Computed tomography-guided injection of muscle-derived mesenchimal stem cells in the intervertebral disc of dogs affected by natural disc degeneration: clinical safety and intervertebral disc imaging assessment

Introduction/Purpose:
Pre-clinical randomized controlled animal trials have been conducted to evaluate the effects of mesenchymal stem cell (MSCs) transplantation on intervertebral disc (IVD) degeneration. According to their histological results and to imaging assessment of the IVD, intradiscal injection of MSCs is effective, arresting or slowing IVDD process, and is associated with a low complication rate. Few of these studies have been conducted on canine artificially degenerated IVD, using bone marrow or adipose-derived MSCs. Therefore a systematic study on naturally degenerated IVD using MSCs obtained from autologous muscular tissue in dogs is still lacking. The aims of this study were to evaluate the clinical effects of intradiscal injection of muscle-derived MSCs and its effects on imaging features of the intervertebral disc.
Methods:
Eight experimental dogs were randomly included with the approval of the University’s Animal Care and Use Committee. The final inclusion criteria were the presence of naturally degenerated lumbosacral IVD detected on low-field magnetic resonance (MRI) images and the obtaining of 3 x 106 autologous muscle-derived MSCs.
A computed tomography (CT) and MRI examination was performed before and 2 months after the procedure and 13 imaging parameters were assessed. Mesenchymal stem cells diluted in 0,2 ml of FRS Hypothermosol were injected in the lumbosacral IVD under CT-guidance. Clinical examinations were performed regularly during 1 month after the procedure.
Results:
Six dogs met the inclusion criteria. The remaining 2 dogs did not undergo intradiscal injections, but were used as control group. No major or minor complications were reported during the procedure. No abnormalities were noticed during the clinical examinations. No statistically significant variations of IVD imaging features were noticed before and after the injections.
Discussion/Conclusions:
Intradiscal injection of muscle-derived MSCs is clinically safe and it is not associated with any progression of the IVD degeneration, detected by CT or low-field MRI imaging. Further studies are needed to assess its efficacy as treatment for the canine natural IVD degeneration.