Macrophages and leukocytes migrate to the interstitium and secrete pro-inflammatory cytokines, resulting in fibrosis and scarring with a progressive decline in renal function and the development of proteinuria and hypertension. In reality, only a minority of children with primary VUR develop scarring.