1980 Volume 71 Issue 7 Pages 681-686
Double inferior vena cava is a relatively rare variation. As we have experienced two such cases recently, we report in this paper our observations obtained chiefly by computed tomography (CT).
Case 1, a forty-nine-year-old man, was admitted complaining of anorexia, general malaise and weight loss. Excretory urogram showed a mass laterally in the left kidney. CT scans difined a mass arising from anterolateral aspect which was considered to be consistent with a renal carcinoma. In addition, two round structures were found on both sides of the aorta of prevertebral space. Subsequent contrast-enhanced scans showed that the round left prevertebral structure was contrast density and received the left renal vein. Inferior vena cavogram demonstrated double inferior vena cava, and the right inferior vena cava joined with the left inferior vena cava at the level of the twelve thoratic vertebra.
Case 2, a thirty-six-year old woman, was admitted for investigation of left renal bleeding. Excretory urogram was normal; however, inferior vena cavogram demonstrated double inferior vena cava joined by interiliac vein. On CT scans, three round prevertebral structures which represent the right inferior vena cava, aorta, the left inferior vena cava were found, and the left inferior vena cava joined with the right inferior vena cava at the level of the upper pole of the kidney.
When two round structures were found on both sides of the aorta by CT scans, it is required to differentiate double inferior vena cava from enlarged para-aortic lymph nodes. In our cases differentiation could be made based on the fact that the right and left renal veins flowed into the right and left vena cava separately and that the density was increased on CT after contrast enhancement. In addition, the findings of confluence of the left inferior vena cava with the right inferior vena cava at the level of the upper pole provide some information.
It is recommended that urologists should evaluate the retroperitoneal venous anatomy by means of CT and vena cavography before operations are made to the inferior vena cava or its surrounding area in such a case as radical nephrectomy, taking into consideration the possibility of the variation of double inferior vena cava.
