Multi-district litigation involving inferior vena cava filters has been ongoing for some time, but C.R. Bard Inc. of Murray Hill, N.J., managed to stave off several claims in a multi-district litigation action in Arizona. Judge David Campbell of the Arizona district court dismissed the plaintiff's failure to warn claims in part because of a lack of evidence that the prescribing physician would have used another device had the device label borne a different set of warnings, but Bard will still have to defend itself on the point of strict liability for purportedly defective design.

The IVC filter has perhaps one of the more convoluted regulatory and legal histories of all implanted medical devices, a story that captures a dozen or more devices from roughly half a dozen manufacturers. In November 1999, the FDA published a guidance for cardiovascular intravascular filters that overwrote a document that was at the time a mere two years old. The scope of the 1999 guidance was limited to filters that attach to the vena cava by means of a series of hooks, which the guidance said are "at the end of several legs or struts which converge at an apex." The guidance said that filters using a significantly different design may require a PMA or a product development protocol.

The 1999 guidance said pulmonary emboli occur roughly 600,000 times a year in the U.S. and caused the deaths of 200,000, but more recent data from the Centers for Disease Control and Prevention pegs the prevalence of pulmonary emboli at closer to 900,000. CDC said as many as 100,000 die each year, while the 10-year rate of recurrence is 33 percent.

Prophylactic use arises after 1999 guidance

In a paper posted at Endovascular Today in 2005, two FDA managers, including Dorothy Abel, noted that the design of such devices and the related mechanisms of action were "relatively well defined," although they said that a sponsor may have to provide "a substantial amount of preclinical and/or clinical data" to obtain a 510(k) for some devices. The paper said that the retrievable version of the IVC filter had emerged after the issuance of the 1999 guidance, and that some physicians had subsequently commenced with implant of these devices without documented pulmonary emboli.

One example of this use of IVC filters is the prophylactic use of the devices in trauma patients who face surgery and thus cannot be anticoagulated. The Endovascular Today paper said that such short-term use of these filters had disclosed previously unknown failure modes, which led to the agency's reassessment of the standard of evidence needed to clear a 510(k). Medicare coverage of device removal began in January 2012 with the adoption of CTP code 37193, which pays an outpatient hospital facility fee of nearly $2,500.

The FDA had issued a safety warning for these devices in 2010, based on a review of more than 900 adverse events, but the agency has removed that advisory, the same fate as befell a safety communication the FDA issued in 2014. Utilization had risen steadily over the five years leading up to the 2010 advisory for a net increase of 22 percent. In the four years following the 2010 advisory, however, utilization dropped 29 percent according to an article in the September 2017 issue of JAMA Internal Medicine, which was titled "Association between contemporary trends in inferior vena cava filter placement and the 2010 US Food and Drug Administration advisory."

The question of medical practice regarding device removal was undertaken in the Journal of Vascular Surgery (JVS), which said that physicians were increasingly implanting IVC filters for prophylaxis in patients at transient risk of pulmonary embolism despite the absence of a diagnosed event. The authors said the data suggest the devices should be extracted from this patient group no later than 59 days post-implant because the risk of an embolism fades sufficiently to roughly equal the hazards associated with continued presence of the implant. The title of the article in the October 2013 issue of JVS is "Decision analysis of retrievable inferior vena cava filters in patients without pulmonary embolism."

The July 26 decision in Hyde v. C.R. Bard revolves around a filter that was implanted in the plaintiff in February 2011, although the procedure took place in Wisconsin, prior to the plaintiff's relocation to Arizona. The Bard G2X filter had demonstrated on imaging to have tilted within the inferior vena cava, perforating the vessel while a strut had lodged in the right ventricle of the heart. Plaintiff Lisa Hyde had the device removed in August 2014, and the judge in the case declared that the laws in effect in the state of Wisconsin at the time of implant should govern the proceedings, particularly since the patient did not experience any complications until after relocating.

The court noted that under Wisconsin law, a product is deemed defective only if it is not reasonably safe. The outcome in Medtronic v. Lohr, the 1996 case that brought federal preemption for class II devices to an end, was cited as a demonstration that the FDA review for 510(k) products is focused on substantial equivalence rather than safety, and thus the court indicated it was not required to determine whether the plaintiff had sufficiently addressed the question of product defect.

Bard was not entitled to summary judgment on strict liability connected to the plaintiff's claim that the G2X filters were more strongly associated with adverse events.

On the question of design defect, the plaintiff's expert testimony indicated that Bard could have introduced safety features, such as caudal anchors, earlier than the company had. Bard countered with the argument that the plaintiff had said that another IVC device was defective despite the use of caudal anchors, but the court nonetheless determined that the plaintiff had presented evidence that the G2X could have been manufactured so as to reduce the risk of adverse events.

Physician no help to plaintiff

Bard scored a win on the point of a failure to warn claim because the plaintiff offered no evidence to back the assertion that an adequate level of warning for the device "would have prevented the use of the Bard filter in this case." The physician is said to have testified to having no recall of his advice to the patient regarding device selection, adding that he did not remember the patient. When asked whether he would have opted for a different device had he believed the G2X was associated with a higher rate of adverse events than other available filters, the physician is said to have replied, "I tend to trust the FDA more than individual companies."

The 4,100 cases that have been grouped in this multi-district litigation will be heard in the Arizona district court later this year, but the company has had some success in these IVC filter cases. While Bard lost a $3.6 million verdict earlier this year, the company scored a legal win in June 2018 when a jury in Arizona determined the company had adequately warned of the risks associated with the Eclipse filter. The trial for the G2X and several other filters will commence Sept. 18.

Troy Kirkpatrick, a spokesman for Bard, said the company is "pleased with the court's ruling because it supports the fact that Bard provided physicians with the appropriate information to make informed treatment decisions."