体感诱发电位在复杂动脉瘤血管架桥及重建术中的应用

目的探讨体感诱发电位（SEP）在复杂动脉瘤血管架桥及重建手术中的应用。方法回顾分析2002～2008年24例复杂动脉瘤病人进行动脉瘤血管架桥及重建手术，术中分别采用动脉瘤切除远近端血管吻合，动脉瘤孤立加大隐静脉高流量搭桥或颞浅动脉低流量搭桥等方式处理动脉瘤，实时进行体感诱发电位监测：胫后神经刺激，记录双侧皮层的SEP。将P40波幅下降一半作为脑缺血的预警信号，潜伏期延长3ms作为参考。结果4例行动脉瘤切除远近端血管吻合，16例行大隐静脉高流量血管搭桥术，4例行颞浅动脉低流量血管搭桥。监测结果：Ⅰ型无变化16例；Ⅱ型加重但逐渐恢复：波幅下降一半，但稳定且略有回升4例；Ⅲ型加重无恢复：波幅下降一半，且继续下降，升高血压也无明显改善3例；Ⅳ型波形扁平且无恢复1例；Ⅴ型波形消失0例。结论在复杂动脉瘤手术中，术中体感诱发电位的监测可以提示血流阻断后脑供血情况及功能区脑灌注状态。对颅内动脉瘤手术的安全性提供了一定的保障，减少了手术风险，是一种简便、安全有效的监测技术。

Application of somatosensory evoked potential in by-pass and reconstruction surgery in complex aneurysms

Objective To study the applications of somatosensory evoked potential （SEP） in the by- pass and reconstruction surgery in complex aneurysms. Methods 24 patients with complex aneurysms were treated by by-pass and reconstruction surgery from 2002 to 2008. The surgery methods include vascular anastomosis after aneurysm resection, saphenous vein-to-middle cerebral artery high-flow bypass and superficial temporal artery-to-middle cerebral artery low-flow bypass with aneurysm isolation. Real time of SEP including posterior tibial nerve stimulation was conducted to record bicortical sensory evoked potential. Half reduction of the amplitude of P40 was the early warning of cerebral ischemia, more than 3ms extended latency period was regarded as a reference. Results Vascular anastomosis after aneurysm resection was performed in 4 cases, saphenous vein-to-middle cerebral artery high-flow bypass performed in 16, superficial temporal artery-to-middle cerebral artery low-flow bypass performed in 4. Monitoring results showed that type Ⅰ was no change in 16, Ⅱ aggravation at first and recovered gradually in 4 which showed wave decreased to half of the amplitude of P40 but stabilized and slightly ascend,Ⅲ aggravation with no recovery in 3 which showed decreased more than half of the amplitude of P40 and keep on decreasing even using methods to increase blood pressure, Ⅳ wave form was flatten in 1, Ⅴ wave form disappeared in no case. Conclusions Intraoperative monitoring SEP may give evidence of cerebral perfusion state and blood supply state after occlusion of parent artery in the surgery of complexe aneurysm,which can ensure the safety of the surgery,reduce operative risk. It is a feasible, safe, and very reliable technique in complex aneurysm sugery.