Since the FDA issued a safety alert regarding IVC filters in 2010, there has been a steady decline in the number of physicians using the device. However, even seven years after the advisory was issued, the rate of IVC filter implantation in the United States is still as much as 25 times greater than in the European Union.

The inferior vena cava (IVC) filter is a small, cage-like device resembling a cellar spider, which is inserted into the major artery leading from the lower extremities to the heart. This device has been used in patients who are at risk for deep-vein thrombosis (DVT), in which blood clots can break free and travel to the heart and/or lungs, causing pulmonary embolism.

The filters are used in patients who for various reasons are unable to take anticoagulant medications. The U.S. Food and Drug Administration published a safety advisory in 2010 after a review of over 900 adverse events, in which IVC filters were reported to have fractured and/or broken loose, causing severe internal injuries. Although designed to remain in a patient’s body for no more than three to six months, IVC filters often remain implanted for years – and are exceptionally difficult to remove.

A recent study published this month in the Journal of the American Medical Association examined the rate at which IVC filters were being used and what effect the FDA advisory had had on usage by surgeons. According to that study, approximately 1.13 million patients received an IVC filter over a ten-year period between 2005 and 2015. The research team found that after the FDA issued its advisory in August of 2010, the use of IVC filters decreased by 29%. The lead author, Dr. Riyaz Bashir, wrote, “The significant decrease in IVC filter implantations after the FDA communication reflects that such communications are a very powerful means of affecting contemporary practice patterns around the country.”

However, he also noted that rates of IVC implantation in the U.S. remains high compared with major European countries. Dr. Bashir points out that “hospitals across this country collectively are spending close to a billion dollars on these devices every year without a known significant benefit.” He adds that “with current level of evidence we believe that the appropriate implantation rate in the U.S. should be similar to, or lower than, the rate observed in Europe.”

The Bashir team’s findings confirm those of an earlier study indicating that the FDA safety alert indeed had an impact on the rate at which surgeons were employing IVC filters. What is not understood is why those rates remain so much higher in the U.S. than in Europe. In a JAMA editorial, Dr. Rita Redberg points out the lack of evidence on the efficacy of IVC filters. Other studies have showed the devices to be not only useless, but dangerous as well. Of IVC filters, Dr. Redberg writes “There should be a moratorium on their use unless or until there are data showing efficacy greater than risk.”