Abstract:Objective: This study aimed to evaluate the functionality, long-term safety, and histocompatibility of a newly developed domestic implantable spinal cord stimulation system (SCS). Methods: Fifteen small Tailed Han Sheep were selected, with nine undergoing SCS implantation under X-ray fluoroscopic guidance for a short duration of 2 weeks (Group S). The remaining six were implanted with puncture electrodes, surgical electrodes, and pulse generators and monitored for an extended period of 26 weeks (Group L). Key observations included behavioral responses, laboratory examinations encompassing routine blood test, liver and kidney function tests, coagulation levels, device electrical impedance, high and low-frequency stimulation effects, and potential electrode displacements. In group S and group L, gross anatomy and hematoxylin-eosin staining of the tissues around the electrodes and other tissues were taken at 2 weeks and 26 weeks postoperatively, respectively, for pathological examination. Results: Postoperative behavioral patterns remained consistent for sheep, irrespective of whether they had short-term or long-term electrode implantations. Laboratory examinations for both groups indicated all monitored parameters, including white blood cell count, platelets, red blood cell count, liver and kidney functions, and coagulation function, remained within standard limits. Equipment impedance values were stable, showcasing consistent performance. No displacement of the implanted electrodes was observed. The stimulated spinal cord sections did not exhibit significant pathological changes when compared to their unstimulated counterparts, showing no signs of cell death, swelling, reduced blood flow, or inflammation. Conclusion: The indigenous implantable SCS system showcases robust functionality, biocompatibility, and safety during prolonged implantation, making it a viable option for clinical application.
