Intrarenal reflux and renal damage.

The retrograde flow of dye from the calices into the collecting tubules (intrarenal reflux) seen during cystrography in children and its effect on the kidneys were evaluated. A retrospective analysis was made of 175 patients with excretory urograms revealing cortical atrophy. Of these patients 68 per cent had cystograms revealing vesicoureteral reflux. Intrarenal reflux was seen in 8 patients less than 6 years old, an incidence of 13.5 per cent in that age group. There was a high correlation, 7 of 8 or 87.5 per cent, between the areas of intrarenal reflux, and associated renal cortical atrophy and calicectasis. Intrarenal reflux provides a pathway by which bacteria and hydrostatic pressure may produce injury to the renal parenchyma. The presence of intrarenal reflux is an absolute indication for ureteroneocystostomy.