Recurrent intracaval renal cell carcinoma: the role of intravascular ultrasonography. The presence of extension into the vena cava does not preclude curative resection for extensive renal cell carcinomas. However, preoperative assessment of (1) the proximal extent of the tumor and (2) the degree of adherence within the vena cava is necessary to plan operative strategies. The following report describes the successful use of intravascular ultrasonography in the preoperative evaluation of a patient with recurrent renal cell carcinoma with vena caval extension. 