Deep vein thrombosis is a complication of using an IVC filter. As a medical complication of IVC filters, deep vein thrombosis is disturbingly severe and common. Worse, deep vein thrombosis can happen even if the IVC filter is working as it was designed to work. As a result, numerous IVC filter lawsuits have been filed by victims who have developed life-threatening and debilitating deep vein thrombosis because of their IVC filter.
- 1. What is deep vein thrombosis?
- 2. How can IVC filters cause deep vein thrombosis?
- 3. IVC filter lawsuits filed for causing deep vein thrombosis
1. What is deep vein thrombosis?
Deep vein thrombosis is a medical condition caused by a blood clot that blocks some or all of the blood flow in a vein that is far away from the skin.
Thrombosis is the medical term for a blood vessel – either a vein or an artery – that is blocked by a blood clot, at least to some extent. When a vein is blocked by a clot, the flow of blood from the affected area back to the heart and lungs is drastically diminished. Thrombosis can lead to the following symptoms:
- Redness and warmth in the affected area,
- Pain, and
Deep veins are the veins that located far beneath a patient's skin. They are contrasted with superficial veins, which are close to the surface and can occasionally be seen through the skin. Deep veins carry the vast majority of the blood from a person's extremities back to their heart and lungs.
When these deep veins get blocked or partially blocked by a blood clot, the medical condition is called deep vein thrombosis. Deep vein thrombosis causes some severe medical complications, including:
- Post-thrombotic syndrome, where so little blood returns to the heart that it can cause pain, paresthesia, and leg ulcers,
- Pulmonary embolism, a potentially fatal condition where a blood clot breaks away and travels from the location of the thrombosis to the lungs and blocks an artery there,
- Cardiac Tamponade,
- Decreased blood circulation, and
- Pain and decreased mobility from swelling in the affected area.
2. How can IVC filters cause deep vein thrombosis?
While IVC filters are designed to prevent the very pulmonary embolisms that deep vein thrombosis can cause, they actually increase the risk of developing deep vein thrombosis over the long term. One medical study suggested that the increased risk for deep vein thrombosis came from the IVC filter, itself.1
2.1 How IVC filters work
IVC filters work by catching blood clots as they travel through the inferior vena cava vein. This vein is the largest in the human body, and brings blood from the lower extremities to the heart and lungs.
Surgeons implant IVC filters by making a small incision in the patient's neck or groin, inserting the IVC filter, and using a catheter to guide the device into the inferior vena cava in the patient's abdomen. There, the IVC filter, which is shaped like the frame of an umbrella, is opened so its struts catch onto the interior of the vein's walls.
Once positioned in the inferior vena cava, an IVC filter catches blood clots on their way up the vein. By preventing blood clots from reaching the heart and lungs, an IVC filter prevents them from causing a pulmonary embolism.
2.2 Studies connect IVC filters to deep vein thrombosis
However, studies have found that IVC filters significantly increase the risks of developing deep vein thrombosis over the long term.
According to one study, deep vein thrombosis got increasingly more common in patients the longer an IVC filter was left inside their inferior vena cava vein2:
- After 1 year: 8.5%,
- After 2 years: 20.8%, and
- After 8 years: 35.7%.
One study suggested that the accumulation of small blood clots in the IVC filter slowly stagnated the flow of blood through the inferior vena cava vein, which in turn slowed the flow of blood into the inferior vena cava from deeper veins, which in turn contributed to blood clots forming in the deep veins, or deep vein thrombosis.3
3. IVC filter lawsuits filed for causing deep vein thrombosis
Because IVC filters are designed to trap blood clots, and because studies have suggested that trapped blood clots in the inferior vena cava can lead to deep vein thrombosis, lawsuits have been filed against the makers of IVC filters for the injuries that they have caused.
These lawsuits claim that IVC manufacturers could have designed safer devices, but did not. That failure amounted to a defect that caused people to suffer serious injuries that deserve to be compensated.
The lawsuits also claim that IVC manufacturers failed to warn doctors and patients about the increased risk for deep vein thrombosis that their IVC filters caused. Without that warning, neither doctors nor patients could make fully informed decisions about their health.
White RH, Zhou H, Kim J, Romano PS, “A population-based study of the effectiveness of inferior vena cava filter use among patients with venous thromboembolism,” Archives of Internal Medicine 160(13):2033-41 (July 10, 2000).
PRECIP Study Group, “Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prevention du Risque d'Embolie Pulmonaire par Interruption Cave) randomized study,” Circulation 112(3):416-22 (July 19, 2005).
Andreoli JM, Thornburg BG, Hickey RM, “Inferior Vena Cava Filter–Related Thrombus/Deep Vein Thrombosis: Data and Management,” Seminars in Interventional Radiology 33(2):101-4 (June 2016).