RESUMO
INTRODUCTION: Venous thrombotic events (VTE) are becoming more and more common in children, particularly in the hospital setting. To date, 1 in 200 children admitted to tertiary pediatric hospitals are now being recognized to develop VTE. Amongst those patients with an identified thrombotic occlusion, pediatric patients diagnosed with renal tumors have long been recognized, but their ideal management in the instances of vascular invasion remains controversial. AIM: We describe the clinical behavior of patients diagnosed with renal tumors and extra renal vascular involvement at The Hospital for Sick Children in Toronto, Canada. MATERIALS AND METHODS: A retrospective analysis was conducted in patients diagnosed from 1990 to 2012. Data collected included: age, gender, symptoms at presentation, staging, pathology report, radiological evidence of intravascular thrombus [i.e. renal veins (RV), inferior vena cava (IVC) and right atrium (RA)], intraoperative findings, therapeutic protocol implemented and anticoagulation; for outcomes, tumor and/or thrombus recurrence, thromboembolic phenomena [i.e. pulmonary embolism (PE)] and survival. RESULTS: Of 299 patients with renal tumors identified, 292 were included: Wilms (219), Renal Cell Carcinoma (RCC, 29), Clear Cell Sarcoma of the Kidney (CCSK, 12), others (32). The median age of the group was 4.53years (4days - 18 years). Extra renal vascular disease was identified in 29 patients, with a median age 7.05years (0.6-16 years; p=0.03), including Wilms tumors (22/219, 10%), RCC (2/29, 7%), CCSK (1/12, 8.3%) and others (4/32, 12.5%; p=0.01). Vascular involvement comprised exclusive evidence of RV disease (7), IVC disease (19; 15 infra-hepatic), RA disease (3) and PE (5).Treatment escalation because of vascular disease included neo-adjuvant chemotherapy (12; Wilms [11], RCC [1]), intraoperative cavectomy/ thrombectomy (1; Wilms), and cavotomies (11 Wilms [7], RCC [1], CCSK [1], PNET [1], sarcoma [1]). Four patients were placed under cardiopulmonary bypass. Anticoagulation was administered in 9/29 patients for their tumor-related thrombus, and one had a minor bleeding complications (oozing from the central venous line insertion site). CONCLUSIONS: Renal tumors with vascular invasion are a rare and challenging entity. Treatment included mostly cancer-related therapies and the role of vascular surgical approaches and/or systemic anticoagulation remains to be clarified.