EXPERIMENTAL STUDIES ON LIGATION OF VENA CAVA CAUDALIS

WITH SPECIAL REFERENCE TO DEVELOPMENT OF COLLATERAL VENOUS PATHWAYS AND EFFECTS ON GENERAL CIRCULATION AND RENAL FUNCTION

Abstract

The author investigates the modes of development of collateral venous pathways and the effects on general circulation and renal function following ligation of the vena cava caudalis, because in radical surgery of the kidney ligation or resection of the vena cava inferior became sometimes necessary.
In 59 adult mongrel dogs the vena cava caudalis was ligated through following 4 methods: Group I, ligation below the level of both renal veins; Group 2, oblique ligation tying the point above right renal vein and the point below left renal vein; Group 3, oblique ligation tying the point above left adrenal vein and the point below right renal vein; and Group 4, ligation above the level of left adrenal and right renal veins. Modes of development of collateral venous pathways were investigated by venography and autopsy. Circuratory changes were examined by measurements of venous pressure and by electrocardiography. Renal damages were studied by intravenous pyelography, determination of blood chemistry and histological examination.
The results are as followed:
(I) Survival rates of groups 1, 2, 3, and 4 were 75%, 50%, 36.6% and 50%, respectively. Early deaths following the ligation were found to be due to diminition of returning blood volumes to the right auricle and acute renal failure. There was no difference of survival rates between male and female dogs.
(2) Maximal venous pressures of the versa saphena parva were measured within 24 hours after the ligation. They returned nearly to normal within a week. The results of venous pressure, serial venography and chemical data of the blood indicated that collatral venous pathways would be accomplished one to two after the ligation.
(3) Main collateral venous pathways were verified to be vena vertebralis, venae lumbales ascendens, venae lumbales and vena azygos in every group of the experiments. In addition to them, somtimes, vena spermatica interna, veins of the abdominal wall, versa subcostalis, venae intercostales and right and/or left retroperitoneal veins (vena circumflexa ilium profunda-vena phrenica inferioradrenal vein) became also collateral pathways. In the early stage after the ligation dilatations of veins of the abdominal wall and retroperitoneal veins were marked, but they were subsided gradually according to the development of collateral pathways through vena spermatica interna. Dilatation, elongation and tortuosity of vena ovarica were more marked than vena testicularis.
(4) Any difference of histological and pyelogrphic findings between right and left kidneys was not observed after restoration from renal damages by accomplishment of perirenal collateral venous pathways, even if there had been a temporary venous congestion of the kidneys.
(5) Any marked post-ligation sequlae was not observed in all survival cases of the experiment.