IVC Filters Not As Effective As Blood Thinners In Preventing Embolism: Study

A new study questions the effectiveness of retrievable inferior vena cava (IVC) filters, which have become increasingly popular for prevention of blood clots among at-risk patients. 

IVC filters are small, spider-like devices that are implanted into the inferior vena cava to “catch” blood clots that may break free from the deep veins, and prevent the clot from entering the lungs and causing a pulmonary embolism.

In a study published in the Journal of the American Medical Association (JAMA) on April 28, French researchers indicate that patients who receive an IVC filter may be twice as likely to suffer a pulmonary embolism, often fatal, than peers who were prescribed blood thinners alone.

Researchers from a number of French hospitals and universities conducted a randomized clinical trial on about 400 patients who had been hospitalized after suffering an acute, symptomatic pulmonary embolism associated with lower-limb vein thrombosis. Half were given anticoagulants and half were given both blood thinners and an IVC filter implant.

The study found that after just three months, six of the patients who had received a filter suffered a recurrent pulmonary embolism. All of those patients died. Another three patients experienced problems with the IVC filter, known as filter thrombosis, where parts or all of the filter broke off and traveled to the lungs or heart.

By comparison, only three patients who were given blood thinners suffered another pulmonary embolism; two of whom died.

“Among hospitalized patients with severe acute pulmonary embolism, the use of a retrievable inferior vena cava filter plus anticoagulation compared with anticoagulation alone did not reduce the risk of symptomatic recurrent pulmonary embolism at 3 months,” the researchers concluded. “These findings do not support the use of this type of filter in patients who can be treated with anticoagulation.”

IVC Filter Health Concerns

In recent years, removable IVC filters have been the subject of much debate within the medical community about the safety and effectiveness, with several types associated with reports of severe and sometimes fatal complications.

Amid reports of problems, the FDA issued a warning about the risk of IVC filter problems in August 2010, indicating that hundreds of adverse event reports had been received involving retrievable IVC filters that broke free and travelled to other areas of the body or caused other injury.

In April 2012, a study published in the medical journal Cardiovascular Interventional Radiology indicated that nearly 100% of Cook Celect and Gunther Tulip IVC filters perforated patients’ venal cava wall within 71 days of being implanted. The study also found that 40% of the filters became tilted and out of position.

A study published in the medical journal JAMA Internal Medicine in March 2013 raised questions about the effectiveness of IVC filters, indicating that less than 10% of filters evaluated in the study were successfully removed from patients and 8% of recipients of IVC filters suffered a pulmonary embolism despite the device’s presence.

In May 2014, the FDA urged doctors to remove IVC filters within about one to two months after the risk of a pulmonary embolism has passed, suggesting that many doctors were not adequately warned about the importance of retrieving the devices.

IVC Filter Lawsuits

A growing number of Cook IVC filter lawsuits have been filed in courts throughout the country, each raising similar allegations of problems with the Celect and Gunther Tulip filters.

Since October 2014, all Cook Celect lawsuits and Cook Gunther Tulip lawsuits have been consolidated in the federal court system as part of an MDL, or multidistrict litigation, which is centralized for pretrial proceedings before U.S. District Judge Richard L. Young in the Southern District of Indiana.

The litigation raises similar allegations of design defects to those brought in Bard Recovery IVC filter lawsuits and Bard G2 IVC filter lawsuits, which have also been linked to reports of problems where the devices may fracture, migrate or perforate internal organs.