[Ultrasound diagnosis of venous tumor thrombi in kidney cancer. A prospective study].

In a controlled prospective study 65 patients with renal tumors were evaluated by sonography prior to surgery in order to detect venous tumor extension. Tumor thrombi in the inferior vena cava (IVC) occurred in 12.3% and in the main renal vein (RV) in 16.9% of the patients. It was possible to visualize the entire retrohepatic IVC by ultrasound in 62%, as well as the RV of the tumor-bearing kidney along its length or in the proximity of the IVC in 85% of the cases. Among the assessable caval sonograms (60 of 65), endoluminal tumor thrombin were recognized in all 8 cases (accuracy 100%; sensitivity and specificity 100%). Among the assessable sonograms of the RV (55 of 65), venous tumor extension was identified in 10 of 11 cases (accuracy 98%, sensitivity 91%; specificity 100%). Compared with the results of transfemoral cavography, sonography apparently provides more information on endoluminal venous tumor extension.