Observations on the small kidney associated with vesicoureteral reflux.

Of 63 patients with reflux and renal atrophy renal dysplasia was found in 9.5 per cent. Pyelonephritis was apparent in 81 per cent 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.