Medical device maker C.R. Bard replaced a blood-clot filter associated with more than two dozen deaths and hundreds of problems with a version Bard knew had similar and potentially fatal flaws soon after it was put on the market.
Company records obtained by NBC News show that within four months of receiving Food and Drug Administration (FDA) clearance to sell the G2 filter, C.R. Bard became concerned about reports of failures for G2 series filters, designed to replace the Recovery filter. Instead of recalling the G2 filter, and the virtually identical G2 Express, Bard kept them on the market for five years, until 2010, selling more than 160,000 of the devices.
At least 12 deaths and hundreds of problems are now linked to the G2 series filters, according to both Bard and FDA records, NBC News reports. “All of the data that we’ve seen in our own studies, as well as other clinician researchers’, is that this device consistently fractures, consistently causes major complications,” said Dr. William Kuo, an interventional radiologist who runs Stanford Health Care’s IVC Filter Clinic, which specializes in removing failed blood-clot filters. “The number of complications, the frequency of severe failures makes it obvious that it was never safe to be implanted.”
Blood-clot filters are implanted in an estimated 250,000 people each year; Bard is one of 11 manufacturers of these devices. The spider-shaped Bard filters are implanted in the inferior vena cava — the largest vein in the body — to stop blood clots from moving to the heart and lungs, where they could be fatal. When a retrievable IVC filter fractures and pieces migrate, the patient can experience severe pain, bleeding, further embolus, and other life-threatening complications.
The Recovery filter received FDA clearance in 2002, but reports of deaths and injuries associated with the filter moving and breaking steadily climbed, according to NBC News. A study commissioned by Bard showed that the Recovery filter had higher rates of relative risk for death, filter fracture, and movement than all of its competitors.
Bard not recall the Recovery filter, but in 2005 replaced it with the similar G2 series of filters. Bard’s records and hundreds of reports to the FDA indicate that the modified G2 filters did not solve the problems. A confidential memo from December 2005 expresses concern about “problems with . . . migration,” “tilting” and “perforation.” The memo writer, a Bard vice president, noted that another Bard filter on the market had virtually no complaints, and the writer wondered why doctors were not using that one rather than the G2, according to NBC News.
Bard kept the G2 series filters on the market until 2010. One G2 Express recipient had emergency surgery to remove a filter that had moved dangerously close to his heart. Dr. Kuo performed the surgery after two other surgeons declined to attempt the removal because of the filter’s precarious position. Kuo discovered that three legs had already broken off the filter and traveled to the man’s lungs. Two partially broken legs broke away during the operation. One traveled into the right ventricle and could have killed the man.
Kuo estimates that he has removed 1,000 failed filters in the last ten years and said he has removed more Bard filters than any other make. Kuo said the Recovery and G2 filters should have been pulled from the market, according to NBC News.
The Society of Interventional Radiologists, Society for Vascular Surgery, and filter manufacturers, including Bard, have just begun a large clinical trial to examine the safety and effectiveness of filters now on the market.