Based on our experience, device implantation errors characterized by high risk of VTE. It is very important to assess tip position intraoperatively and have final X-ray shot before patient leave operating room. Because children usually are very active, physical activity may be a real reason of catheter tip migration (in jugular or brachiocephalic veins) with thrombosis development. Any case of device malfunction should be recognized as suspicious for catheter misplacement and immediately assessed by ultrasound, then by X-ray or CT. Device explantation and anticoagulant therapy is only acceptable strategy to eliminate VTE cause and prevent thrombosis progression. Venous access is very critical in pediatric oncology for treatment quality and disease prognosis, thus, avoiding of chemotherapy interrupting is a serious task for all team.