The Inferior Vena Cava is a large vein that drains blood from the lower half of the body back to the heart. Blood clots (thromboses) sometimes form in the veins of the legs and pelvis, and are known as deep vein thrombosis (DVT). The clot can sometimes break free and travel through the IVC and heart into the blood supply to the lungs and make you very sick. This is called pulmonary embolism (PE), which can be fatal.
An IVC filter is a small metal device placed into the IVC which prevents a large pulmonary embolism by trapping a clot before it reaches the lungs.
The usual treatment for deep vein thrombosis and pulmonary embolism is drug treatment to thin the blood with medication such as Warfarin. In a few patients, Warfarin does not prevent further pulmonary embolisms and in others, thinning the blood is too risky, for example prior to major surgery. When this happens, patients are considered for treatment by inserting an IVC filter.
Very occasionally, a patient is advised to have an IVC filter inserted even though they do not have a deep vein thrombosis or pulmonary embolism at that time.