FDA Warns About Risk from Medical Filters

They are designed to save lives, but implantable filters that keep blood clots out of the lungs can become a health hazard if left inside the body too long, the U.S. Food and Drug Administration (FDA) warns.

In an online advisory to doctors and patients, the FDA claims it has received 921 reports about problems with inferior vena cava (IVC) filters since 2005. Some of those problems include a detachment and shifting of the IVC, the perforation of blood vessels and fractured filters, according to the FDA.

The filters, manufactured by Johnson & Johnson, C.R. Bard Inc., Angiotech Pharmaceuticals Inc. and Rex Medical L.P., are used in patients at risk of developing deadly blood clots known as pulmonary embolisms. Similar to a mesh umbrella (the FDA describes them as “small, cage-like devices), the filters are inserted into the inferior vena cava—the main vessel carrying blood from the lower body to the heart—to prevent clots from reaching the lungs.

Blood clots affect more than 200,000 Americans on an annual basis. Typically treated with blood-thinning drugs, clots also can be controlled with the use of IVCs, particularly in patients who cannot take blood-thinning drugs or those who develop clots despite medication. Doctors implant about 30,000 filters each year.

IVC usage has increased astronomically over the last 30 years. In 1979, surgeons implanted 2,000 IVC filters in patients; by 2007, that number had swelled to nearly 167,000, according to FDA data. Such explosive growth is expected to continue for the next two years, with the number of IVC filters implanted in 2012 estimated at 259,000.

Some IVCs are permanent, but many are used on a short-term basis and should be removed. In its Aug. 9 safety alert, the FDA recommends that doctors consider removing the filters once a patient’s risk of blood clots subside. “The FDA is concerned that these retrievable IVC filters, intended for short-term placement, are not always removed once a patient’s risk for pulmonary embolism subsides,” the agency noted in its alert. “FDA recommends that implanting physicians and clinicians responsible for the ongoing care of patients with retrievable IVC filters consider removing the filter as soon as protection from pulmonary embolism is no longer needed.”

The FDA has not recalled any filters. However, the agency will issue a final statement on the matter once it completes its analysis of data on filter problems. The final statement could range from another safety alert to a full-fledged device recall.