Some patients report that inferior vena cava filter risks were greater than what they were led to expect by the manufacturer’s product information

An inferior vena cava filter, or IVC filter, is a small basket-like device designed to be placed inside the inferior vena cava, the large blood vessel that returns blood to the heart.

IVC filters are used to trap blood clots and prevent them from moving from the lower body to the heart and lungs, where they can cause a dangerous and potentially deadly pulmonary embolism.

These filters are suitable for use in patients who are at risk for pulmonary embolism but for one reason or another can’t take anticoagulant drugs.

Some inferior vena cava filters are designed to be left in place permanently. Others are intended to be removed as soon as the risk of blood clot injury has subsided.

Filters in the latter group are preferred for patients in whom the risk of pulmonary embolism is expected to eventually resolve – for example, victims of severe trauma, or surgery patients who may require prolonged immobilization.

Review Reports Inferior Vena Cava Filter Risks

A review published in the journal Seminars in Interventional Radiology in 2006 summarizes some of the more frequently reported complications associated with IVC filters.

These complications can occur during implantation or retrieval, or they can happen while the filter is in place.

Complications that arise during placement are generally less severe. Once the filter is in place, inferior vena cava filter risks may be more problematic. The review mentions that inferior vena cava filters can cause significant problems while in place. In some cases, these problems end in the patient’s death.

Reported inferior vena cava filter risks can include:

Migration: Filters have been known to move out of their proper place. They can end up elsewhere in the inferior vena cava, the heart itself, or the pulmonary outflow tract. Filters still inside the IVC may be removable by a simple procedure similar to that used to implant them, but those stuck inside the heart must be surgically removed.

Thrombosis: While filters are intended to protect the heart and lungs from blood clots, they are associated with an increased risk of forming such clots in the lower leg. One study reported a 40 percent higher incidence of deep venous thrombosis in patients who had no evidence of that condition prior to filter insertion.

Fracture: Some filters have reported to fracture while in place. This problem may sound worse than it is, as fractured filter struts generally aren’t problematic.

Perforation of the Vein Wall: If the filter punctures the wall of the inferior vena cava, it may protrude further and puncture the aorta, urethra, or duodenum. In at least one case, laceration of a lumbar blood vessel led to significant bleeding.

Pulmonary Embolism: Studies have found that the condition these filters are intended to prevent occurs at rates as high as 5 percent or more in patients implanted with IVC filters.

For filters designed to be retrieved, the retrieval procedure can present its own inferior vena cava filter risks. Retrievable filters are at risk for fracture during removal. Complications like filter repositioning may make removal more prolonged than expected, or they may even prevent removal entirely.

Whether or not the manufacturers of these filters adequately warned patients of the associated risks has been the subject of hundreds of products liability lawsuits. Plaintiffs in those cases argue that manufacturers like C.R. Bard and Cook Medical were aware of these risks yet failed to properly warn patients about them.