Establishment of an acute ventral closed spinal cord injury model

Objective. Acute closing spinal cord injury (SCI) is getting more common in clinic while no ideal animal model has been established. Here, we firstly established a new model by ventral violence and examined its neural functional and pathological changes. Methods. A self-designed impinger which coup momentum could be regulated by weight × height (CM). 92 adult male rats were divided into 4 groups: group A (CM: 350 g × 28 cm), group B (CM: 280 g × 28 cm), group C (CM: 210 g × 28 cm) and group D (CM: 0 g × 28 cm). Animal model was made by free falling method at anterior border of T11 centrum under inferior sober state. Complications and mortality were observed. Basso, Beattie and Bresnahan (BBB) score was recorded postoperatively. Morphology and pathological changes of SCI were examined. Results. Coup momentum could be regulated precisely. There were significant differences in BBB scores not only between experimental group and control group but also among 3 experimental groups. In group A and B, contusion, hematoma, subarachnoid hemorrhage appeared at 1-6 hours after injury. Edema was obvious and inflammatory cells were infiltrated at 6-48 hours. Cicatricial contracture and porosis formed at week 3, while group C only showed sporadic punctate hemorrhage. Glial fibrillary acidic protein (GFAP) expression in group B changed dynamically compared with group D. Multiple complications presented in experimental groups. The mortality among groups had significant differences. Conclusion. A novel acute SCI animal model was set up by shape-suitable impinger in simple procedure. At meantime, neural function deficiency, pathological changes and mortality were consistent with severity controlled by coup momentum.