When anticoagulants do not work for a patient with blood clot risks, physicians often turn to a device known as an IVC filter.

However, there are certain blood clot filter risks associated with the devices.

An IVC filter, or an inferior vena cava filter, is a small device that is inserted into one of the main veins of the body to collect any blood clots that may travel from the lower extremities of the body to the heart or lungs.

At times, blood clots form in the lower body, sometimes due to hip or knee replacement surgery. If these blood clots travel, it can result in a pulmonary embolism or heart attack.

When a blood clot travels to the lungs specifically, this condition is called a pulmonary embolism.

The Food and Drug Administration approved the device in 1979 and by 2012, surgeons had inserted approximately 260,000 in patients. Two major medical device companies manufacture blood clot filters: C.R. Bard and Cook Medical.

However, blood clot filter risks are a real concern for both patients and the medical community.

Blood Clot Filter Risks

The most common blood clot filter risks fall into three categories: procedural complications, retrieval complications and delayed complications.

Procedural complications happen when the blood clot filter is inserted. These include defective filter deployment, incorrect placement and access site bleeding, bruising and blood vessel puncture.

Retrieval complications occur when doctors remove temporary filters. These may include blood vessel perforation, scars in the vein which can prevent removal, difficulty in retrieval and large existing clots which prevent removal.

Another category of blood clot filter risks is delayed complications. These complications are the most serious and occur with the device is already in the body.

These include migration to other parts of the vein or to the heart or other organs, deep vein thrombosis (blood clots in the legs), filter fracture or breakage, infection, perforated organs, blockage and the embolization of the filter itself.

By 2010, the FDA had reported potential blood clot filter risks in a safety alert regarding retrievable IVC filters.

Most of the adverse event reports, about 35%, cited device migration. Embolization, or when the components of the device detach, was the second most reported adverse event.

Retrievable filters are only intended to be in the body short-term. However, many devices are left in the body long after the blood clot risks subside.

In 2014, the FDA updated the previous safety alert and recommended that retrievable devices be removed between the 29th day and the 54th day after insertion.

However a 2013 study in the Journal of the American Medical Association looked at failure rates of IVC filters. Out of 679 removable filters, doctors only removed 58.