Permanent Versus Retrievable IVC Filters
For patients who have suffered a traumatic injury or who are undergoing voluntary or emergency surgery, inferior vena cava (IVC) filters can help trap blood clots that may break free from the lower extremities, and prevent them from traveling to the heart and lungs, where they can cause serious complications. The filters are implanted in the inferior vena cava – the largest vein in the body – and feature a cage-like construction that, while designed to capture blood clots, allows deoxygenated blood to continue to flow around the device and return to the right atrium of the heart. Blood clot filters are intended to reduce the risk of stroke, pulmonary embolism, and other serious medical conditions, but it’s also important to be aware of their risks.
There are two types of inferior vena cava filters: permanent and retrievable. Both filters are implanted using a catheter that is inserted through the skin in a large vein in the groin or neck and then advanced to the inferior vena cava in the abdomen, but the main difference between the two is that retrievable filters are designed for short-term protection, and are meant to be removed once the risk of pulmonary embolism has subsided. The most dangerous complications stemming from retrievable IVC filters occur when the devices are left in place for long periods of time, even after protection from pulmonary embolism is no longer needed.
Common IVC Filter Uses
Although anticoagulant therapy is typically the first line of defense for blood clots, deep vein thrombosis (DVT) and pulmonary embolism, IVC filters may be a more appropriate treatment option for patients who have experienced recurrent DVTs while taking blood thinners, or for those who are unable to tolerate anticoagulant medications due to an adverse reaction, trauma, bleeding or recent surgery. Because of concerns over the long-term complications of permanent IVC filters, medical device makers began developing temporary filters, which are very similar in appearance to permanent filters, but which are designed to be removed once the risk of pulmonary embolism has subsided.
Potential Side Effects of IVC Filters
Despite their supposed improved safety profile over permanent filters, research has shown that removable IVC filters carry their own risk of serious side effects, including device migration, filter fracture, perforation of the inferior vena cava, and embolization of the device to the heart and lungs. In light of the potential for retrievable blood clot filters to cause severe and potentially life-threatening complications in users, the U.S. Food and Drug Administration (FDA) issued a safety communication in 2010, highlighting more than 900 adverse event reports submitted to the agency in connection with removable IVC filters during the previous five years. The FDA updated its safety alert in 2014, recommending that temporary IVC filters be removed within one to two months after being implanted, to reduce the risk of device complications.
A number of studies have confirmed the FDA’s blood clot filter warnings, and one study published in the Journal of the American Medical Association in 2013 analyzed the failure rate of temporary IVC filters in 978 patients, indicating that when the filters remained in place longer than medically necessary, 18.3% of retrieval attempts failed and 7.8% of patients experienced venous thrombotic events, including 25 pulmonary emboli, all with the IVC filter in place. Some of the temporary IVC filters that have shown a potential to cause serious complications in users include C.R. Bard’s Recovery, G2, and G2 Express filters, which one study linked to a combined 12% rate of filter fracture side effects, and Cook Medical’s Gunther Tulip and Celect filters, which research has shown may be prone to migration and perforation complications.
IVC Filter Adverse Event Reports
IVC filter devices have been implicated in a growing number of reports of injuries and fatalities in recent years, and many patients who have suffered serious complications after being implanted with a blood clot filter are now filing lawsuits against the medical device makers, alleging that the companies intentionally withheld information about IVC filter side effects from consumers, medical professionals and the FDA, which is not only deceitful, but illegal. For patients presented with IVC filter treatment as a means of reducing their risk of blood clots or pulmonary embolism, it is extremely important to understand the different types of filters currently on the market and what risks they may pose for users.