Lopez-Bresnahan M V, Kearse L A, Yanez P, Young T I
Department of Anesthesia, Massachusetts General Hospital, Boston.
J Neurosurg. 1993 Sep;79(3):379-82. doi: 10.3171/jns.1993.79.3.0379.
The purpose of this study was to determine whether preoperative angiographic patterns of collateral cerebral blood flow correlate with protection against intraoperative electroencephalographic (EEG) evidence of cerebral ischemia caused by carotid artery cross-clamping during carotid endarterectomy. Previous studies have shown that contralateral carotid artery occlusion and intracranial stenoses are associated with cerebral ischemia during carotid endarterectomy; however, the angiographic collateral flow patterns associated with cerebral ischemia have not been identified. This paper reports a retrospective study of 67 patients who underwent two- to four-vessel cerebral angiography followed by carotid endarterectomy with 16-channel EEG monitoring. The angiograms were reviewed for extracranial occlusive disease and collateral flow patterns, and the EEG recordings were analyzed for ischemic changes during carotid artery cross-clamping. Statistical analysis was by Fisher's exact test. Cross-filling of the anterior and middle cerebral arteries from the contralateral carotid artery through the anterior communicating artery correlated with a decreased incidence of EEG ischemic changes. Only 21% of patients with this collateral flow pattern showed ischemic changes compared to 50% of patients without this pattern (p < 0.03). Three angiographic findings occurring in combination on the side contralateral to surgery correlated with EEG ischemia: 1) occlusion of the contralateral internal carotid artery (five of seven or 71%, p < 0.03); 2) collateral flow from the external carotid circulation to the internal carotid circulation via the ophthalmic artery; and 3) collateral flow from the posterior circulation to the contralateral anterior circulation via the posterior communicating artery. The data presented here corroborate the correlation between contralateral carotid artery occlusion and cerebral ischemia during carotid endarterectomy. They also demonstrate that cross-filling of the anterior and middle cerebral arteries by the contralateral carotid artery protects against such ischemia. This collateral flow may serve as an indicator of tolerance to carotid artery cross-clamping.
本研究的目的是确定术前大脑侧支血流的血管造影模式是否与颈动脉内膜切除术期间颈动脉交叉钳夹所致脑缺血的术中脑电图（EEG）证据的保护作用相关。先前的研究表明，对侧颈动脉闭塞和颅内狭窄与颈动脉内膜切除术期间的脑缺血有关；然而，与脑缺血相关的血管造影侧支血流模式尚未明确。本文报告了一项对67例患者的回顾性研究，这些患者在接受两至四血管脑动脉造影后接受了颈动脉内膜切除术，并进行了16通道EEG监测。对血管造影进行颅外闭塞性疾病和侧支血流模式评估，并分析EEG记录以观察颈动脉交叉钳夹期间的缺血变化。采用Fisher精确检验进行统计学分析。大脑前动脉和大脑中动脉通过前交通动脉由对侧颈动脉交叉充盈与EEG缺血变化发生率降低相关。具有这种侧支血流模式的患者中只有21%出现缺血变化，而无此模式的患者中这一比例为50%（p<0.03）。手术对侧同时出现的三个血管造影表现与EEG缺血相关：1）对侧颈内动脉闭塞（7例中的5例，即71%，p<0.03）；2）颈外循环通过眼动脉向颈内循环的侧支血流；3）后循环通过后交通动脉向对侧前循环的侧支血流。此处呈现的数据证实了颈动脉内膜切除术期间对侧颈动脉闭塞与脑缺血之间的相关性。它们还表明，对侧颈动脉对大脑前动脉和大脑中动脉的交叉充盈可预防此类缺血。这种侧支血流可作为对颈动脉交叉钳夹耐受性的指标。
