Collateral Circulation, Renal Function and Histology after Experimental Obstruction of Renal Veins

¹ Angiology Research Laboratory, Touro Research Institute and the Department of Medicine, Tulane University, School of Medicine, New Orleans, Louisiana

Changes in renal excretion and histology were studied for varying periods following unilateral or bilateral ligation of the renal veins in female rats. Collaterals were studied by plastic corrosion models of alternate rats in each series. Proteinuria lasted less than one week. The most common histologic findings were infarction, hemorrhagic changes and congestion. Return toward normal was related to the development of functioning venous collaterals which began from one to three days following ligation, depending on the site of ligation. Since the ovarian vein is a tributary of the left renal vein, ligation proximal or distal to their junction made a significant difference in the effective collateralization on that side. The left kidney appeared to withstand ligation better than the right which manifested more abnormalities even when it was the unligated kidney. With bilateral renal venous ligation, survival appeared to be closely related to the site of ligation, especially of the left renal vein. Although the rate of development of collaterals and the duration of functional and histologic changes differ from those reported for thrombotic obstruction of the renal veins, clinical implications may be recognized.