EXPERIMENTAL HYDRONEPHROSIS

Abstract

During the last fifty years many investigators have turned their attention to the study of the effect of increased intra-ureteral pressure on the kidney parenchyma.Much of the work has been carried on in an effort to ascertain the effect of ureteral ligation, with the result that the pathologic processes involved were found to follow a definite sequence.Then again, the relation of these pathologic lesions to renal function has been studied in various ways, usually on a single kidney with the opposite organ intact.With the introduction of newer methods for the study of renal function, particularly in the last fifteen years, we have thought it of interest to investigate the conditions brought about by subjecting a kidney to back pressure while it was still eliminating the waste products of metabolism.By partially obstructing one ureter with a small rubber band and removing the opposite kidney, Keith and Snowden1 demonstrated changes in renal function along with the development of hydronephrosis.Under these conditions the single kidney, subjected to increased intra-ureteral pressure, must necessarily carry on the total renal excretion.Functional changes were to be expected.Whether similar changes would be brought about by the partial occlusion of both ureters seemed to be a matter for investigation, since such a pro¬ cedure would more closely resemble the effects produced by obstruc¬ tions in the lower urinary tract that are so frequently observed clin¬ ically.The chief object of the investigation was to study functional changes that might occur from day to day in an animal when the only deviation from normal was an increased intra-ureteral pressure.Two types of renal insufficiency were observed after partial occlu¬ sion of the ureters : first, an acute type with symptoms of severe renal insufficiency which soon resulted in death ; second, a chronic condition in which the kidneys might show little or no functional change for a considerable period, but acute renal insufficiency and death occur later.In a few experiments, recovery of function was studied after the removal of its obstruction.