Filters that are implanted in the vein that carries deoxygenated blood to the heart is used as part of a treatment to prevent pulmonary embolisms, but complications associated with them have led to a series of lawsuits.

The device in question is the inferior vena cava filter, or IVC filter. This device is implanted in the inferior vena cava to block loose blood clots from migrating from the lower leg to the heart or lungs, potentially causing a pulmonary embolism.

The small basket-like device when working properly traps blood clots and holds them in place. IVC filters then allow natural anticoagulants in the blood to dissolve them over time.

IVC filters are considered an alternative treatment for patients who are at risk for pulmonary embolism, but for whatever reason are not able to take anticoagulant medication. However, use of IVC filters has not been without complications.

One study published in the journal Seminars in Interventional Radiology in June 2006 reviewed the many complications that can be associated with IVC filters. One of the more common errors in implantation that the researchers found was defective deployment of the filter’s legs — either the legs had been crossed or had not fully expanded into the vein.

The researchers found one case in which placement of an IVC filter led to a hematoma in the groin that compressed the patient’s femoral artery, restricting blood flow to the leg. Other filter placements also resulted in deep venous thrombosis at the access site.

Even when implantation has been correct and successful, other kinds of IVC filter complications can develop later. Researchers found reports of IVC filters migrating out of their proper position to elsewhere in the inferior vena cava, into the heart itself, or into the pulmonary outflow tract. In the latter two situations, removal of the filter generally requires surgery.

The researchers also note that while IVC filters reduce the risk of pulmonary embolism, they increase the risk of deep venous thrombosis, or DVT. They cite studies that found increases in rates of DVT in IVC filter recipients varying from 13 to 44 percent.

There were also reports of filters that fractured after implantation and others that punctured the vein’s wall or other nearby structures. The researchers noted that removal of temporary IVC filters comes at a risk of perforating the vein.

IVC Filter Lawsuits

With the rise in awareness of these IVC filter complications has come the development of a group of IVC filter lawsuits. In the federal court system, hundreds of these claims have been consolidated into two multidistrict litigations, or MDLs.

An MDL in Arizona is handling IVC filter lawsuits against manufacturer C.R. Bard Inc. about its Recovery and G2 IVC filters, while the other MDL in Indiana addresses IVC filter lawsuits against Cook Medical Inc.’s IVC filters.

Generally, the plaintiffs in these IVC filter lawsuits are patients who suffered from complications with IVC filter implantation. They typically allege that the respective manufacturers of these devices failed to properly warn patients and physicians about the dangers of IVC filter complications. Some claim that had they been properly informed about the risks, they would have chosen not to have an IVC filter implanted.