IVC Filter Complications Target of New Five-Year Study

Researchers from the fields of radiology and vascular surgery announced this week that they will launch a new study to determine the safety and effectiveness of inferior vena cava (IVF) filters, which have been linked to a risk of serious problems when some versions are left in place after the risk of a pulmonary embolism has passed. 

IVC filters are small spider-like devices that are implanted into the vena cava to catch blood clots that break free in the body, preventing them from lodging in the lungs and causing a pulmonary embolism.

Some variations are designed to be retrievable and can be removed after the risk has passed. However, several popular models, such as the Bard Recovery and Bard G2 filters, have been found to prone to problems where the legs of the device may break off or perforate the vena cava.

The new study, PRESERVE, will be led and funded by the Society of Interventional Radiology (SIR) and the Society for Vascular Surgery (SVS). The two groups will run a large-scale, multispecialty prospective study whose goal is to determine the proper use of IVC filters.

According to the two groups, the impetus for the study was the FDA’s August 2010 safety alert, which warned about the risk of complications with retrievable IVC filters that are left in place once the danger of a blood clot has passed. According to the agency, at least 921 adverse event reports were received during 2010, with about 328 involving an IVC filter breaking free and migrating through the body, 146 reports of components of the filters breaking loose, 70 involving the inferior vena cava being perforated, and 55 reports of the filter fracturing.

The new five-year study aims to involve 1,800 patients at about 50 locations in the United States.

According to a press release by SIR, the use of the filters and their safety is important because it is estimated that between 350,000 and 600,000 people in the U.S. develop blood clots every year, and up to 180,000 people die of those clots in a single year. But the FDA and others have raised critical questions regarding their safety.

One-in-Four Bard Recovery Filter Systems Fail, Researchers Say

The Bard Recovery IVC filter and Bard G2 IVC filter have been the subject of many product liability lawsuits in recent years, after data suggested that they were associated with a high rate of failures and other problems, which could cause serious and potentially life-threatening injuries.  Pieces of the IVC filters appear to be prone to break or fracture, allowing pieces to flow through the bloodstream travel to the heart, lungs or cause other internal punctures.

According to a study published in the Archives of Internal Medicine in August 2010, the Bard Recovery Filter system failure rate was 25% and the Bard G2 Filter system failure rate was about 12%.  Researchers recommended an immediate halt to the use of the Bard IVC filters to protect patients.

Allegations raised in lawsuits over the Bard G2 filter and the Bard Recovery filter suggest that the manufacturer failed to adequately warn about the risk of problems, including the risks associated with leaving the Recovery or G2 filters in place once the threat of a pulmonary embolism has passed.