An IVC filter (inferior vena cava filter) is a medical device used to stop blood clots from traveling through the body. They are small, cage-like devices that are inserted into the inferior vena cava, or the main vein that carries deoxygenated blood from the lower half of the body to the right atrium of the heart. 

These inferior vena cava filters capture blood clots and prevent them from moving through the heart or to the lungs, which could cause serious problems like a pulmonary embolism (PE).

Blood clots trapped in the IVC filter stay in the filter until they are dissolved by the body.

What do IVC filters protect against?

Blood clots that form in the legs, also called deep vein thrombosis, can travel up the inferior vena cava where they can become lodged in the lungs. When a blood clot blocks the blood vessels in the lungs, this is called pulmonary embolism. Pulmonary embolism can be extremely dangerous and life-threatening, so treating and preventing these occurrences is often a priority for doctors.

In many cases, deep vein thrombosis and related pulmonary embolism are treated through blood-thinning drugs. However, not all patients are able to take these medications. In these patients, or in patients who are at risk for recurring clots, an IVC filter may be the best treatment option.

IVC filters can help prevent a number of conditions linked to blood clots. The FDA has approved them for use in patients with the following:

• pulmonary thromboembolism when anticoagulant therapy cannot be used, or if the anticoagulant therapy cannot be used
• emergency treatment after massive pulmonary embolism if conventional therapy would be ineffective
• chronic, recurrent pulmonary embolism if anticoagulant use has failed or cannot be used

How Are IVC Filters Placed?

IVC filters are typically placed through a simple procedure performed by an interventional radiologist. Using image-guided techniques, the collapsed IVC filter will be guided into the vena cava by accessing a vein in the groin or neck. Once in place, the IVC filter is “unfurled” and positioned. The Memorial Sloan Kettering Cancer Center notes that the procedure should only take around 30 minutes.

Are IVC Filters Safe?

As with any medical device, the use of an IVC filter can pose a danger. Unfortunately, the FDA has received a significant number of reports that relate to problems with IVC filters.

Some IVC filters are permanent, but others are meant to be temporary and removable. Less than half of all IVC filters that are implanted are removed, and according to some estimates, the number of retrieved filters may be as low as 8.5 percent.

This low retrieval rate may be alarming for some patients, due to the potential health hazards that may arise from having an IVC filter remain in the body for years or decades. According to the FDA, at least 900 complaints were lodged regarding IVC filter complications between 2005 and 2010. The risk of perforation, migration, or other complications may increase with the amount of time the filter remains in the body.

Some patients claim that large companies who make IVC filters were aware that the devices could pose a danger, but marketed them as safe nonetheless.

Some researchers also argue that IVC filters are overused. A 2016 study published in the Cardiovascular Diagnosis and Therapy journal notes that the complications associated with IVC filters must be considered when choosing to use the devices. The researchers also noted that it is difficult to determine which patients would be appropriate for these devices and which patients are placed at unnecessary risks.

“Although IVC filters have become an increasingly accepted as a low morbidity method of preventing PE there is little prospective data to guide physicians on which patients would benefit most,” the researchers concluded.

How can IVC filters fail?

IVC filters can fail in a number of ways. They can fail by breaking into pieces which can cause them to perforate the internal organs, by moving from their intended location and blocking flow to the heart, among a number of problems. These issues can be serious, and can even be fatal.

According to one patient who received her IVC filter in 1992 after a blood clot formed in her lower leg, no one talked to her about the potential side effects of having a permanent device implanted in her body.

After a decade of walking around with the device inside of her, she began to experience abdominal issues and symptoms of a broken IVC filter. An MRI scan from her doctor showed that the IVC filter had perforated her small intestine, and was only millimeters away from perforating her aorta. Although at the time that the device had been implanted, it was necessary to make sure that her blood clot did not cause her to experience a potentially life-threatening pulmonary embolism, she claims that the device meant to save her life could have killed her.

She and other victims of IVC filter complications have accused medical device manufacturers of knowing about these potential risks and failing to warn patients.

What are the symptoms of a broken IVC filter?

Some patients who have had an IVC filter break while in their body may have no complications. Others, however, may have painful symptoms of a broken IVC filter.

When the IVC filter fractures and a piece migrates, patients can develop pain in their chest or back. In some cases, serious conditions like the following can develop:

• IVC thrombosis
• Deep vein thrombosis
• Access site thrombosis
• Filter migration
• Organ or inferior vena cava fracture

How do doctors deal with symptoms of a broken IVC filter?

In some cases, doctors may have to remove a defective IVC filter. Though some filters are designed to be removable, some filters that are intended to be permanent may need to be removed if they are defective or fractured. This removal procedure can be challenging and dangerous in itself.

The FDA has noted that most IVC filter problems are connected to long-term use of the device, and work best as a temporary solution to the problem of blood clots. The FDA advises that once a patient’s risk for pulmonary embolism has passed, an IVC filter should be removed between 29 and 54 days after it was implanted.