急性脊髓前动脉及双侧椎动脉阻断对颈髓血流量影响的实验研究

An experimental study on ischemic injuries of cervical spinal cord after acute blockade of anterior spinal artery and bilateral vertebral arteries

目的:研究颈部脊髓前动脉及双侧椎动脉阻断对颈髓血流量的影响及其病理学变化。方法:将48只家兔随机分为阻断脊髓前动脉组与阻断脊髓前动脉和双侧椎动脉组,术后6h、24h、72h采用激光多普勒血流测定仪检测颈髓血流灌注量,电镜观察颈髓组织细胞形态学、免疫组化检测神经丝的变化。结果:脊髓前动脉阻断后颈髓血流量下降1/2,随后有所回升,但依然处于低灌注状态;阻断脊髓前动脉和双侧椎动脉后,其血流量下降更为显著,为对照组的1/3,电镜及免疫组化显示两组均出现了缺血性改变,经统计学检验两组每一时相点的血流量和神经丝表达程度均有显著性差异(P<0.05)。结论:颈髓前部血流量除与脊髓前动脉有关外,前根动脉也有一定的作用,临床上各种原因造成脊髓前动脉或根动脉的损伤均可能导致颈髓缺血性损伤。

Objective：To study the effect on the blood supply of cervical spinal cord and its correspondant histopathological changes after acute injuries of anterior spinal artery and bilateral vertebral arteries.Method： Forty-eight rabbits were randomly divided into two groups：anterior spinal arteries were blocked as group Ⅰ, and anterior spinal artery and bilateral vertebral arteries were both blocked as group Ⅱ.Blood flow changes of cervical spinal cord were measured by Laser Doppler Flowmetry（LDF） after 6 hours,24 hours and 72 hours. Cell morphology and expression of neurofilament in the cervical spinal cord were noted by the electron microscope and immunohistochemistry respectively.Result：The blood flow of cervical spinal cord in test group Ⅰ decreased to half of that of its control group after blocking the anterior spinal artery.With the prolonging of isehemic time,the blood flow increased gradually.But it was still far much lower than that of its control group. The blood flow of the cervical spinal cord decreased even more in test group Ⅱ ,which was only one third of its control group＇s.Acute ischemic changes both appeared in the two experimental groups.There were significant differences in blood flow and expression level of neurofilament between the two experiment groups at every time point （P〈0.05）.Conclusion ： Anterior radicular arteries,as well as anterior spinal cord artery, play an important role in blood supply of anterior cervical spinal cord,and any injuries to one of them can undoubtedly result in cervical spinal cord ischemic lesion.