Observations on the small kidney associated with vesicoureteral reflux.

Of 63 patients with reflux and renal atrophy renal dysplasia was found in 9.5%. Pyelonephritis was apparent in 81% of the atrophic lesions. Urinary obstruction or ectasia was apparent in each case with dysplasia and only 2 were associated with histologic evidence of pyelonephritis. Pyelonephritis appears to be a major causal factor in atrophy occurring in renal units with reflux. Early urinary tract obstruction or distension may predispose to renal dysplasia.