A recently published study suggests patients may be subjected to IVC filter overuse, putting them at an increased risk of serious side effects. The study found certain patients who received an inferior vena cava (IVC) filter did not show a statistically significant increased survival rate compared with those who did not receive the filter. This is a concern because IVC filters have been linked to catastrophic adverse events, including device migration and organ perforation.
Study Examines Mortality Linked to IVC Filter Use
The study was published in January 2017 in the journal JAMA Surgery. Researchers examined whether trauma patients who were given an IVC filter had an increased risk of surviving their trauma compared with patients who did not receive an IVC filter. In conducting the research, the study’s authors noted that the use of IVC filters in trauma patients admitted to the hospital has risen in recent years, despite there not being enough “high-quality evidence” to prove they are effective at increasing patient survival rates.
In following up with 451 trauma patients who received an IVC filter and 1343 trauma patients with no filter, researchers found that once patients survived more than 24 hours from the initial injury, there was no significant difference in mortality between the two groups of patients, even in patients who had deep vein thrombosis or pulmonary embolism when the filter was implanted.
“The research herein demonstrates no significant difference in survival in trauma patients with vs without placement of an IVC filter, whether in the presence or absence of venous thrombosis,” researchers wrote.
Lack of Effectiveness Compounds IVC Filter Overuse Worries
That IVC filters are used without significant evidence confirming they work is a concern on its own, but studies suggest that not only are the IVC filters often left implanted for too long, but they also come with an increased risk of serious complications, including breaking and puncturing or perforating internal organs.
Inferior vena cava filters are implanted in the patient’s inferior vena cava to prevent blood clots from reaching the patient’s lungs. They are used for patients who cannot tolerate anticoagulant therapies. Retrievable IVC filters are those that are meant to be implanted for only a short time and then taken out once the risk has passed, such as after a serious injury, when the risk of a blood clot and pulmonary embolism is high. The U.S. Food and Drug Administration (FDA), however, has issued warnings that retrievable filters have been left implanted for too long, increasing the risk of device breakage. This IVC filter overuse could have devastating consequences for the patient.
“For patients with retrievable filters, some complications may be avoided if the filter can be removed once the risk of pulmonary embolism has subsided,” the agency wrote. “The FDA is concerned that retrievable IVC filters, when placed for a short-term risk of pulmonary embolism, are not always removed once the risk subsides.”
The number of retrievable filters left implanted is reportedly high. According to a 2013 study published in the Journal of Vascular Surgery: Venous and Lymphatic Disorders, if the risk of pulmonary embolism has passed, the retrievable IVC filter should be removed between 29 and 54 days after implantation. Despite this, as many as 50% of removable filters are left implanted indefinitely.
“Although the true risk of developing a complication after successful placement of an IVC filter is unknown, the risk would be expected to increase with the duration of implantation, as with any chronic implant,” researchers wrote. “This raises safety concerns for patients who received IVC filters with the expectation that implantation would be temporary but whose filters are not removed when the need for filtration has subsided.”
IVC Filter Adverse Reactions
Among the adverse events linked to the IVC filter overuse are:
- Device migration (where the device moves from the implant location)
- Filter fracture
- Movement of all or part of the filter to the heart or lungs
- Perforation of vital blood vessels
- Difficulty removing the filter
According to a 2015 NBC report, at least 27 deaths have been linked to C.R. Bard IVC filters, while hundreds of patients were injured.
IVC Filter Lawsuits Filed
Lawsuits have been filed against two medical device manufacturers for their defective products, Cook IVC filters, and C.R. Bard IVC filters, with lawsuits against both companies consolidated for pretrial proceedings. As of March 15, 2017, Bard faces 1,584 consolidated actions in MDL 2641, while Cook Medical faces 1,597 consolidated actions in MDL 2570.
Internationally, Health Canada has issued its own safety warning regarding IVC filters, alerting Canadians that up to 121 incident reports involving the filters have been filed with Canadian regulators.
IVC filter lawsuits filed against both companies allege the device makers knew or should have known about the risks associated with the filters, but failed to alert patients or physicians to the risks.