Implanted spinal cord stimulators for pain relief pose high risk for injury

Medical device companies and doctors prescribe spinal cord stimulators as a cure for millions of patients who suffer from pain disorders. Touted as an alternative to opioids, spinal cord stimulators have become one of the fastest growing sectors in a $400 billion medical device industry. Manufacturers and doctors push these devices to patients who have injury resulting in chronic pain and to an aging population seeking chronic pain relief. Sixty-thousand spinal cord stimulators are implanted annually.

Although the mechanism of the purported pain relief from inducing electrical stimulation of the spinal cord is yet unknown, several theories have been proposed. It is surmised that the devices block transmission of pain signals by nerve fibers in the spinal cord to the parts of the brain involved in pain perception. Theories, though plausible, still remain unproven. In practice, electrode placement and electrical stimulation dosing for spinal cord stimulators are done empirically.

Spinal cord stimulators use electrical current to block pain signals before they reach the brain. These devices rely upon a complex network that sends electrical currents through wires placed along the spine, using a battery implanted under the skin. An external remote controls the device.

Spinal cord stimulators are more dangerous than many patients are led to believe. In fact, according to a recent Associated Press (AP) investigation, they account for the third highest number of medical device injury reports to the U.S. Food and Drug Administration (FDA).  The FDA has flagged over 80,000 incidents caused by spinal cord stimulators since 2008. Only metal hip replacements and insulin pumps have logged more injuries.

Published literature reviews and an analysis of data from the FDA’s Manufacturer and User Facility Device Experience (MAUDE) database reveal that implanted spinal cord stimulators for pain relief can cause substantial harm. Overall complication rates for such stimulators documented in literature reviews were 30% to 40%.

FDA data shows shocks, burns and spinal cord damage ranging from muscle weakness to paraplegia have been reported. Common complications include lead migration, lead fracture, implant-related pain, infection, hematomas, seromas, and cerebrospinal fluid leakage. One rare but particularly troubling adverse event is chronic scar tissue formation around epidural leads, which can lead to spinal compression and myelopathy with various forms of paresis and sensory loss.

FDA data shows more than 500 deaths related to spinal cord stimulators though the data fails to differentiate between death caused by the stimulator itself or by surgery to implant the device.

Although manufacturers and doctors insist spinal cord stimulators are safe and that they reduce pain for most patients, data shows otherwise. At fault, the FDA’s abbreviated approval process for medical devices as well as faulty and misleading device classification. The FDA’s record of slow response when citing manufacturers is also at fault even when corrections to life-threatening devices are sought.  When major problems arise, devices are rarely pulled from the market. Additionally, the FDA will not disclose the number of devices implanted annually which could assist in calculating failure rates.

Medical device manufacturers spend billions to influence regulators, hospitals and doctors offering financial payouts to individuals and institutions to promote the implanting of these devices. Last year alone in the U. S., disclosed payments to doctors and hospitals totaled $600 million in consulting fees, research, travel and entertainment expenses, according to analysis of data from the Centers of Medicare & Medicaid Services.  Lobbying records show that the top four spinal cord stimulator manufacturers have spent more than a combined $22 million since 2017 in an attempt to influence legislation benefitting overall business (this includes spinal cord stimulators as well as other manufactured devices).

It’s no wonder half of the patients interviewed as a result of the Associated Press investigation said they felt pressured to consent to implantation of a spinal cord stimulator because they feared their doctors would stop prescribing pain medication.

In 1976, Congress passed the Medical Device Amendment, a law meant to assure Americans that devices recommended by their doctors would do good and not harm.  To implement this law, the FDA created three classes of medical devices. High-risk products like spinal cord stimulators are designated to be held to the most rigorous clinical testing standards.  In reality, the vast majority of devices go through a far less stringent review process providing them with an easy path to market. They are fast-tracked to market because they are deemed “substantially equivalent” to products already approved for use.

The AP investigation found the FDA allowed some spinal cord stimulators to reach the market without new clinical studies, approving them largely based on results from studies of earlier spinal cord stimulators.  A detailed report published on June 10, 2020 from Public Citizen—a national nonprofit representing consumer interests and manufacturing accountability on a broad range of issues including consumer rights in the marketplace and drug and medical device safety—has documented the FDA’s dangerously lax regulatory oversight of high-risk implanted spinal cord stimulators for pain relief.  The report shows that these devices result in unacceptable risk to patients. Further, the Public Citizen report demonstrates that there is no reasonable assurance that implanted spinal cord stimulators for pain relief are safe and effective for their FDA-approved uses.

The report found that the FDA treated most high-risk Class III spinal cord stimulators for pain relief as lower-risk Class II devices and essentially allowed them to be marketed using the “substantial equivalent” standard. The report also found that the FDA had misused the secretive and apparently less rigorous premarket approval application (PMA) supplement process to approve multiple 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.

The Public Citizen report documents evidence of substantial harm associated with use of spinal cord stimulators for pain relief. According to the report, 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.

Classifications for devices by class are cited. Class 1 devices pose the least risk. Class II devices require a premarket notification submission and are cleared for marketing based upon a determination that the device is substantially equivalent to a legally-marketed device not subject to a PMA.  Class III devices generally require FDA approval of PMAs prior to marketing and, usually, submission of clinical data on use of a device in humans to provide reasonable assurance that device is safe and effective.

The FDA arbitrarily divided implanted spinal cord stimulators for pain relief into Class II and Class III based upon whether the devices had an external transmitter and power source or were totally implanted.  Findings from the Public Citizen report state that the FDA needs to initiate regulatory actions to reclassify and more tightly regulate implanted spinal cord stimulators with external transmitters for pain relief from Class II to Class III and require PMA submission for all such devices currently on the market. 
Secondly, according to the report, the FDA should provide to the public a reliable list of adverse events and the number of their occurrences for each implanted spinal cord stimulator model and lead kit.

The Public Citizen report also found that post-market surveillance by the FDA appeared deficient. Given the large number of serious adverse events associated with the use of implanted spinal cord stimulators for pain relief, the relatively small number of recalls and the lack of any Class 1 recalls, these findings are troubling and suggest inadequate post-market surveillance by the agency.

Lack of pre-market and post-market surveillance of spinal cord stimulators has resulted in a remarkable number of reports of injuries associated with the use of these devices. In addition, many patients who may not have been good candidates for this type of pain management were encouraged to have these devices implanted with dire consequences.  Many are permanently or partially bedridden or are unable to enjoy lifestyles they once embraced.

If you or someone you know has been injured by an implanted spinal cord stimulator, please call our firm at 877.529.3707 for a free consultation with one of our attorneys.

Sources:

Implanted Spinal Cord Stimulators for Pain Relief: Illustrating the FDA’s Dangerously Lax Oversight of High-Risk Implantable Medical Devices, Michael A. Carome, M.D., Health Research Group, published by Public Citizen, 2020

Patients Shocked, Burned by Device Touted to Treat Pain, Mitch Weiss and Holbrook Mohr, Medicalxpress, 2018.

Spinal Cord Stimulation for Chronic Back and Neck Pain, Neel Mehta, M.D., SPINE-health, 2016.

Spinal Cord Stimulator Problems That You Need to Know About, Spinal Cord Team, Spinal.Cord.com, 2018.

 

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