Double Inferior Vena Cava With Mega Cava: A Case Report

We present the case of a 68-year-old male with a history of hypertension, prostate cancer, and glioblastoma, who presented for inferior vena cava (IVC) filter placement due to a deep venous thrombosis (DVT) with elevated thromboembolic risk and a contraindication to anticoagulation secondary to fall risk from ataxia. Pre-procedural imaging revealed a rare double IVC variant with a mega cava configuration above the confluence - a condition that can complicate vascular interventions and increase thromboembolic events. The anatomical variation made a single IVC filter infeasible due to size constraints and instead prompted the use of dual IVC filters, one in each IVC, to ensure protection against pulmonary embolism. A double IVC occurs when there is persistence of the bilateral supracardinal veins during embryogenesis. In cases of mega cava (diameter >28 mm), conventional IVC filters are ineffective. This case involved the placement of two filters to optimize protection against pulmonary embolism due to the large IVC diameter, with the option of a Bird's Nest filter as an alternative approach. Dual filters were chosen, as they effectively covered both venous channels while offering retrievability, compared to the Bird's Nest filter, which is permanent and may pose a higher risk of complications, including migration or IVC perforation. This case adds to the current knowledge base by demonstrating that dual IVC filter placement is an effective strategy for managing patients with a double IVC and mega cava when single filter placement is not possible. This case highlights the importance of recognizing and managing unique anatomical variations in IVC filter placement. Endovascular surgery requires a strategic approach, utilizing pre-procedural imaging to plan the next steps and optimize thromboembolic protection.