During Inferior Vena Cava (IVC) filter placement, a filtering device is placed within the IVC, a large vein in the abdomen that returns blood from the lower half of the body to the heart. Blood clots in the veins of the legs and pelvis can occasionally travel to the lungs where they may cause a pulmonary embolism or blockage. IVC filters help reduce the risk of pulmonary embolism by trapping large clots and preventing them from reaching the heart and lungs. They are used in patients who don't respond to or cannot be given conventional medical therapy such as blood thinners.
A special device called a snare is inserted into the jugular vein, the large vein in the neck. Most removable IVC filters have a small hook at one end. Using fluoroscopy (X-ray guidance) the snare is used to latch onto the small hook, and once attached, to withdraw the filter.