Long⁃term stability evaluation of syringomyelia rats

Abstract

Objective To investigate the long⁃term stability of syringomyelia (SM) rat model constructed by epidural compression. Methods A total of 35 Sprague⁃Danley (SD) rats were randomly divided into sham surgery group (n=9), short⁃term group (n=6) and long⁃term group (n=20). The central spinal canal was blocked by epidural compression to induce SM in rats. Basso⁃Beattie⁃Bresnahan score (BBB) was used to evaluate lower limb motor function before surgery and at 3, 6, 9 and 12 months after surgery. The morphological changes of SM were evaluated by MRI and HE staining at 2 and 12 months after surgery. Results At 2 and 12 months after surgery, MRI showed 80% (16/20) and 85% (17/20) rats in long⁃term group had SM. Compared with 2 months after surgery, the ratio of the maximum cavity diameter to the diameter of spinal cord plane (Z=⁃3.518, P=0.000) and the ratio of the maximum cavity area to the area of spinal cord plane (Z=⁃3.464, P=0.001) increased in long⁃term group at 12 months after surgery. At 2 and 12 months after surgery, the morphology of the spinal cord was normal and there was no cavity in sham surgery group, while the spinal cord cavity was observed in the short⁃term group at 2 months after surgery. At 12 months after surgery, the cavity area of the long⁃term group was not only larger than that of the short⁃term group, but also involved more vertebral segments. There was no significant difference in BBB score between sham surgery group and long⁃term group at different time points before and after surgery (P＞0.05, for all). Conclusions The rat model of SM constructed by epidural compression has high positive rate, good long⁃term stability, and does not affect the motor function of rats.

Keywords

• syringomyelia
• epidural space
• magnetic resonance imaging
• pathology
• disease models animal