Safety of intramedullary Schwann cell transplantation for postrehabilitation spinal cord injuries: 2-year follow-up of 33 cases

Object. Many experimental studies on spinal cord injuries (SCIs) support behavioral improvement after Schwann cell treatment. This study was conducted to evaluate safety issues 2 years after intramedullary Schwann cell transplantation in 33 consecutively selected patients with SCI. Methods. Of 356 patients with SCIs who had completed at least 6 months of a conventional rehabilitation program and who were screened for the study criteria, 33 were enrolled. After giving their informed consent, they volunteered for participation. They underwent sural nerve harvesting and intramedullary injection of a processed Schwann cell solution. Outcome assessments included a general health questionnaire, neurological examination, and functional recordings in terms of American Spinal Injury Association (ASIA) and Functional Independence Measure scoring, which were documented by independent observers. There were 24 patients with thoracic and 9 with cervical injuries. Sixteen patients were categorized in ASIA Grade A, and the 17 remaining participants had ASIA Grade B. Results. There were no cases of deep infection, and the follow-up MR imaging studies obtained at 2 years did not reveal any deformity related to the procedure. There was no case of permanent neurological worsening or any infectious or viral complications. No new increment in syrinx size or abnormal tissue and/or tumor formation were observed on contrast-enhanced MR imaging studies performed 2 years after the treatment. Conclusions. Preliminary results, especially in terms of safety, seem to be promising, paving the way for future cell therapy trials. (DOI: 10.3171/2011.6.SPINE10917)