The Food & Drug Administration can’t ensure the safety of medical devices, according to a report published in the British Medical Journal based on a case study of Cyberonics Inc.’s (NSDQ:CYBX) vagus nerve stimulation device for treating epilepsy.
In 1997, Cyberonics went before the FDA’s neurological devices advisory panel for a review of the device, but according to BMJ contributors Jeanne Lenzer, a journalist, and Dartmouth Medical School Institute for Health Policy and Clinical Practice instructor Shannon Brownlee, the company “offered no definitive explanation” on how the device prevented or reduced seizures, according to their article in the BMJ, "Why the FDA can’t protect the public." Cyberonics presented three clinical studies attesting to the device’s safety, but the studies did not answer whether the device was superior to existing care.
The authors also noted that one of the panelists, Johns Hopkins professor Dr. Steven Piantadosi , told the FDA advisory panel that, "I’m still a little worried about the death rates that we are seeing," concerned that the death rate of 7.3 out of 1,000 patients implanted with the device was too high.
Piantadosi ended up voting in favor of the device’s approval, but the FDA made the approval conditional on a post-approval study to examine the safety of the device. Although the company was ordered to report all serious adverse reactions from its device to the agency, the FDA did not "request and rigorously monitor mortality data related to the VNS," according to Lenzer and Brownlee. The Cyberonics case is "but one example of the gap in post-approval surveillance of medical devices," they wrote.
The FDA relies on reports of injury from medical device makers after their approval, saying its most “comprehensive source of information about the safety and effectiveness” of devices is its Manufacturer and User Facility Device Experience database. The MAUDE database, however, is only capable of picking up "’signals’ of possible safety problems that could be used to trigger more definitive investigation." Lenzer and Brownlee cite the Center for Devices and Radiological Health’s own report detailing the shortcomings in monitoring its own database:
"Challenges related to CDRH’s current data sources, methods, and administrative practices make it difficult for the Center to efficiently and effectively obtain complete information about the risks and benefits of regulated products across the total product life cycle," according to the FDA.