Pressure effects of urinary reflux studied with renal autotransplantation and pyelocystostomy

The pressure effects of urinary reflux on renal structure and function were studied using a canine model in which the kidney was autotransplanted to the iliac fossa and the urine drained through a pyelocystostomy. This provided grade III reflux of urine (distention of the renal pelvis and calyces). A control group of nonrefluxing animals with the ureter and ureterovesical valve intact was studied in an identical fashion, and all animals were observed for one year. The reflux of sterile urine was not associated with any impairment of the inulin clearance or transport maximum of para-aminohippuric acid. There were no histologic abnormalities of glomeruli, tubules, or interstitium noted in the animals exposed to sterile reflux, nor were any differences found between the study and control groups. The transmission of bladder pressures into the renal pelvis and calyces during reflux is considered an unimportant factor in explaining the renal damage noted from sterile reflux of short duration in adults. The pyelocystostomy provides a satisfactory means of urinary drainage, and may be used effectively to study the properties of urinary reflex.