Tumor infiltration of the vena cava in nephroblastoma.

Although operative treatment of Wilms' tumors has become more straightforward as a result of advances in preoperative treatment and precise diagnosis, vascular involvement by the tumor can cause serious problems at operation. These problems can be more easily managed if they have been identified pre-operatively and the level of the intravascular tumor thrombus has been defined. In this study we propose a classification of intravascular involvement of Wilms' tumors suggesting the clinical consequences and operative strategy. In our series of 84 patients we treated 7 (8.3%) with preoperatively diagnosed intracaval tumor thrombus using ultrasound as the most sensitive non-invasive diagnostic technique. The surgical therapy depends on the stage; stage III and stage IV should be operated in cooperation with the cardiovascular surgeon in deep hypothermic circular arrest.