Implantable Device for Chronic Pain Reduced Disability Scores by 27%

Results of a study about an implantable device for chronic pain relief showed it reduced disability by about 27%, according to patient-reported outcomes about this nondrug pain treatment. Data about the device, called dorsal root ganglion (DRG) neurostimulation therapy, was presented recently at the annual meeting of the American Society of Anesthesiologists.

DRG therapy has been used in the treatment of complex regional pain syndrome and peripheral nerve injuries. The DRG is a cluster of neurons located on both sides of each vertebra, and stimulation targets pain sensations before they reach the spinal cord. DRG is different than spinal cord stimulation, because it can avoid unnecessary stimulation of nerve fibers that come from nonpainful areas.

In DRG therapy, the device is implanted under the skin in the lower back and sends small electronic pulses through a wire placed near the DRG that is connected to the nerve associated with the pain. The pulses replace the pain with a different sensation, such as tingling or numbness. The level of current provided by the device is programmed by a physician anesthesiologist or other pain specialist based on the patient's pain.

The FDA approved DRG therapy in 2016. Last month, Abbott, which sells the device, announced that it received a national coverage determination for its device from Aetna. Chronic pain conditions, such as neuropathies, are thought to affect about 100 million people in the United States. Efforts to manage chronic pain have come under scrutiny because of the rising toll of deaths from prescription opioids and illicit synthetic opioids.

The study involved 67 patients with chronic pain in the lower limbs and the lower back and were followed for 3 to 18 months. Seventeen patients had the device for more than a year.

Before implantation of the DRG device, most participants described their pain as 8 on a scale of 1 to 10 (with 10 being the worst pain imaginable).

After followup, the median pain score fell to 5, a decrease of 33%. Patients reported a 27% decrease in disability, or patient-reported limitations to daily living, due to pain, and 94% of patients reported the treatment was beneficial.

Five patients had to have the wires re-implanted, 2 had them removed after they were infected, and 1 had the device removed due to a complication with the foot.

Reference

McCarthy RJ, Lubenow TR. Dorsal root ganglion stimulation for chronic pain. Anesthesiology 2018; October 13-17, 2018 San Francisco, CA. Abstract A2301.