适合MRI研究的羊颈髓压迫损伤模型的制作

目的 探讨建立一种新的适合MRI研究的羊颈髓压迫损伤模型.方法 健康山羊10只,体重20～25 kg,随机分为实验组和对照组.手术显露左侧颈2-3椎间孔,将自制的导管球囊通过椎间孔插入硬膜外腔,达颈2-3椎间盘水平.实验组术后第10天经导管缓慢注射生理盐水0.2 ml使球囊膨胀.持续压迫40天.对照组不注水.利用MR、运动功能评分和病理学检查对模型进行评价.结果 置入的球囊位于脊髓的左前方.球囊未注水时,球囊所在部位蛛网膜下腔变窄,脊髓没有明显受压.注水0.2 ml后,球囊呈椭圆形,脊髓受压变扁.所有MR图像显示清楚,没有明显伪影.实验组运动功能评分下降,病理学检查示神经细胞和神经纤维肿胀、变性、坏死.结论 采用经颈椎椎间孔置入导管球囊制作羊颈髓压迫损伤模型,压迫程度、压迫速度和持续时间可控,保留了椎管的完整性,能获得较满意的MR图像.

Establishment of a goat cervical spinal cord compression injury model suitable for MRI research

Objective To establish a new cervical spinal cord compression injury model suitable for MRI research with goat.Methods Ten goats weighting 20-25 kg were randomly divided into two groups:compression group and control group.A balloon catheter was inserted into the epidural space via the left intervertabral foraman between C_2 and C_3 for each goat.The balloon was positioned at the level of intervertabral space between C_2 and C_3.In compression group,the balloon was inflated by slow injection of 0.2 ml of saline 10 days after operation and remained for 40 days.In control group,the bal- loon was not inflated.Goats were evaluated with MRI,locomotor rating score and pathology.Results The balloon was lo- cated in the lateral-ventral side of the spinal cord.Before the balloon was inflated,the subarachnoid space at the level of C_(2-3) became narrow and the spinal cord was not compressed.In compression group,the balloon became oval and the spinal cord was moderately compressed after the balloon was inflated.All of the MR images were clear without apparent distortion.In compressed group,the locomotor rating scores decreased.Histopathologically,swelling and degeneration of axons and neu- rons could be seen.Conclusion It is feasible to establish a goat cervical spinal cord compression injury model with balloon catheter via interspinal foraman.The degree,speed and duration of compression are under control.The column keeps intact and satisfactory MR images can be achieved.