Svensson L G, Von Ritter C M, Groeneveld H T, Rickards E S, Hunter S J, Robinson M F, Hinder R A
Ann Surg. 1986 Jul;204(1):38-47. doi: 10.1097/00000658-198607000-00005.
There is a high incidence of paraplegia associated with thoracic aortic cross-clamping, even when cardiopulmonary bypass or shunts are used. In 56 adult baboons, spinal cord blood flow (SCBF), vascular anatomy, and paraplegia rates were evaluated. Tissue blood flow was measured by radioactive microspheres. Various procedures were used to increase SCBF and to prevent ischemia-reperfusion injury. It was found that the rate of paraplegia was inversely correlated with neural tissue ischemia (SCBF) and directly correlated with reperfusion hyperemia. Two methods completely prevented paraplegia. These two methods were a thoracic shunt with occlusion of the infrarenal aorta or cerebrospinal fluid drainage plus intrathecal papaverine injection, both of which were associated with an increased SCBF. Furthermore, papaverine dilated the anterior spinal artery (ASA) (p = 0.007) and increased the blood flow through the lower ASA. Whereas procedures utilizing a calcium channel blocker (flunarizine), allopurinol, superoxide dismutase (SOD), laminectomy alone, and a thoracoabdominal shunt not perfusing the arteria radicularis magna (ARM) all failed to prevent paraplegia, allopurinol (p = 0.026) and SOD (p = 0.004) did prevent gastric stress lesions, indicating that their failure to prevent paraplegia was not due to a lack of activity. Of great clinical interest is that, if a shunt is used and the ARM is perfused, infrarenal aortic cross-clamping increases SCBF, thus preventing paraplegia. Intrathecal application of papaverine proved to be even more effective in increasing SCBF and also completely prevented paraplegia. As this is a safer procedure than the insertion of shunts, this is the method of choice for the prevention of paraplegia associated with thoracic aortic cross-clamping. The preliminary trial using intrathecal papaverine in human beings has thus far shown no adverse side effects from the drug, and no paraplegia has occurred.
即使使用体外循环或分流术，胸主动脉交叉钳闭相关的截瘫发生率仍很高。在56只成年狒狒中，评估了脊髓血流量（SCBF）、血管解剖结构和截瘫发生率。通过放射性微球测量组织血流量。采用了各种方法来增加SCBF并预防缺血再灌注损伤。结果发现，截瘫发生率与神经组织缺血（SCBF）呈负相关，与再灌注充血呈正相关。两种方法完全预防了截瘫。这两种方法是肾下主动脉闭塞的胸部分流术或脑脊液引流加鞘内注射罂粟碱，两者均与SCBF增加有关。此外，罂粟碱使脊髓前动脉（ASA）扩张（p = 0.007），并增加了通过下ASA的血流量。而使用钙通道阻滞剂（氟桂利嗪）、别嘌呤醇、超氧化物歧化酶（SOD）、单纯椎板切除术以及未灌注大根动脉（ARM）的胸腹分流术等方法均未能预防截瘫，别嘌呤醇（p = 0.026）和SOD（p = 0.004）确实预防了胃应激性病变，表明它们未能预防截瘫并非由于缺乏活性。具有重大临床意义的是，如果使用分流术且灌注ARM，肾下主动脉交叉钳闭会增加SCBF，从而预防截瘫。鞘内应用罂粟碱在增加SCBF方面甚至更有效，也完全预防了截瘫。由于这是一种比分流术插入更安全的方法，因此这是预防胸主动脉交叉钳闭相关截瘫的首选方法。迄今为止，在人体中使用鞘内罂粟碱的初步试验未显示该药物有任何不良副作用，也未发生截瘫。
