[The invasion of kidney tumors into the veins]

Comprehensive angiographic examinations of 101 patients operated on for parenchymatous cancer recorded intravenous invasion of the tumour in 29 per cent of the examinees. Roentgenological, macro and microscopic investigations of intraorganic vascular architectonics were studied on 52 removed tumour-affected kidneys. The findings evidenced the outflow of the major blood amount from the tumorous tissue through the collateral collector and subcapsular veins to paranephric ones with a subsequent dilatation of the latters. Arteriographically evidenced tumorous lacunae turned to be muscle-free arterial vessels different from arteriovenous shunts. So the concept of shunt frequency is doubtful and embolism of giant hypervascular tumours of the kidney without embolism of pulmonary arteries is possible. More common passage of tumorous thrombi into vena cava inferior in case of right-sided tumours can be explained by a shorter length of the right renal vein. Besides, the left free growth of the thrombus is hindered by pulsing "aortomesenteric forceps" that enclosed the left renal vein.