image: Wikipedia Inferior vena cava filters (IVCF) are placed to prevent deep venous thromboses (DVT) from traveling to the heart and lungs, causing pulmonary embolism (PE). IVC filters' rationale makes sense, but despite their wide use, the benefits and risks of IVCF remain unclear. With about 50,000 IVC filters placed annually in the U.S., that's a lot of unclarity. IVCF are standard care for patients with acute pulmonary embolism or proximal DVT who cannot receive anticoagulation because of bleeding risk. But IVCF are used more often as an additional preventive therapy along with anticoagulation in an attempt to further reduce PE risk. Is this good medicine?