Toumpoulis Ioannis K, Anagnostopoulos Constantine E, Drossos George E, Malamou-Mitsi Vassiliki D, Pappa Lina S, Katritsis Demosthenes G
Departments of Cardiothoracic Surgery, University Hospital of Ioannina, School of Medicine, Ioannina, Grece.
J Vasc Surg. 2003 Feb;37(2):426-32. doi: 10.1067/mva.2003.1.
Ischemic preconditioning has been found to protect various organs from a subsequent longer ischemic insult. We investigated whether the late phase of ischemic preconditioning reduces spinal cord injury from occlusion of the descending thoracic aorta.
Twenty-four pigs (27 to 30 kg) were randomly divided in four groups: group I (n = 4) underwent a sham operation, group II (n = 4) underwent aortic occlusion for 20 minutes, group III (n = 8) underwent aortic occlusion for 35 minutes, and group IV (n = 8) underwent aortic occlusion for 20 minutes and, 48 hours later, aortic occlusion for 35 minutes. Aortic occlusion was accomplished with two balloon occlusion catheters placed fluoroscopically at T(6) to T(8) above the diaphragm and at the aortic bifurcation. Neurologic evaluation was performed by an independent observer according to Tarlov's scale (0 to 4, with 4 as normal). The lower thoracic and lumbar spinal cords were harvested at 120 hours and examined histologically with hematoxylin and eosin stain. Histologic results (number of neurons and grade of inflammation) were scored 0 to 4 (4, intact spinal cord; 0, no neurons and high inflammation) and were similarly analyzed. Results were expressed as the mean +/- the standard error of the mean, and statistical analysis used the Kruskal-Wallis test.
Group IV had a better neurologic outcome at 24, 48, and 120 hours in comparison with group III (P <.001), although 120 hours after the end of the experiment, the neurologic outcome in group IV was worse than at 24 hours (P =.014). The histologic changes were proportional to the neurologic test scores, with the more severe and extensive gray matter damage in the animals of group III (number of neurons, P <.001; and grade of inflammation, P <.001).
Ischemic preconditioning (late phase, 48 hours after the first occlusion) reduces spinal cord injury after aortic occlusion, as estimated with Tarlov's score and histopathology.
已发现缺血预处理可保护各种器官免受随后更长时间的缺血性损伤。我们研究了缺血预处理的晚期阶段是否能减轻降主动脉闭塞所致的脊髓损伤。
将24头猪（体重27至30千克）随机分为四组：第一组（n = 4）接受假手术，第二组（n = 4）接受主动脉闭塞20分钟，第三组（n = 8）接受主动脉闭塞35分钟，第四组（n = 8）接受主动脉闭塞20分钟，48小时后再接受主动脉闭塞35分钟。通过在透视引导下将两根球囊闭塞导管分别置于膈上T(6)至T(8)以及主动脉分叉处来实现主动脉闭塞。由一名独立观察者根据塔尔洛夫量表（0至4分，4分为正常）进行神经学评估。在120小时时采集胸段下部和腰段脊髓，并用苏木精和伊红染色进行组织学检查。组织学结果（神经元数量和炎症分级）评分为0至4分（4分表示脊髓完整；0分表示无神经元且炎症严重），并进行类似分析。结果以平均值±平均标准误表示，统计分析采用克鲁斯卡尔 - 沃利斯检验。
与第三组相比，第四组在24、48和120小时时的神经学结果更好（P <.001），尽管在实验结束120小时后，第四组的神经学结果比24小时时更差（P =.014）。组织学变化与神经学测试评分成比例，第三组动物的灰质损伤更严重且广泛（神经元数量，P <.001；炎症分级，P <.001）。
根据塔尔洛夫评分和组织病理学评估，缺血预处理（晚期，首次闭塞后48小时）可减轻主动脉闭塞后的脊髓损伤。
