Toumpoulis Ioannis K, Papakostas John C, Matsagas Miltiadis I, Malamou-Mitsi Vassiliki D, Pappa Lina S, Drossos George E, Derose Joseph J, Anagnostopoulos Constantine E
Department of Cardiothoracic Surgery, School of Medicine, University of Ioannina, Ioannina, Greece.
J Thorac Cardiovasc Surg. 2004 Nov;128(5):724-30. doi: 10.1016/j.jtcvs.2004.06.031.
We previously showed that ischemic preconditioning significantly reduced spinal cord injury caused by 35-minute aortic occlusion. In this study we investigated the effect of ischemic preconditioning on spinal cord injury after 45-minute aortic occlusion.
Thirty-two pigs were divided as follows: group 1 (n = 6) underwent sham operation, group 2 (n = 6) underwent 20 minutes of aortic occlusion, group 3 (n = 6) underwent 45 minutes of occlusion, group 4 (n = 6) underwent 20 minutes of occlusion and 48 hours later underwent an additional 45 minutes, and group 5 (n = 8) underwent 20 minutes of occlusion and 80 minutes later underwent an additional 45 minutes. Aortic occlusion was accomplished with two balloon occlusion catheters placed fluoroscopically after the origin of the left subclavian artery and at the aortic bifurcation. Neurologic evaluation was by Tarlov score. The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin-eosin staining. The number of neurons was counted, and the inflammation was scored (0-4). Statistical analysis was by Kruskal-Wallis and 1-way analysis of variance tests.
Group 5 (early ischemic preconditioning) had better Tarlov scores than group 3 ( P < .001) and group 4 (late ischemic preconditioning, P < .001). The histologic changes were proportional to the Tarlov scores, with the least histologic damage in the animals of group 5 relative to group 3 (number of neurons P < .001, inflammation P = .004) and group 4 (number of neurons P < .001, inflammation P = .006).
Early ischemic preconditioning is superior to late ischemic preconditioning in reducing spinal cord injury caused by the extreme ischemia of 45 minutes of descending thoracic aortic occlusion.
我们之前的研究表明，缺血预处理能显著减轻由35分钟主动脉阻断所导致的脊髓损伤。在本研究中，我们调查了缺血预处理对45分钟主动脉阻断后脊髓损伤的影响。
32头猪被分为以下几组：第1组（n = 6）接受假手术；第2组（n = 6）接受20分钟的主动脉阻断；第3组（n = 6）接受45分钟的阻断；第4组（n = 6）接受20分钟的阻断，48小时后再接受45分钟的阻断；第5组（n = 8）接受20分钟的阻断，80分钟后再接受45分钟的阻断。通过在左锁骨下动脉起始处和主动脉分叉处经荧光透视放置两个球囊阻断导管来实现主动脉阻断。通过塔尔洛夫评分进行神经学评估。在120小时时采集下胸段和腰段脊髓，并用苏木精-伊红染色进行组织学检查。对神经元数量进行计数，并对炎症进行评分（0 - 4分）。采用克鲁斯卡尔-沃利斯检验和单因素方差分析进行统计分析。
第5组（早期缺血预处理）的塔尔洛夫评分优于第3组（P < .001）和第4组（晚期缺血预处理，P < .001）。组织学变化与塔尔洛夫评分成比例，与第3组相比，第5组动物的组织学损伤最小（神经元数量P < .001，炎症P = .004），与第4组相比也是如此（神经元数量P < .001，炎症P = .006）。
在减轻由胸降主动脉45分钟极端缺血所导致的脊髓损伤方面，早期缺血预处理优于晚期缺血预处理。
