Chronic midline low back pain is the number one reason for disability in the United States despite the prolific use of medical and surgical interventions. Notwithstanding the widespread use of epidural spinal cord stimulators (SCS), there remains a large portion of the population with inadequate pain control thought to be due to the limited volume of stimulated neural tissue. Intradural SCS represents an underexplored alternative strategy with the potential to improve selectivity, power efficiency, and efficacy. This group has studied and carried out development of an intradural form of SCS. Herein we present the findings of in vivo testing of a prototype intradural SCS in a porcine model.
Six female juvenile pigs underwent surgical investigation. One control animal underwent a laminectomy only, while the five other animals had implantation of an intradural SCS prototype. One of the prototypes was fully wired to enable acute stimulation and concurrent EMG recordings. All animals underwent terminal surgery 3 months post-implantation, with harvesting of the spinal column. Imaging (microCT) and histopathological examinations were subsequently performed.
All animals survived implantation without evidence of neurological deficits or infection. Post-mortem imaging and histopathological examination of the spinal column revealed no evidence of spinal cord damage, CSF fistula formation, abnormal bony overgrowth, or dural defect. Viable dura was present between the intra- and extra-dural plates of the device. EMG recordings revealed evoked motor units from the stimulator.
Chronically implanted intradural device in the porcine model demonstrated safety and feasibility for translation into humans.

Copyright © 2020. Published by Elsevier Inc.