Doctors Recommend Further Research into Safety and Effectiveness of IVC FiltersJan 13, 2016
In a case study in Respiratory Medicine Case Reports (June 2015), doctors from Southern Illinois University and the University of Texas Medical Branch at Galveston, recommend further research is needed into the long-term safety and effectiveness of IVC (inferior vena cava) filters.
The IVC filter is inserted via a catheter into the inferior vena cava-the body's main vein-to help keep blood clots from traveling to the heart and lungs. According to the Mayo Clinic, this procedure is typically used for people who cannot take anticoagulant drugs (the first-line treatment) or when drug therapy does not work well enough or quickly enough.
There are a number of risk factors for dangerous venous blood clots, including previously having had a venous blood clot or a pulmonary embolism (blockage of an artery in the lung). Additional risk factors include heart disease, smoking, obesity, certain cancers and chemotherapy drugs, and prolonged immobility, such as after surgery, heart attack, or leg fracture. Sitting in a cramped position for a long period, in a car or plane, for example, can increase clot risk. Pregnancy also increases risk: the baby pressing on veins in the pelvis can slow blood return from the legs, the Mayo Clinic explains.
But IVC filters can lead to complications, at the time of insertion or later. Complications include filter migration, filter occlusion (blockage), filter misplacement, and filter fracture with fragment embolization.
C.R. Bard, a leading maker of IVC filters, faces numerous lawsuits over injuries associated with its Recovery and G2 IVC filter lines. In August 2015, the lawsuits were consolidated into a multidistrict litigation in the District of Arizona.
Bard’s Recovery IVC filter line came on the market in 2002 and has been associated with more than two dozen deaths and hundreds of injuries. Bard replaced the Recovery with the G2 version, which is now linked to at least 12 deaths and hundreds of problems. NBC News reports that Bard knew the G2 filters had flaws similar to those of the Recovery filters within months after the G2 filters came to market.
In its investigation, NBC News obtained records indicating that within four months of receiving Food and Drug Administration (FDA) clearance to sell the G2 filter, Bard officials expressed concern about reports of G2 filter failures. But the firm did not recall the G2 filters, instead keeping the line on the market until 2010. Bard sold more than 160,000 G2 filters in that time.
Each year, about 250,000 people have IVC filters implanted to prevent blood clots from moving into the heart and lungs, where they could be fatal. Some filters are intended to remain in the body permanently, while others are removed when the clot danger has passed. When pieces of a filter break off and migrate, the patient can experience severe pain, bleeding, further embolus, and other life-threatening complications. Though the doctors did not attempt to remove the broken piece of the IVC filter in the patient in their case study in Respiratory Medicine Case Reports (and she remained asymptomatic), they concluded that such cases demonstrate the need for "strict compliance with the current guidelines of IVC filter insertion, adequate follow up, and retrieval of the filters when they are no longer indicated."