Comparison of intramedullary transplantation of olfactory ensheathing cell for patients with chronic complete spinal cord injury worldwide

Traumatic spinal cord injury (tSCI) remains a major clinical challenge. Cell transplantation brings a glimmer of light, among them olfactory ensheathing cells (OECs) have shown some neurorestorative effect. Due to the results of each group lack basic consistency, many technical details are believed to affect the overall outcome. We compare the clinical outcome of intramedullary transplant of olfactory ensheathing cells for patients with spinal cord injury at multi-centers worldwide, and to explore the potential standardized transplantation that suits for the clinical requirements. Here, we used the Pubmed and CNKI databases to search online the literatures published in the last 20 years for the clinical studies/trials of OECs for chronic spinal cord injury in the representative clinical center. The results of these representative clinical treatment centers were searched and analyzed. The parameters which may affect the effect including the concentration of cells, the total number of cells, the choice of incision, the site of transplantation, the number of transplantation sites, the advantages and disadvantages of transplantation equipment, and postoperative management, were compared carefully to clarify its impact on the clinical results. In these literatures, 2 Chinese centers, 1 Australian center and 1 European center were selected for intraspinal transplantation. The reason of different results may be due to the excessive injection times and/or the excessive total injection volume. Cell implant to the spinal cord parenchyma is effective for restoring neurological functions, but improper procedures may lead to ineffective results. Concise surgery appears to be more suitable for clinical application than ostensibly precise and complex injection procedures. Sufficient rehabilitation training is surely necessary for the integration of motor recovery after cell transplantation.