A closed-loop spinal cord stimulation (CLSCS) system (Evoke ECAP-Controlled Closed-Loop Spinal Cord Stimulation System; Saluda Medical, Artarmon, NSW, Australia) provided significant relief for participants with chronic pain in 2 clinical studies. The Evoke (NCT02924129) and Avalon (ACTRN12615000713594) studies demonstrated improvements in pain, function, sleep, and quality of life with CLSCS vs control.
In the US Evoke study, at the 3-month point, participants treated with CLSCS vs had statistically superior back and leg pain relief—without increased use of pain medications—with 82.3% of subjects achieving relief greater than or equal to control subjects; 58.1% of subjects experienced greater than or equal to 80% reduction in back and leg pain.
Results at the 18-month point of the Australian Avalon study include 69.4% of patients experiencing more than 80% pain relief; 83.3% experiencing clinically meaningful improvement in quality of life, with disability reduction—72.2% had minimal to moderate disability vs 18.0% of control subjects. More than 2 of 3 patients (67.9%) reduced or eliminated opioid medications.
“Two separate studies of the Evoke System show promising results,” said Steven M. Falowski, MD, director of functional neurosurgery at Neurosurgical Associates of Lancaster in Lancaster, PA “The US Evoke study, the first double-blind randomized regulatory approval study in SCS, demonstrated better rates in pain relief and secondary outcomes for closed-loop compared to control. The Avalon study, an Australian prospective, single-arm study, provides long-term evidence for sustained pain relief with closed-loop. Both studies provide evidence supporting the novel design of the device where ECAPs are measured to monitor therapy delivery in real time. The technology provides an objective measure based on a neurophysiological response to control therapy delivery and provides insight into the mechanism of action.”
This SCS system measures spinal cord response to stimulation via evoked compound action potentials (ECAPs) and adjusts every pulse to maintain activation.
James Geyer, MD, and Paul Cox
Britany Klenofsky, MD, and Huma U. Sheikh, MD
Chia-Chun Chiang, MD, and Juliana VanderPluym, MD, FRCP, FAHS