Ricerc@Sapienza

Background: Wilms tumor (WT) is the commonest renal cancer during childhood. Intravascular extension is a well-recognized phenomenon in WT patients, usually involving renal vein and inferior vena cava (IVC), sometimes with invasion up to the right atrium. Most intracaval and intraatrial thrombi show a good response to preoperative chemotherapy. However, treatment of persistent intravascular extension represents a surgical challenge and may be associated with significant morbidity. Notably, there are no formal practice guidelines to define the optimal surgical treatment of IVC involvement, namely whether or not IVC resection allows better tumor clearance and whether or not vascular reconstruction after IVC resection is needed. Therefore, in the absence of representative studies, the aim of present study project is to determine the clinical profile of WT patients undergoing circumferential resection of the IVC with or without reconstuction, with special emphasis on their oncologic outcomes and procedure-related morbidity.
Methods: Multicenter, longitudinal observational study on WT patients receiving cavectomy as part of their surgical treatment for IVC involvement. Data collected will include patient demographics, stage of disease, laterality of renal primary, level of IVC extension, indications for cavectomy, histopathology, treatment received, morbidity and mortality. A special clinic follow-up will be arranged to obtain additional data and provide long-term outcomes into adulthood.
Hypothesis: In WT patients with IVC involvement and complete luminal occlusion, cavectomy without reconstruction is well tolerated because these patients have well-developed collaterals secondary to pre-existing IVC occlusion. IVC prosthetic replacement is a timeconsuming and technically demanding procedure that is not without complications.
The study will provide overall and relative estimates of the lifetime risk of developing lower extremity deep vein thrombosis in these patients.