Necrosis of the Renal Pelvis Associated with Obstruction of the Ureters *

A previous report25 described massive hemorrhage and accumulation of turbid fluid in the subcapsular and perirenal tissues after ligation of the ureters in dogs. More detailed study has shown that these lesions result from extension of necrosis from the fornices of the pelvis through the renal parenchyma with consequent leakage of the retained fluid into the surrounding tissue. The necrosis may also extend into one of the large veins in the wall of the pelvis with resultant hemorrhage into the peripelvic, renal, and perirenal tissues, provided that the eroded vein wall is only partly occluded by thrombus. These changes rarely tollow the occlusion of a ureter if the kidney and ureter of the opposite side are functionally adequate, for under such circumstances necrosis of the kidney and of its pelvis is either minimal or entirely absent. Also, this type of necrosis has not been observed after ligation of both renal arteries; it does, however, follow ligation of the renal veins. The same lesions, i.e., necrosis of the renal parenchyma and particularly of the pelvic portions of the pyramids, including the fornices of the pelvis, have been observed in man in cases of acute urinary obstruction associated with cancer of the bladder and with sulfapyridine therapy. These findings provide a possible explanation of the so-called "Massenblutungen ins Nierenlager" and demonstrate a pathway for infection from the urinary tract to the blood stream. Experimental and clinical data are presented below.