Health Letter, September 2020
By Michael Carome, M.D.
The Food and Drug Administration’s (FDA’s) dangerously lax regulatory oversight of high-risk implanted spinal cord stimulators for pain relief has resulted in unnecessary harm to patients, Public Citizen said in a June 10 report delivered to the FDA commissioner, the agency’s Center for Devices and Radiological Health and key congressional committees.
The report concluded that taken together, its findings demonstrated that there is no reasonable assurance that implanted spinal cord stimulators for pain relief are safe and effective for their FDA-approved uses.
The goals of the report, which was prompted by concerns about the safety of implanted spinal cord stimulators for pain relief that were raised in a 2018 Associated Press investigation, were to better understand the history of the FDA’s regulatory oversight of these devices, identify the deficiencies in this oversight that endangered patients and recommend necessary changes to address those deficiencies.
In a major initial misstep, the FDA improperly categorized older spinal cord stimulators with external transmitters for pain relief as moderate-risk Class II devices but newer totally implanted spinal cord stimulators for pain relief as high-risk Class III devices, even though they have comparable risk profiles. In general, FDA clearance of Class II devices is based on a determination that the device is “substantially equivalent” to a device already on the market, whereas Class III devices require premarket approval applications (PMAs) with data from clinical studies in patients.
Most troublingly, Public Citizen’s report documented that since 2001, the FDA improperly approved several Class III totally implanted spinal cord stimulators for pain relief — which are now the predominant type of spinal cord stimulator used in clinical practice — based on clinical data obtained only from literature reviews of seriously flawed studies of other spinal cord stimulator devices, not studies of the actual devices for which approval was being sought. The report concluded that the FDA in effect has dangerously treated most high-risk Class III spinal cord stimulators as lower-risk Class II devices and allowed them to be marketed using the “substantial equivalent” standard.
The FDA also has misused the secretive and apparently less rigorous PMA supplement process to approve entirely new models of totally implanted spinal cord stimulators for pain relief, as well as major design changes and new uses for previously approved models.
Against this background of recklessly lax oversight, Public Citizen’s report also documented evidence of substantial harm associated with the use of spinal cord stimulators for pain relief. Published literature reviews reveal that implanted spinal cord stimulators have an alarmingly high complication rate — between 30% and 40%.
Moreover, from 2004 to 2019, the FDA received 220,374 adverse event reports for these devices, including 156,817 reports of injuries and 931 reports of patient deaths. Despite this high number of injury reports, there have been remarkably few recalls from 2004 to 2019 for the devices.
The report illustrates that the FDA’s regulatory oversight of implanted spinal cord stimulators for pain relief has had serious, wide-ranging deficiencies for several decades and is emblematic of what’s wrong with the agency’s oversight of medical devices and the serious harm to patients that can result.
To ensure the safety and effectiveness of these devices going forward, Public Citizen urged the FDA to reclassify the stimulators with external transmitters as Class III devices, require controlled clinical trials for any future totally implanted spinal cord stimulators for pain relief, reassess the safety of all these devices and remove any from the market if deemed necessary, and compile and make publicly available a list of all other Class III devices for which PMA approval was granted based on literature reviews of studies assessing devices other than the one for which PMA approval was sought.
Public Citizen also called on Congress to conduct long-overdue oversight hearings and draft legislation to strengthen the FDA’s oversight of medical devices. The report urged Congress, as a first priority, to immediately pass legislation to override the Supreme Court’s 2008 decision in Riegel v. Medtronic, which held that the existing law preempts the right of patients to bring damages claims against medical device manufacturers for injuries caused by high-risk medical devices marketed pursuant to a PMA. The Riegel decision ended a period of more than 30 years in which federal and state laws had worked hand in hand to strengthen device safety. The multiple dangerous weaknesses in the FDA’s regulatory oversight of medical devices documented in Public Citizen’s report make the preemption decision in Riegel a dangerous outcome for patients.