The U.S. Food and Drug Administration (FDA) is reminding health care providers of the importance of conducting a trial stimulation period with patients to confirm satisfactory pain relief before implanting a spinal cord stimulator (SCS).

As part of the its ongoing monitoring of the safety and effectiveness of medical devices, including the review of published literature and adverse event and product reports, the FDA continues to receive reports of serious side effects associated with implanted SCS. As a result of this review, the FDA is reminding health care providers of the importance of conducting a stimulation trial before implanting an SCS and providing health care providers with additional recommendations.

Recommendations for Health Care Providers

• Conduct the trial stimulation as described in the device labeling to identify and confirm satisfactory pain relief before permanent SCS implantation.
• Permanent SCS should only be implanted in patients who have undergone and passed a stimulation trial.
• Health care providers typically perform a stimulation trial on a patient for 3-7 days, and success is usually defined by a 50 percent reduction in pain symptoms. Inform your patients about the risks of serious side effects and what to expect during the trial stimulation.
• Before implantation of any SCS, discuss the benefits and risks of the different types of implants and other treatment options, including MRI compatibility of the devices.
• Before implantation of any SCS, provide your patient with the manufacturer's patient labeling and any other educational materials for the device that will be implanted, and inform the patient of the risks, benefits and what to expect during the use of the implanted SCS they will receive.
• Develop an individualized programming, treatment, and follow-up plan for SCS therapy delivery with each patient.
• Provide your patient with the name of the device manufacturer, model, and the unique device identifier (UDI) of the implant they received.

Background

Implanted SCS are offered as an aid to cope with unmanageable chronic pain of the trunk and limbs, including one-sided (unilateral) or two-sided (bilateral) pain associated with conditions such as failed back surgery syndrome, or unmanageable low back and leg pain. It is estimated that 50,000 such devices are implanted annually. In addition, in many cases the device is offered as a treatment to patients who are not eligible for or who have failed other therapies; for many of these patients, these devices offer the opportunity for a significant improvement in debilitating symptoms.

The FDA recently reviewed the medical device reports (MDRs) received between July 27, 2016 and July 27, 2020 associated with spinal cord stimulation devices intended for pain. During this period, the FDA received a total of 107,728 MDRs related to spinal cord stimulators intended for pain, including 497 associated with a patient death, 77,937 with patient injury, and 29,294 with device malfunction. The MDRs include Patient Problem Codes (PPCs) and Device Problem Codes (DPCs), which describe serious side effects on a patient and device failures that may be related to the product, respectively. Each MDR may have more than one PPC and DPC. The most commonly reported PPCs and DPCs for spinal cord stimulators are shown in Tables 1 and 2 below. The percentage listed in the tables represents the proportion of received reports noting that event type and is not an estimate of the proportion of implanted patients that may experience the event.

Table 1. Most Frequently Reported Patient Problem Codes

Table 2. Most Frequently Reported Device Problem Codes

The most common PPC, the failure to achieve or maintain adequate pain control, highlights the need for patients to undergo and demonstrate an adequate trial stimulation prior to implantation. The most common reported DPCs are consistent with those expected with battery-powered stimulation devices intended for longer-term implantation and therapy.

The 497 reports coded as a patient death represent 428 unique events which were reported to the FDA between July 27, 2016 and July 27, 2020 and associated with devices implanted between November 2005 and July 2020. The average age of the patient in these reports was 69 years, and reports noted the presence of comorbidities including malignancy, chronic diseases (including Parkinson’s Disease, diabetes, dementia, and heart disease), and acute illness or injury (including influenza, infection, suicide, and substance abuse). In approximately 30 percent of the cases where times to event were available, the death occurred within 30 days of implantation. However, none of the reports provide enough information to conclude that the device caused or contributed to the death.

When assessing MDRs for any device, it is important to consider several critical limitations of mandatory and voluntary reporting, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data.  In addition, the incidence or prevalence of an event cannot be determined from this reporting system alone due to potential under-reporting of events and lack of information about frequency of device use. Furthermore, the submission of an MDR often does not provide enough information to establish a causal relationship between the device and the reported event.

FDA Actions

The FDA continues to evaluate information about spinal cord stimulators in medical device reports (MDRs), voluntary reports, current medical literature, information exchanged with other U.S. and international regulators and scientific experts, and from ongoing FDA-mandated postmarket studies. The FDA plans to inform the public if significant new information becomes available.

Reporting Problems with a Medical Device

The FDA encourages health care providers, patients, and care givers  to report any adverse events or suspected adverse events experienced with SCS.

Prompt reporting of adverse events can help the FDA identify and better understand the risks associated with medical devices. In some cases, the FDA may contact you for additional information. The FDA will keep the identities of personnel reporting the event and the patient confidential.

ADDITIONAL RESOURCES

• McKenzie-Brown A. Spinal cord stimulation: Placement and management. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. https://www.uptodate.com (Accessed on August 2020).
• The Appropriate Use of Neurostimulation of the Spinal Cord and Peripheral Nervous System for the Treatment of Chronic Pain and Ischemic Diseases: The Neuromodulation Appropriateness Consensus Committee Neuromodulation 2014; 17: 515–550.
• Sivanesan, E, Bicket, M, Cohen, S (2019). Retrospective analysis of complications associated with dorsal root ganglion stimulation for pain relief in the FDA MAUDE database. Reg Anesth Pain Med 44(1): 100-106. 
• Al-Kaisy, A, Van Buyten, JP, Smet, I, Palmisani, S, Pang, D, Smith, T Sustained effectiveness of 10 kHz high-frequency spinal cord stimulation for patients with chronic, low back pain: 24-month results of a prospective multicenter study. Pain Med. (2014). 15 347–54.
• Sdrulla, A, Guan, Y, Raja, S, Spinal cord stimulation: clinical efficacy and potential mechanisms. Pain Practice. (November 2018), 18 (8) 1048-67.

CONTACT US

If you have questions about this communication, please contact the Division of Industry and Consumer Education (DICE) at DICE@FDA.HHS.GOV, 800-638-2041, or 301-796-7100.