Wilms Tumour with Intracaval thrombus in the UK Children's Cancer Study Group UKW3 trial

Background/Purpose To define the clinical characteristics and surgical management of intracaval involvement in patients enrolled in the UKW3 trial (1991-2001), which recommended elective preoperative chemotherapy for such cases. Methods Cases were identified from preoperative imaging and surgical trial forms. These asked specific questions about whether the surgeon suspected intracaval extension at diagnosis or found it at nephrectomy. For tumors with Wilms' histology, original case notes were examined. Results Of 842 patients registered in UKW3, 730 (87%) had Wilms' tumor. Among them, 59 (8.1%) had evidence of intracaval extension, either documented at diagnosis (53) or found unexpectedly at nephrectomy (6). Intracaval extension was also seen in tumors of other histology. The level of thrombus was intraatrial (10), suprahepatic (9), retrohepatic (8), infrahepatic (26), and unknown (6). The median age at diagnosis was 3.75 years compared to 2.97 years in patients without inferior vena cava thrombus (P < .0001). Fifty-two of 59 received preoperative chemotherapy. Thirty-one (52%) needed cavotomy, and 3 (30%) with intraatrial extension required cardiopulmonary bypass. The commonest operative complication was significant hemorrhage and resulted in mortality in 3 cases. Conclusions Preoperative chemotherapy is a useful adjunct to shrink the tumor and thrombus. This reduces the requirement for cavotomy and cardiopulmonary bypass. Intraoperative hemorrhage remains a significant cause of operative morbidity and mortality.