Animal Feasibility Study of a Novel Spinal Cord Stimulation Multicolumn Lead (Heron Lead)

Abstract

Background: Currently available spinal cord stimulation paddle leads require a laminectomy, limiting the types of clinicians who can implant and increasing the risk of complications. Recently, WISE S.r.l. designed a prototype multicolumn lead named the Heron® lead that can be implanted percutaneously. The purpose of the study was to examine the efficiency of placing a paddle lead percutaneously. Methods: Ten sheep were assigned to either the Heron lead group (n = 7) or the control group (n = 3). The sheep were observed for 13 weeks after implantation. Neurological and clinical examinations were conducted prior to surgery and then during the follow-up period. The implantation sites were evaluated through macroscopic observations during the article explantation and the lead migration was evaluated by comparing the article positioning at the surgery, four weeks after the surgery and at the explantation day through fluoroscope images. A qualitative comparison was made between the results collected with the test article and the control article. Results: Observations at the surgical sites indicate that test animals appeared to have less swelling around the surgical wound than control ones in the first 14 days, but no impact on wound healing was noticed. Additionally, no clear difference was observed in pain scores between the two groups, with observations tending to show that the maximum pain was occurring later in the test group with respect to the control group. General clinical observations showed no major difference between the two groups, and determined clinical abnormalities were not directly related to the procedure. Lastly, neurological deficits frequency decreased from the first to last animal operated, regardless of their test or control status. Conclusions: Our study concluded that the Heron lead is safe to implant, with a safety profile similar to the control article. Additionally, we conclude that the Heron lead is effective in reducing lead migration events.