A Bayesian Network Analysis of the Efficacy of Scaffolds and Stem Cells in Spinal Cord Injury Treatment.

Backgrond: Novel scaffolds and stem cells are alternatives for the treatment of spinal cord injury (SCI), which causes life-long disability. However, there is a lack of synthesized evidence comparing different therapies.

Aim: To examine the efficacy of various treatments in achieving locomotor recovery in SCI animals. The PubMed, Scopus and Web of Science databases were searched from inception to 21st May 2021.

Methods: The data were extracted by one investigator under the surveillance of a referee according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement and stored in Microsoft Excel. All data were analysed using Bayesian network analysis with a consistency model. The selection was performed in strict accordance with the participant, intervention, comparison, outcome and study (PICOS) principle, as specifically stated in the methods section.

Results: A total of 387 eligible studies involving 11169 animals subjected to 5 different treatments were evaluated. Compared to placebo or no treatment, scaffolds (mean difference (MD), 2.04; 95% credible interval (CrI): 1.58 to 2.50), exosomes (MD, 3.46; 95% CrI: 3.07 to 3.86), stem cells (MD, 4.18; 95% CrI: 3.28 to 5.07), scaffolds in conjunction with stem cells (MD, 5.26; 95% CrI: 4.62 to 5.89), and scaffolds in conjunction with non-cell agents (MD, 4.88; 95% CrI: 4.21 to 5.54) led to significant recovery of locomotor function in SCI animals. No significant difference in the locomotor function score was observed between animals treated with stem cells and those treated with exosomes (MD, 0.71; 95% CrI: -0.25 to 3.05), between animals treated with scaffolds in conjunction with stem cells and those treated with scaffolds in conjunction with non-cell agents (MD, -0.38; 95% CrI: -1.24 to 0.49), or between animals treated with scaffolds in conjunction with non-cell agents and those treated with stem cells (MD, 0.71; 95% CrI: - 0.38 to 1.80).

Conclusion: Significant differences in the efficacy of various therapies in SCI animals were observed, and transplantation of scaffolds in conjunction with non-cell agents, scaffolds in conjunction with stem cells, and stem cells should be considered over transplantation of exosomes or scaffolds alone. Even though transplantation of scaffolds alone promoted locomotor function recovery in SCI animals, its use should be discouraged.