Some blood clot filters, also known as IVC filters, may not be safe if the devices are manufactured or designed defectively.

What are Blood Clot Filters?

Blood clot filters, also known as IVC filters, are devices that are placed in the inferior vena cava (IVC) vein to prevent blood clots from reaching the lungs.

In the deep veins of the legs, blood is prone to clotting in a phenomenon known as deep vein thrombosis (DVT). Some people are more prone to DVT while others may develop the clotting phenomenon after being immobile for a long time, such as during a long plane ride.

These resulting clots then come up the body into the torso through the IVC. If the clots reach the lungs, they can block the delicate blood vessels responsible for lung functions. These blockages, called pulmonary embolisms (PE), can be life threatening if left untreated.

IVC blood clot filters are placed within the inferior vena cava, a large vein in the abdomen, to prevent pulmonary embolisms by breaking up the clots with branching wire formations before the clots reach the lungs.

These devices are made up of many spidery legs that extend and trap blood clots. However, over time, these legs may degrade and splinter off. If the broken pieces of the filter travel through the body, they may cause perforations or other damage.

Why Use an IVC Filter?

Typically, an IVC filter will only be recommended for patients who are extremely prone to pulmonary embolism formation and/or who do not respond well to or cannot take anti-coagulant (blood thinning) drugs like warfarin.

These filters are placed through a simple procedure during which an interventional radiologist uses imaging technology to visualize the filter’s placement. The IVC is accessed through the veins in the neck or groin and the filter carefully positioned in the desired place. The procedure is fairly simple and may only take 30 minutes.

Some IVC filters are designed to be permanent fixtures in the body and will never be removed. Other filters are designed to be removable with a prominent loop on one end.

However, in many cases, even the blood clot filters meant to be removable are left in the body for much longer than necessary. The length of time that these devices are left in the body may correlate with the likelihood of experiencing IVC filter complications.

Are Blood Clot Filters Safe?

Although blood clot filters have been approved by the U.S. Food and Drug Administration (FDA) as safe, some consumers and scientists claim they are the opposite.

Patients have experienced their filters breaking, migrating, and even perforating blood vessels and other vital parts of the body. Many of these patients have taken legal action against filter manufacturers, arguing that the IVC filters were designed defectively. In some cases, these filters have been recalled due to complications.

A 2018 study suggested that IVC filters are not worth the risks they may pose. The study, lead by a cardiologist from Temple University and printed in the journal JACC Cardiovascular Interventions, suggests that IVC filters do not play a role in helping patients leave the hospital due to clotting situations.

The study examined the outcomes of over 7,000 patients who had an IVC filter placed through a catheter procedure. Those who had a filter implanted in their vena cava vein were reportedly not more likely to survive their visit to the hospital and were instead more likely to suffer a hematoma due to partially clotted blood. These same patients were reportedly also held in hospitals longer, leading to larger medical bills.

“If somebody is able to take blood-thinning medicine, there is no reason to put a filter in,” said senior author Riyaz Bashir, a professor at Temple University’s Katz School of Medicine and Director of Vascular and Endovascular Medicine at Temple University Hospital.

Although some patients are afraid of the potential risks of leaving their IVC filter in their body, removing the devices may not always be easy or even possible.

NBC News reported on one patient who had an IVC filter implanted in 2010 says that he asked his doctor to check on the filter a few years later. He claims that when his doctor checked the location of the filter, he was surprised to see that it had traveled from its original location. The filter had gotten close to the patient’s heart, putting him at risk of a potentially life-threatening perforation. However, two different surgeons refused to attempt to remove the filter, due to the risks.

When the patient was finally able to have the filter removed, the surgeon who performed the surgery found that several of the filter’s legs had already detached and traveled to the patient’s lungs. An additional two damaged legs separated during surgery, and almost perforated his heart.

Dangers like this have led to several IVC filter recalls. If you or someone you love has been injured by an IVC filter, a specialized lawyer can help decide if you should pursue a lawsuit against the manufacturer.