Inferior vena cava involvement in children with Wilms tumor.

OBJECTIVES: Retrospective review of children with WT thrombus involving the IVC.

METHODS: We reviewed the charts of 123 patients with WT diagnosed between January 2006 and December 2015. Patients with caval tumor thrombus were identified, demographic data, radiological images, extent of thrombus, chemo- and radiotherapy, surgical approach, pathology reports and outcomes were analyzed.

RESULTS: IVC involvement was identified in 11 patients (9%). Left-sided tumors were more common (55%). Sensitivity of CT scan in thrombus identification was 64%. Neoadjuvant chemotherapy was the primary mode of treatment with 19% reduction of primary tumor size, thrombus resolution in four and regression in six patients. No thrombus progression was observed. Delayed surgical treatment was either nephro-ureterectomy (nine patients) or partial nephrectomy in patients with bilateral WT (two patients). During surgery, thrombectomy and intimal stripping achieved local control in patients with persistent caval tumor. Cardiopulmonary bypass was not needed in patients with initial atrial involvement (five patients). Despite adherence and invasion of tumor thrombus to IVC wall, only one patient required segmental vein resection. All patients eventually achieved CR, none had local relapse. One patient had lung relapse treated to complete remission. The 3-year EFS is 85.7 ± 13.2% and the 3-year OS is 100%.

CONCLUSION: IVC tumor thrombus in patients with WT was managed successfully using preoperative chemotherapy followed by surgery with minimal aggressive approach. Luminal thrombus removal and intimal stripping supplanted by local radio boost when indicated seem to be adequate tools for local control with documented good overall outcomes.