Retrievable IVC filters should be removed “between 29 and 54 days after implantation,” according to the US Food & Drug Administration. Obviously, these devices are a short-term solution, ideally suitable only when patients are at an extremely high risk of pulmonary embolism. But most of the time, that’s not how the “umbrella filters” are used in real clinical settings.
Despite Guidelines, Doctors Are Leaving IVC Filters In
It’s not uncommon to hear about patients who have been living with supposedly retrievable inferior vena cava filters for years. Which could be a serious problem, since IVC filters often break, causing serious harm, and the risk of fracture increases the longer they stay in.
Some IVC filters are actually designed to be permanent implants. That’s how the concept first began, in 1967, when a surgeon at the University of Miami developed the first inferior vena cava filter. Dr. Kazi Mobin-Uddin’s invention, subsequently dubbed the “Mobin-Uddin umbrella” was eventually released for clinical use in 1970. But people were already toying with the idea of an IVC filter that could be removed back then.
Throughout the 1970s, several surgeons in New York were experimenting with a “removable intracaval filter,” as old papers published in the journal Surgery attest. Retrievable IVC filters would only hit the market, though, in 2003. Over the next 7 years, hundreds of thousands of patients received filters, as the device’s approved indications expanded. In the meantime, patients were experiencing severe side effects. Between 2005 and 2010, the FDA received a total of 921 adverse event reports of IVC filters moving out of position, breaking and traveling to the heart or lungs. The agency explicitly linked these complications to “retrievable” IVC filters that were being allowed to stay in patients.
In fact, we only know how long IVC filters can stay in because so many people were harmed by them. The FDA only began studying the relationship between filter failure and “indwelling” times after receiving all of those reports – many of which involved serious patient harm. In one of the papers commissioned by the agency, published in the February 2012 edition of Endovascular Today, which was devoted entirely to IVC filters, researchers reported that “the majority of optional filters are not retrieved.”
Majority Of Filters “Left In Place Indefinitely”
In that same journal, surgeons at the University of Utah reported on a “disturbing trend”: the more temporary IVC filters doctors used, the more “dismal filter retrieval rates” became.
Obviously, retrievable IVC filters weren’t designed to be permanent. But numerous studies have shown that they often become permanent, because surgeons just don’t take them out.
This is true even in patients who receive filters during acute trauma situations. Traumatic injuries increase the risk for pulmonary embolism (PE), so many surgeons have begun using IVC filters to reduce that risk after an accident. They don’t, however, seem to remove the filters after a patient’s risk of PE has gone down. In one study of 446 patients who received retrievable IVC filters after traumatic accidents, only 22% of the filters were removed afterwards.