Spinal Cord Stimulators for Chronic Back Pain Win FDA Approval

On May 16, 2023, the U.S. Food and Drug Administration (FDA) approved spinal cord stimulation (SCS) devices from the pharmaceutical company Abbott to treat chronic back pain in people who have not had or are not eligible to receive back surgery, per a press release from Abbott. Approval was granted after a six-month study of 200 participants showed that spinal cord stimulation provided significant relief and improvements in pain, function, quality of life, and mental health.Those enrolled in the trial had experienced an average of nearly 13 years of disabling chronic back pain. Participants were not eligible for corrective back operations because they were either medically frail or they had numerous degenerative changes in their spine, none of which were severe enough to qualify for corrective surgery but are nonetheless causing significant symptoms.

After half a year, 85 percent of those implanted with Abbott’s SCS devices achieved significant back pain reduction, compared with only 7 percent receiving conservative medical management. On average, people who received SCS therapy experienced about a 70 percent reduction in pain.

“Historically, people who have no options for corrective surgery to address their chronic back pain are usually treated with combinations of therapies: physical therapy and chiropractic care, injections, and pain relievers,” says Allen Burton, MD, the divisional vice president and chief medical officer of Abbott’s neuromodulation business. “However, these options are not effective for a significant subset of people who previously did not have other therapies available, while causing the treatment journey to feel complicated and uncertain for others. People who suffer from chronic back pain — and do not fit the typical surgical criteria — tend to forgo future treatment, ultimately resign themselves to living with debilitating chronic pain.”

The U.S. Pain Foundation estimates that about 50 million Americans live with chronic back pain.

While many people experience chronic back pain as result of arthritis, spinal stenosis, or disk problems, the cause of chronic back pain can sometimes be hard to pinpoint, often making it difficult to identify a clear treatment plan. Dr. Burton notes that doctors may recommend more conservative approaches to managing chronic back pain through exercises, physical therapy or chiropractic care, pharmaceutical management, and injections. However, even a combination of these conservative measures may not be enough to provide relief from chronic pain for some people.

Advancement of an Old Concept

While the use of electrical stimulation to relieve pain may seem modern, research indicates the idea dates back to ancient Rome, when physician Scribonius Largus found that gout pain could be relieved by contact with the torpedo fish (also known as an electric ray), which can stun other animals with a natural electrical charge.

It wasn’t until 1968, however, that the Medtronic company introduced the first commercially available spinal cord stimulator.

Abbott’s latest SCS devices use proprietary BurstDR stimulation technology, the first to use pulses of mild electrical energy to mimic the body’s normal electrical signals, masking those that signal pain as they travel to the brain.

Michael Leong, MD, a pain specialist at the Stanford Cancer Center in California, who was not involved in Abbott research, notes that the pulse systems are different from previous spine stimulation technologies, in that the patient does not feel the stimulation.

“Other previous systems used something called ‘tonic stimulation,’ which created a tingling that patients could feel,” says Dr. Leong. “With these newer waveforms, you can't feel the sensation.”

Leong adds that significant reduction of physical pain as provided through this type of stimulation can also help reduce emotional symptoms.

“A lot of people with chronic pain develop symptoms of depression and anxiety,” he says. “If a device can ease not just physical pain but the emotional pain that goes along with it, that’s a huge benefit.”

As mental and physical health improve, so do quality of life and productivity.

How the Device Is Implanted

People with chronic back pain who are interested may first trial the technology for 7 to 10 days, and if it feels beneficial, the device can then be implanted. Dr. Burton compares the implanting process with getting a heart pacemaker. It stays with the patient so it can treat the pain continuously.

The procedure is not very intrusive, according to Leong.

“The devices are very, very tiny,” he says. “They used to be the size of a hockey puck, but now they’re the size of batteries in our iPhones.”

The device is often positioned just underneath the skin of the back or the buttock. Thin wires from the device are placed in the spinal column near the nerves which carry pain signals. The electronics send out continuous electrical pulses that disrupt pain signals before they can reach the brain.

Typical implantation time for an SCS device takes between one to two hours. These procedures are usually performed on an outpatient or overnight stay-basis.

Potential Limitations of Spinal Cord Stimulation

This latest FDA stamp of approval for Abbott covers all the devices the company current offers in the United States, including its Proclaim Plus implant (with a battery that lasts up to 10 years) and its rechargeable Eterna system.

Although these devices are rapidly gaining federal approval, Mark Queralt, MD, the director of the Musculoskeletal Institute and back and neck pain clinical director with Dell Medical School at the University of Texas in Austin, urges consumers to be cautious and consider all the evidence about these stimulators.

This latest study results by Abbott are limited, he says, because they reflect responses from just 200 people. Results from 2,000 patients or more would provide a better sense if this technology provides benefit in a real-world scenario, he says.

Queralt questions the value of this type of therapy based on research suggesting that spinal cord stimulation does not result in a lower level of opioid use, pain injections, or spine surgery. He also warns about the price of such therapy, which according to industry analysis can cost $39,000 more in the first year than conventional medical therapy.

“People who have had chronic pain for years are desperate for anything. Hope is a powerful motivator, and this gives them hope,” he says. “I’m not overly optimistic about this technology. Look at all the evidence. Time will tell on this.”

Leong recommends that those with chronic back pain should “in good conscience” try more conservative approaches first, such as physical therapy and medications. “But if these don't work, and if you don't think you're going to have some kind of, or need, corrective surgery, this can be a great option,” he says.