No Benefit, High Complication Rate With Spinal Cord Stim for Pain?

Use of spinal cord stimulation (SCM) is not associated with reduction in opioid use or nonpharmacologic pain intervention at 2 years, compared to conventional medical management (CMM), and is associated with higher costs and complications, new research suggests. However, at least one expert says the study has shortcomings.

In the retrospective study, researchers compared over 7500 matched patients who had received either SCM or CMM and found that during the first 12 months, those treated with SCS had higher odds of long-term opioid use but were less likely to undergo procedures such as corticosteroid injections, radiofrequency ablation, and spinal surgery. During the second year, there was no significant difference between the groups.

During the 2-year study, close to 20% of those treated with SCS had SCS-related complications, and a little over a fifth underwent device revisions and/or removals. Total costs of care were dramatically higher for SCS than for CMM during the first year but were similar during the second year.

“Our findings suggest that spinal cord stimulators add high cost and have significant risk to patients; these devices are unlikely to provide significant pain relief to patients suffering from chronic pain,” lead author Sanket S. Dhruva, MD, MHS, assistant professor of medicine, University of California, San Francisco, School of Medicine, told Medscape Medical News.

“The clinical implication is that physicians should use guideline-based nonpharmacologic therapy as first-line treatment for pain and follow that, as needed, with carefully selected pharmacologic therapies and treat concurrent conductions, including anxiety and depression,” Dhruva said.

The study was published online November 28 in JAMA Neurology.

Commonly Used

“We know that SCSs are increasingly commonly used in clinical practice and have even been suggested as a device-based alternative to opioids for patients with chronic pain,” Dhruva said.

“However, the current evidence base for SCSs includes primarily small studies, and there are few independent, large, real-world evaluations; and thus, we aimed to conduct one of the most rigorous studies possible outside of a prospective randomized, double-blind, placebo procedure–controlled trial.”

The researchers turned to longitudinal medical and pharmacy claims from Medicare Advantage enrollees drawn from Optum Labs Data Warehouse (February 1, 2021, to August 31, 2022).

They included in their study patients (n = 7560; mean [SD] age, 63.5 [12.5] years; 40.7% men; 59.3% women; 77.9% White; 11.9% Black; 6.4% Hispanic; and 0.7% Asian) with incident diagnosis codes for failed back surgery syndrome, complex regional pain syndrome, chronic pain syndrome, and other chronic postsurgical back and extremity pain.

The study utilized a 1:5 propensity-matched retrospective design (n = 1260 in the SCS cohort and 6300 in the CMM cohort). SCS patients had to have received a permanent, rather than a trial, implant. CMM consisted of pain medications, spine surgery, radiofrequency ablation, epidural and facet corticosteroid injections, and conservative nonpharmacologic therapies (physical therapy, chiropractic, and acupuncture).

Long-term opioid use and epidural and facet corticosteroid injection use from 1–12 and 13–24 months after the index date (primary outcomes) were “surrogates” for primary long-term pain treatment modalities.

Other outcomes included medications and treatments (long-acting opioid use; radiofrequency ablations; new spine surgeries; and filling prescriptions for nonsteroidal anti-inflammatory drugs, systemic corticosteroids, antidepressants, gabapentinoids, and benzodiazepines); healthcare utilization, total costs of care, postprocedural complications; and SCS removal and revision.

Efficacy “Overestimated”

At baseline, 79% of the patients who were treated with SCS also received opioids, and 15.4% were receiving rehabilitative therapies.

During the first year, patients treated with SCSs had higher odds of long-term opioid use but lower odds of utilizing other procedures and medications. During the second year, there was no difference between the groups in long-term opioid use or utilization of other procedures and medications.

Table. Adjusted Odds Ratios for SCS vs CMM (95% CI)

Outcome	1–12 months	13–24 months
Long-term opioid use	1.14 (1.01 – 1.29)	1.06 (0 .94 – 1.20)
Epidural/facet corticosteroid injections	0.44 (0.39 – 0.51)	1.00 (0.87 – 1.14)
Radiofrequency ablation	0.57 (0.44 – 0.72)	0.84 (0.66 – 1.09)
Spine surgery	0.72 (0.61 – 0.85	0.91 (0.75 – 1.09)

 

Of the patients treated with SCS, 17.9% experienced SCS-related complications (including breakdown, displacement, other mechanical complications, and infection of the lead and/or generator) within 2 years; 22.1% underwent device revisions and/or removal, and of these, one tenth of cases were not associated with a complication, “suggesting a lack of effectiveness,” the authors write.

Total costs of care in the first year were $39,000 higher with SCS than with CMM, although costs were similar between the modalities in the second year.

“I think that our findings suggest SCSs are not effective at reducing pain at a sufficient level that patients reduce use of opioids,” Dhruva commented. “This could be related to the fact that the clinical trials for SCS — when they have been conducted — have very infrequently used a placebo procedure, and thus, efficacy is likely to be overestimated.”

“Multiple Issues”

Commenting for Medscape Medical News, Joshua M. Rosenow, MD, director of functional neurosurgery and professor of neurosurgery, neurology, and physical medicine and rehabilitation, Northwestern Medicine, Chicago, Illinois, said that the study has “multiple issues.”

“It is generally accepted that SCS therapy increases healthcare costs in the short term due to the cost of surgery and the device itself.” But other studies have “shown that cost neutrality typically takes about 2.5 years to achieve, so by stopping short of that time point, it is not surprising that SCS patients had higher healthcare costs,” said Rosenow, who was not involved in the research.

Multiple peer-reviewed studies have shown that patients who successfully undergo SCS “are overall able to significantly decrease their opioid use,” and in this study, a closer look at the data “shows that in the first year, the SCS patients were more likely to be using high-dose opioids but were no more likely to be using high-dose opioids in the second year…contradicting the dire conclusion of the study that SCS has no effect on opioid use.”

In addition, the study “has insufficient detail to understand for what pain condition these individuals were using opioids…. Likewise, we do not know if the interventional pain procedures and spinal surgery these people received were for the same pain indication as the SCS was targeting,” Rosenow added.

Furthermore, he noted that the study “does not include functional outcomes…. What this study cannot show us is whether the people who received SCS were more functional with the device as one component of their pain treatment.”

SCS “has decades of peer-reviewed evidence attesting to its effectiveness in reducing pain and improving function across multiple chronic pain syndromes,” Rosenow concluded. “As leaders in the field, it is incumbent upon us to continue to educate those physicians using this therapy on appropriate patient selection, safety, proper technique, and complication avoidance and management.”

Dhruva has received grants from Arnold Ventures; research funding from the Greenwall Foundation, the Department of Veterans Affairs, the National Evaluation System for Health Technology Coordinating Center, the US Food and Drug Administration, and the National Institute for Health Care Management; and has served on the Institute for Clinical and Economic Review California Technology Assessment Forum. The other authors’ relevant financial relationships are listed on the original article. Rosenow has consulting agreements with Boston Scientific Neuromodulation, Stryker, and AIM Medical Robotics.

JAMA Neurol. Published online November 28, 2022. Abstract

Batya Swift Yasgur, MA, LSW, is a freelance writer with a counseling practice in Teaneck, NJ. She is a regular contributor to numerous medical publications, including Medscape and WebMD, and is the author of several consumer-oriented health books as well as Behind the Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters who told her their story).

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