Medical devices are designed with patient safety as a key priority. When doctors implant a device into a patient’s body, it is in an effort to do good, not harm. But despite approval from the Food and Drug Administration (FDA), some medical devices are found to do more harm than good after they are brought to the market and used in thousands, if not millions, of patients.
IVC filters are one example of a medical device that may do more harm than good in certain patients. Retrievable IVC filters are designed to provide protection from blood clots for a short amount of time. Surgeons are supposed to remove the filters once that time has elapsed. But studies and warnings from the FDA show that surgeons are not always removing the retrievable IVC filters from patients after their risk for blood clots has subsided, and these filters were not designed to remain in the body for long. Essentially, these tiny filters, which are meant to save lives, can actually put them at risk.
Retrievable IVC filters that are not retrieved can cause serious, life-threatening risks and complications. Essentially, IVC filters can become ticking time bombs — and it’s only a matter of time before complications from an irretrievable filter could arise.
Inferior vena cava filters, or IVC filters, are small, cage-like devices made of metal and are used in patients who are at risk for blood clots, especially those who cannot use traditional blood thinners.
IVC filters are used to catch blood clots before they reach the heart or lungs. These blood clots, called deep vein thrombosis (DVT), typically form in the inferior vena cava, the large vein that carries blood from the lower portion of the body back to the heart. These clots are dangerous and can cause heart attacks, strokes, and a condition called pulmonary embolism (PE) if they break off and travel to the heart or lungs.
IVC filters are intended to reduce the risk of these clot-related injuries, however, their use has come under scrutiny in the past several years because they may cause more harm than good in many patients.
This is especially true for retrievable IVC filters, the newest types of filters to hit the market. Retrievable IVC filters are designed to reduce a person’s risk for blood clots for a short amount of time, typically for less than a year. Once the person’s risk for blood clots has subsided, the IVC filter should be removed by a surgeon. This is not the case for the majority of IVC filter patients.
Retrievable IVC filters that are left in place for too long can cause serious problems of their own. The device may break apart in the patient’s body and travel to the heart or lungs causing heart attack or pulmonary embolism — the same medical emergencies the filter is intended to prevent. The devices may also puncture the lining of the inferior vena cava or break through the vein entirely and travel to other parts of the body.
There are other risks associated with leaving a retrievable filter in place for too long, and many patients do not realize they have one of these filters in place. In some cases, patients don’t experience symptoms from a fractured or migrated device until it’s too late.
IVC filters have been around for decades, but the original devices were designed to be permanent implants. Newer filters that came on the market in the early 2000s, on the other hand, were designed to be removed after a short period of time. Once a person’s risk for blood clots subsided, these retrievable IVC filters are supposed to be just that, retrieved.
Since the FDA approved retrievable filters less than 20 years ago, their use has grown dramatically. Doctors implanted about 167,000 filters in 2007 and it was estimated that nearly 260,000 filters would be used in 2012. Compare those numbers to just 2,000 filters implanted in 1979, when traditional filters were the only design on the market.
Doctors use IVC filters, both retrievable and traditional filters, in patients who are at-risk for blood clots. Doctors may choose to use an IVC filter in:
Patients who may be at a short-term risk for blood clots, such as those who suffered severe trauma or are undergoing surgery, may have a retrievable filter implanted to temporarily reduce their risk. Retrievable filters should be removed after a patient’s risk subsides, and were not designed to stay in the body for a long time.
Most retrievable IVC filters should be removed within a few months of implantation, but many patients live their lives for years with a retrievable filter still implanted. The longer a retrievable filter remains in place, the harder it is to remove and the riskier it is for patients.
The use of retrievable IVC filters has come under scrutiny in recent years due to the number of complications these filters can cause. Studies have shown that the use of IVC filters in trauma patients, for instance, can do more harm than good.
A JAMA Surgery study published in January 2017 showed IVC filters did not provide any additional lifesaving benefits to trauma patients and may actually be more risky for those patients because removal rates were so low. The single-center study looked at the mortality rates of trauma patients at risk for blood clots and found using IVC filters did not decrease their risk for death or other complications.
Another study, published in JAMA Surgery in August 2017, called the use of IVC filters in trauma patients “controversial” and a study published one month later said there is “growing concern for overuse of IVC filters, with a relatively low rate of retrieval.”
IVC filters are designed to save people from life-threatening injuries, but the filters can cause a number of serious complications on their own, as evidenced by numerous studies.
Side effects and complications associated with IVC filters include:
Long-term risks of IVC filters include deep vein thrombosis and blockage of the IVC, called occlusion.
As the potential risks of IVC filters became apparent, the FDA got involved, issuing safety communications to the public and conducting analyses of the adverse event reports it received from doctors and patients across the country.
The FDA first took action in August 2010 when it issued a safety communication to physicians and the public. The FDA said it had received a number of adverse event reports regarding the filters and worried retrievable filters were being left in the body too long.
From 2005 to 2010, the FDA received 921 adverse event reports relating to different IVC filter brands. The reports indicated the filters could cause serious complications in patients including:
Some of these complications led to other serious injuries in patients.
The FDA advised physicians to remove retrievable filters as soon as a person’s risk for pulmonary embolism had subsided because the longer a filter remained in place, the harder it would be to remove it.
In May 2014, the FDA issued an updated safety warning, advising doctors of the ideal window for safe filter retrieval. Based on its own analysis, the FDA said filters should be removed between 29 and 54 days after the device had been implanted, as long a patient’s risk for PE had subsided.
The FDA didn’t stop at issuing safety communications about the risks of IVC filters. The federal agency required manufacturers of retrievable IVC filters on the market at the time to participate in clinical trials to further assess the safety of the filters.
In its May 2014 communication, the FDA wrote:
Although the results of the decision analysis provide important insight for retrievable IVC filters, the FDA is requiring collection of additional clinical data for currently marketed IVC filters in the United States. The studies will address safety questions that remain unanswered for both permanent and retrievable filters. … The data gathered from the [studies] will help the FDA, manufacturers and healthcare professionals assess the use and safety profile of these devices, understand evolving patterns of clinical use of IVC filters and ultimately improve patients care.– United States Food and Drug Administration
Some of these studies are still ongoing, however, a number of manufacturers removed their retrievable filters from the market, presumably due to the safety concerns they presented. CR. Bard Inc., for example, stopped selling a number of its IVC filters in the U.S., though it did not issue a formal recall of the devices. Those devices are now the focus of hundreds of lawsuits filed by patients harmed by the problem filters.
Hundreds of thousands of people have been implanted with retrievable IVC filters over the last decade and a half, leaving them wondering, “What do I do now?”
The FDA told doctors to remove retrievable IVC filters as soon as a patient’s risk for clots subsided. The agency also recommended patients go to follow-up visits with their doctor to decide whether the filter can and should be removed. Oftentimes, a retrievable filter is left in place too long and removal becomes too difficult. This is why removing the filter as soon as blood clot risk subsides is so important.
The longer a filter is left in place, the more likely it is to cause problems. Many patients who do not show signs or symptoms of complications find out their filter has moved or fragmented when they go in for a follow-up visit with their doctor.
These follow-up visits usually include CT scans, which show where the filter is in the body and whether or not it has tilted, moved, or fractured. These tests are expensive; many patients find the medical costs too burdensome and they will put off the tests or won’t get them at all. There are programs available, however, that can help pay the costs of these medical tests.