Cyberonics’ Vagus Nerve Stimulator Device Linked to 900 Deaths
Two contributing authors to the BMJ criticized "the FDA's approval and follow-up" of Cyberonics' vagus nerve stimulator device, which has been cited in "900 FDA-reported deaths." FDA spokeswoman Karen Riley said "the agency is engaged in an ongoing effort to improve overall medical device safety monitoring." In light of this recent report, noted expert Jerry Avorn, M.D., offered several recommendations for improving medical device safety. This articles summarizers the findings and Avorn's recommendations.
Healthday reported, “The US Food and Drug Administration (FDA) is not doing its job of properly monitoring the safety of medical devices” The report, published in the Nov. 3 online edition of the BMJ, stated that the FDA “is lax in both its initial approval of devices and its ongoing monitoring of related problems.”
MEDPAGE TODAY also criticized the The FDA’s regulation of medical device describing it “woefully inadequate, potentially contributing to hundreds of deaths in the case of one device in particular”.
The vagus nerve stimulator was approved in 1997 for treatment-resistant partial seizures. The device (sold as the VNS Therapy System)—manufactured by Cyberonics—has been linked to 900 deaths yet it remains on the market. Neither Cyberonics nor the FDA have properly investigated the system’s role, if any, in the reported deaths. While Cyberonics conducted post-approval studies, none of the studies included mortality data.
In response to the BMJ article, Cyberonics has issued the following statement:
“Available data demonstrate that all-cause mortality rates for VNS Therapy patients are less than half the rates in the comparable non-VNS epilepsy patient population (6.8 vs. 14-19 per 1,000-patient years),” the statement said.
Jerry Avorn, MD, of Harvard Medical School in Boston, and international expert on regulatory affairs of devices and pharmaceuticals, submitted an editorial noting:
“The standards for device approval and surveillance have fallen far below those for drugs, and even those that would be dictated by common sense…It would be unthinkable for a drug company to go to the [FDA] or the European Medicines Agency and say, in effect, ‘This new drug is much like an older product we sell, except that we have added a new amine group and modified one of the side chains. Apart from that, it’s pretty close, so we won’t be doing any new clinical tests on it. When can we begin marketing?’ But this is essentially what happens with many new medical devices when they are approved.”
Dr. Avorn also offered the following specific criticisms:
- Most MAUDE death reports, written by manufacturers, contain descriptions so brief that no definitive cause of death can be inferred;
- Recordkeeping for device implants is often minimal—a detailed definition of the device itself is not routinely recorded in most clinical databases,” he wrote.
- The “substantial equivalence” standard for clearing new products under the so-called 510(k) process is ineffective and unsafe;
- The MAUDE system is not as effective as AERS and similar systems in Great Britain and the Netherlands for reporting and analyzing adverse events;
- Post-marketing safety reviews should be conducted by an FDA unit separate from the office that grants approvals.
“The disappointing history of device regulation reminds us that it is not wise to allow the safety of a medical intervention to be judged primarily by the people who approved it and the companies that manufacture it,” Avorn wrote.
Other reported device failures include:
Bone morphogenetic protein-2 Spinal fusion devices (possibly linked to life-threatening complications in some patients)
Menaflex (A meniscal replacement implant for damaged knees) The agency took steps to withdraw the Menaflex knee implant, due to defective clearance process.