Horrifying medical device malfunction: Abdominal implant erupts from leg

On May 7, 2011, Georgia resident Tonya Brand noticed a pain on the inside of her right thigh. As the pain grew worse in the 4- to 5-inch area of her leg, she headed to a hospital. There, doctors suspected she had a blood clot. But an ultrasound the next day failed to find one. Instead, it revealed a mysterious toothpick-sized object lodged in Brand's leg.

Over the next few weeks, the painful area became a bulge, and on June 17, Brand put pressure on it. Unexpectedly, the protrusion popped, and a 1.5-inch metal wire came poking out of her leg, piercing her skin.

The piece of metal was later determined to be part of a metal filter she had implanted in a vein in her abdomen more than two years earlier, in March 2009, according to a lawsuit Brand filed. The filter was initially placed in her inferior vena cava (IVC), the body's largest vein tasked with bringing deoxygenated blood from the lower body back up to the heart. The filter is intended to catch blood clots, preventing them from getting into the lungs, where they could cause a life-threatening pulmonary embolism. Brand got the IVC filter ahead of a spinal surgery she had in 2009, which could boost her risk of clots.

After the wire burst from her leg, X-rays showed that another metal shard had broken free from the filter and traveled. The second one lodged itself near her spine, which is where it remains—it's too risky to try to remove. Brand underwent surgery in July 2011 to try to remove the rest of the filter in her IVC, but the surgeons failed to collect the remnants after several attempts.

Undisclosed data

After Brand filed her lawsuit in 2013, other patients filed lawsuits against the IVC filter maker, Cook Medical, in 11 other districts. The lawsuits were later consolidated into one case. During the litigation, expert witnesses and lawyers discovered red flags in safety data and trial design that were not previously publicly reported or made available to patients. That included eight suspicious deaths among clinical trial participants and perforated veins among sheep used in animal experiments. But, those revelations have remained out of public view due to a court confidentiality order—until now, at least.

In a report published this week in the Annals of Internal Medicine, researchers involved in the litigation and other experts reveal what's in the newly unsealed court documents, and they call for regulatory reform in medical device approvals. The litigation revealed numerous weak points in the regulatory review of Cook's IVC filter, called Celect.

"The Celect case highlights the need to improve transparency and integrity in medical device regulation," the authors, led by Harlan Krumholz, a cardiovascular medicine expert at Yale, wrote.

Cook Medical did not respond to Ars' request for comment for this story.

Cook's Celect was authorized by the Food and Drug Administration in 2007 through a 510(k) pathway. This requires device makers only to prove to the FDA that their device is similar to already-authorized devices and is "substantially equivalent" in safety and efficacy. IVC filters, in general, have been around for many decades, stretching back to the late 1960s.

Dearth of details

The public summary of Celect's authorization was short on details, only noting that lab bench and animal testing had been done. There was no note of any safety concerns. But, court documents revealed that there were safety concerns—and the FDA had initially denied authorization. Cook had tested the filter in 20 sheep, with each animal receiving two IVC filters that were later retrieved. Of the 40 implanted filters, six were found to have perforated the animals' veins, which caused the FDA concern. However, Cook resubmitted its application to the FDA without any new testing or design changes, and it won authorization. The FDA didn't explain why it changed its mind.

In 2008, Cook received FDA authorization to expand Celect's labeling, at which point the company referenced a clinical study. The company said that among 43 test patients, the filter was retrieved with a 95 percent success rate. But no other details were provided in public FDA documents. In 2009, Cook published part of the study in the Journal of Vascular and Interventional Radiology (JVIR), which revealed that the 43 patients were part of a 95-participant cohort. There was no randomization of participants and no control group in the study.

Court documents revealed that the study may have been designed to obfuscate adverse events. By industry standards, any instance where the filter perforated a vein would have been considered a safety event. But Cook only considered a perforation a safety event if there was evidence of bleeding. Yet, the trial design didn't require sensitive imaging—computed tomography (CT) scans—that would be able to detect bleeding reliably. None of these details were mentioned in FDA's public documents.

Suspicious deaths

In the 2009 JVIR article, Cook acknowledged that two deaths occurred in the study but suggested that there were no "device/procedure-related adverse events." Yet, the academic committee tasked with overseeing the study had, in fact, determined the two deaths to be device-related, according to Krumholz and colleagues. Further, Cook's complete study report, which was unsealed during the litigation, revealed that there were eight suspicious deaths during the study, not just the two. Cook did not conduct autopsies on all eight patients who died. The FDA did not mention the deaths in its summary of the trial.

In 2010 and 2014, the FDA issued general safety warnings about IVC filters. The agency recommends that they are retrieved as soon as clinically possible after the risk of blood clots has declined. Earlier this month, FDA scientists were co-authors on a JAMA study finding that of the tens of thousands of patients who get IVC filters implanted each year, only a minority have them retrieved. The authors call for clinicians to perform timely retrievals to avoid adverse events.

Still, Krumholz and his co-authors say reforms are necessary for patients to be fully informed of the safety of medical devices. "[U]ncertainty remains for the thousands of patients who had Celect filters implanted in their bodies," the experts write. "Although all devices carry risks and benefits, litigation should not be required for patients and clinicians to access safety information."

Brand still lives with pieces of Cook's IVC filter lodged in her body, which poses life-threatening risks and necessitates lifelong clinical monitoring. She settled her lawsuit with Cook on undisclosed terms. Other litigation is still ongoing.