Intra-renal reflux.

A new model for the study of intra-renal reflux (IRR) is proposed. The renal pelvis of human kidneys, either obtained from cadavers or removed surgically, was injected, at increasing pressures, with dye solutions to investigate intra-renal reflux. To reproduce physiological conditions as closely as possible, arterial perfusion was performed, either continuously or by means of a peristaltic pump, so that a predetermined pressure in the vascular system could be obtained. Comparison was made between results obtained by this technique and the results reported in the literature and previously recorded by the present authors without any perfusion of the vascular system. Our results show significant diffusion of the vascular system. Our results show significant differences in the threshold of IRR compared to data from experiments in which vascular perfusion was not simultaneously performed. It can be concluded that, under physiological conditions, intrarenal flux occurs at pressures of 40 cm H2O, and pyelovenous reflux at pressures of 60-70 cm H2O.