诱发电位应用于降主动脉手术的研究

目的 通过比较单纯阻断与左心转流技术在胸降主动脉手术中对脊髓缺血损伤的影响,评价在主动脉手术中应用皮质体感诱发电位监测脊髓缺血的可行性,.方法 12头小型猪随机分为单纯阻断和左心转流组.均采用左胸肋间入路开胸,在左无名动脉以远阻断降主动脉.术中使用诱发电位监测仪连续监测皮质体感诱发电位(CSEP),监测脊髓功能变化.术后每日记录动物行为学评分.术后7 d处死动物,观察脊髓组织细胞的超微结构.结果 单纯阻断组中2头动物后肢轻瘫,其余后肢均截瘫.左心转流组动物恢复顺利,无截瘫发生.单纯阻断组CSEP波幅降低达50%以上,潜伏期延长10%以上,变化与行为学评分一致.阻断平面以下脊髓的超微结构显示,单纯阻断组脊髓髓鞘板层结构破坏严重,线粒体肿胀,破坏.左心转流组与阻断平面以上脊髓比较,变化不明显.结论 在动物模型中,CSEP对脊髓缺血状况的监测及时有效.

Application of CSEP during thoracic descending aortic operation

Objective By comparing the effects of single clamp (SC) vs lett heart bypass (LHB) on spinal isvhemia injury during thoracic descending aortic operation,to investigate the feasibility of cortical somatosensory evoked potentials (CSEP) monitoring spinal cord ischemia. Methods Twelve mini-pigs were randomly divided into two groups : SC group and LHB group. The lett intercostal incision was made. The thoracic desecending aorta was clamped under lett innominate artery outlet. CSEP was re- corded to monitor the function of spinal cord. The behavior scores were observed every day after operation. Mini-pigs were sacrificed at the 7th day postoperatively. The uhrastructural changes were observed under an electron microscope. Results The operations were successful. Two animals developed incomplete pa- ralysis, and the rest 4 paraplegia in SC group. The animals in LHB group recovered completely, and there was no paralysis or paraplegia. The record of CSEP showed the amplitude was decreased to below 50% of baseline, and latency was prolonged beyond 10% of baseline in SC group but not in LHB group. The change of SEP was at equal pace with that of behavior score. The ultramierostructures of spinal cord under the clamp plane indicated serious damage of layers, swelling and damage of mitochondria in SC group, while the morphology was almost normal in LHB group. Conclusion For animal model, monitoring of spi-nal cord ischemia using CSEP was promptly and feasibe.