脊髓静脉高压动物模型的构建和评价

发布时间：2019-02-23 14:02

【摘要】： 目的:构建一种可靠性和重复性较高的脊髓静脉高压动物模型。动态观察脊髓静脉高压模型的MRI变化规律,确定MRI异常信号演变过程及其特征。研究模型脊髓组织大体、细胞结构变化,了解脊髓组织形态学演变规律。方法:新西兰白兔总数22只,18只为模型组,4只对照组。模型制作方法如下:行左肾动静脉端侧吻合术,构建动静脉瘘。结扎左肾动静脉的肾门端,在左右肾静脉之间结扎下腔静脉的近心端,在降结肠静脉以近结扎下腔静脉的远心端,使左肾动脉中的血经动静脉瘘进入到下腔静脉中,再经腰静脉逆流到椎旁静脉丛中,造成脊柱脊髓周围静脉高压环境,希望动脉化的血返流入硬膜内的髓周静脉丛,造成脊髓静脉高压。对照组动物不构建动静脉瘘,其中2只按照模型制作的方法打开腹腔,暴露左肾动静脉,但不行动静脉吻合,待到正常构建模型所需时间后重新关闭腹腔,了解动物能否耐受本方法打击;余下2只作为正常对照。模型术后分成三组,急性期组(3天内)、亚急性期组(3天—3周)、慢性期组(大于3周)。术后1天、3天、1周、2周及以后每周均评价模型的脊髓功能。从各组中随机抽出2只模型了解瘘口通畅情况;再行脊髓MRI检查,观察MRI异常信号和信号部位及变化范围;处死模型,取得全脊髓标本肉眼观察病理变化,光镜下观察脊髓神经元细胞、毛细血管及髓鞘等改变。结果:18只模型中,存活13只,死亡5只,对照组全部生存。经DSA检查证实动静脉瘘存在模型有3只,其中2只为急性期组,1只亚急性期组;闭塞3只,1只亚急性期组,2只慢性期组。术后模型后肢的运动、感觉功能均有所减退,不同时间段表现有差异。脊髓MRI上可见脊髓有增粗变化,T2WI可见髓内有高信号水肿样改变,以胸腰段脊髓最明显,不同时间段脊髓损伤的范围存在差别。脊髓肉眼观察可见脊髓肿胀,光镜下见脊髓神经元细胞变性凋亡、毛细血管充血扩张及神经胶质脱髓鞘样改变。结论:通过该方法首次建立了很好模拟人类脊髓静脉高压病理生理过程的动物模型;模型可靠性和重复性较高,能够满足科研需求,为进一步研究静脉高压性脊髓血管病提供对象;模型的长期稳定性还需要进一步改进。
[Abstract]:Objective: to establish an animal model of spinal venous hypertension with high reliability and reproducibility. The MRI changes of spinal venous hypertension model were observed dynamically, and the evolution process and characteristics of abnormal MRI signals were determined. To study the changes of gross and cellular structure of spinal cord and understand the morphological evolution of spinal cord. Methods: the total number of New Zealand white rabbits was 22, 18 were model group and 4 were control group. The model was made as follows: left renal arteriovenous end-to-side anastomosis was performed to construct arteriovenous fistula. The proximal end of the inferior vena cava, between the left and right renal veins, and the distal end of the inferior vena cava ligated by the descending colonic vein, making the blood in the left renal artery flow through the arteriovenous fistula into the inferior vena cava. Through the lumbar vein countercurrent into the paravertebral venous plexus, the spinal cord surrounding the venous hypertension environment, the hope of arterialized blood back to the intradural perimedullary venous plexus, resulting in spinal venous hypertension. In the control group, the arteriovenous fistula was not constructed, 2 of them opened the abdominal cavity according to the method of model making, exposed the left renal arteriovenous, but did not move the vein anastomosis, and then closed the abdominal cavity again after the time required for the normal construction of the model. To understand whether animals can withstand this method of attack; The remaining 2 were used as normal control. The model was divided into three groups: acute group (3 days), subacute phase group (3 days-3 weeks) and chronic phase group (more than 3 weeks). Spinal cord function was evaluated 1 day, 3 day, 1 week, 2 week and every week after operation. Two models were randomly selected from each group to find out the patency of the fistula, and spinal cord MRI was performed to observe the abnormal signal of MRI, the location of the signal and the range of changes. All the spinal cord specimens were sacrificed to observe the pathological changes with naked eyes, and the changes of spinal cord neurons, capillaries and myelin sheath were observed under light microscope. Results: of the 18 models, 13 survived and 5 died, while the control group all survived. There were 3 models of arteriovenous fistula by DSA, including 2 acute group, 1 subacute group, 3 occlusion group, 1 subacute phase group and 2 chronic phase group. The movement and sensory function of the model hind limbs were all decreased after operation, and the performance was different in different time periods. There were thickening changes in spinal cord on MRI and hyperintense edematous changes in spinal cord on T2WI. The most obvious changes were thoracolumbar spinal cord and the range of spinal cord injury was different at different time points. The swelling of spinal cord was observed with naked eyes, and the degeneration and apoptosis of neurons, capillary hyperemia and glial demyelination were observed under light microscope. Conclusion: the animal model of the pathophysiological process of human spinal venous hypertension was established by this method for the first time. The model has high reliability and reproducibility, which can meet the needs of scientific research and provide an object for further study of venous hypertension myelopathy, and the long-term stability of the model needs to be further improved.
【学位授予单位】：同济大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R-332;R651

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