腎細胞癌における腎静脈および下大静脈のComputed Tomographyによる検討

Abstract

Renal cell carcinoma not rarely invades the renal vein and inferior vena cava with formation of tumor thrombus. On the other hand, congenital anomalies of these venous channels are occasionally encountered. At the time of surgery of renal cell carcinoma, therefore, preoperative evaluation of the renal vein and inferior vena cava is desirable. In 22 cases of renal cell carcinoma treated at the Jikei University Hospital during 16 months period from Jan. 1979 to Apr. 1980, the renal vein and inferior vena cava were examined by computed tomography (CT). Intravenous tumor thrombus was diagnosed in 4, double inferior vena cava in one and retroaortic left renal vein in one. All these CT diagnosis were confirmed to be correct by surgery. Three of tumor thrombus cases showed involvement of inferior vena cava. CT findings included dilated vein in 4 and filling defect after contrast enhancement in 2. In double inferior vena cava, CT at the level of the upper pole of kidney showed the left inferior vena cava traversing in front of the aorta and conjoining the left inferior vena cava, CT at the level of renal vein the left renal vein draining into the left inferior vena cava and CT at the lower level two round inferior vena cava with the aorta between them. It was a diagnostically useful finding that the left inferior vena cava was markedly stained in CT after contrast enhancement just as the aorta and the right inferior vena cava. In retroaortic left renal vein, CT showed the left renal vein running behind the aorta and draining into the inferior vena cava. Preoperative information on congenital anomalies of the renal vein and inferior vena cava or tumor thrombus and its extension are very important particularly for radical surgery to be conducted safely without postoperative complications. Computed tomography is quite useful in evaluation of morbid state of the renal vein and inferior vena cava.