The Detection of Renal Carcinoma Extension into the Renal Vein and Inferior Vena Cava: A Prospective Comparison of Venacavography and Magnetic Resonance Imaging

Abstract

Accurate preoperative evaluation of the inferior vena cava and renal vein in patients with renal cell carcinoma is mandatory to plan a successful surgical approach. The presence of venous extension may alter transfusion and anesthetic requirements, as well as require the addition of a vascular surgeon to the operative team. Venacavography traditionally has been considered the most reliable method to identify tumor thrombus, although magnetic resonance imaging has been proposed as a possible noninvasive alternative. We compared prospectively the accuracy of these 2 methods in 44 consecutive patients with renal cell carcinoma who subsequently underwent nephrectomy. Of the 44 patients 11 (25%) had tumor extension into the inferior vena cava and 17 (39%) had involvement of the renal vein at operation. Venacavography and magnetic resonance imaging correctly identified 9 of the 11 patients (82%) with inferior vena caval thrombus. When the results of both tests were combined, all 11 cases of vena caval extension were identified. Venacavography was slightly more sensitive (71%) in identifying the presence of renal vein thrombus than magnetic resonance imaging (65%) but these differences were not statistically significant. Magnetic resonance imaging better localized the thrombus within the renal vein. We conclude that venacavography and magnetic resonance imaging offer equal diagnostic accuracy in the identification of venous extension of renal cell carcinoma. The combination of both tests results in higher diagnostic yield than either test alone. Neither test by itself is reliable in the presence of a large, bulky adenopathic lesion that compresses the inferior vena cava.