Intrarenal reflux--papillary morphology and pressure relationships in children's necropsy kidneys.

A radiological study of the necropsy kidneys of 100 children was made. Morphologically it was shown that compound or fixed papillae predominate in the upper group of calyces and to a lesser degree in the lower group, whilst simple papillae occurred in the middle group. Pressure studies showed that intrarenal reflux occurred in compound papillae at lower pressure than in simple papillae and that lower pressures were required to produce intrarenal reflux in the first year of life.