What are IVC filters?

• A. Umbrella-shaped devices that prevent emboli from migrating to the heart and lungs
• B. Stents placed in the vena cava
• C. Coils used to treat varices
• D. Pacemaker leads placed in the vena cava

Answer: (A)

IVC filters are umbrella‑shaped or cage‑like devices implanted in the inferior vena cava to catch thrombi that form in the legs and pelvis, preventing them from traveling to the heart and lungs and causing a pulmonary embolism. They act as a sieve, allowing normal blood flow but trapping emboli so they don’t reach the pulmonary circulation. They’re often placed via the femoral or internal jugular vein and can be either permanent or retrievable. They’re used when anticoagulation can’t be used or when PE recurs despite therapy. They’re not stents, coils for varices, or pacemaker leads—those have different purposes and placements.