Waterford Stephen D, Rastegar Michelle, Goodwin Erin, Lapchak Paul A, Juan Viviana, Haji Farnaz, Bombien René, Khoynezhad Ali
Division of Cardiothoracic Surgery, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Suite 3306, Los Angeles, CA, 90048, USA.
Transl Stroke Res. 2015 Oct;6(5):399-406. doi: 10.1007/s12975-015-0406-x. Epub 2015 May 20.
Spinal cord ischemia (SCI) is a devastating complication of aortic operations. Neuromonitoring using motor evoked potentials (MEPs) is a sensitive modality to detect SCI in humans. We describe a leporine SCI model using MEPs to test pharmaceutical therapeutics and other neuroprotective adjuncts. In 80 rabbits, methods to obtain MEPs in normotensive and ischemic rabbits were developed. The effects of isoflurane, propofol, apnea, and hypotension on lower extremity MEPs were studied. Lower extremity MEPs disappear upon SCI induction in 78 of 78 (100 %) rabbits. Prior to SCI induction and during apneic episodes, lower extremity MEPs were lost in all (100 %) and upper extremity MEPs in one (25 %). Isoflurane was used in four experiments, with loss of lower extremity MEPs in all four (100 %) and loss of upper extremity MEPs in zero. With propofol upper extremity, MEPs were obtainable in 80 of 80 rabbits (100 %) and lower extremity MEPs in 78 of 80 rabbits (97.5 %) prior to SCI induction. The presence of these lower extremity MEPs prior to SCI induction was not correlated with systolic or diastolic blood pressure. Disappearance of MEPs occurred in all 45 rabbits with postoperative lower extremity impairment. MEPs in the leporine model correlate closely with paraplegia. MEPs are influenced by inhaled anesthetics and apnea but not by hypotension alone. Propofol anesthesia provides reliable MEPs. This study provides the basis for a reproducible model of SCI to be used for novel therapeutic drug development.
脊髓缺血（SCI）是主动脉手术的一种毁灭性并发症。使用运动诱发电位（MEP）进行神经监测是检测人类脊髓缺血的一种敏感方法。我们描述了一种利用MEP的兔脊髓缺血模型，用于测试药物治疗和其他神经保护辅助措施。在80只兔子中，开发了在血压正常和缺血兔子中获取MEP的方法。研究了异氟烷、丙泊酚、呼吸暂停和低血压对下肢MEP的影响。在78只（100%）兔子中，诱导脊髓缺血后下肢MEP消失。在诱导脊髓缺血前和呼吸暂停期间，所有兔子（100%）的下肢MEP均消失，一只兔子（25%）的上肢MEP消失。在四项实验中使用了异氟烷，所有四只兔子（100%）的下肢MEP均消失，上肢MEP无一消失。使用丙泊酚时，在诱导脊髓缺血前，80只兔子中有80只（100%）可获得上肢MEP，80只兔子中有78只（97.5%）可获得下肢MEP。诱导脊髓缺血前这些下肢MEP的存在与收缩压或舒张压无关。所有45只术后下肢受损的兔子MEP均消失。兔模型中的MEP与截瘫密切相关。MEP受吸入麻醉剂和呼吸暂停的影响，但不受单纯低血压的影响。丙泊酚麻醉可提供可靠的MEP。本研究为用于新型治疗药物开发的可重复脊髓缺血模型提供了基础。
