Abstract: Background　After carotid artery stenting（CAS），microembolism occurs not only in the ipsilateral carotid artery blood supply area，but also in the contralateral carotid artery blood supply area and vertebrobasilar artery blood supply area.The risk factors，such as advanced age and carotid plaque ulceration，for microembolization in the carotid artery blood supply area ipsilateral to the stented carotid artery are relatively clear，but those for microembolization in carotid artery blood supply areas contralateral to the stented carotid artery are rarely mentioned in domestic studies.Objective　To investigate the occurrence of microembolism in the blood supply area of the contralateral carotid artery after unilateral CAS and analyze its risk factors.Methods　164 consecutive patients with carotid stenosis scheduled to undergo unilateral CAS from December 2013 to August 2018 in Department of Neurology，Weifang People's Hospital were enrolled.General data（sex，age，prevalence rates of hypertension，diabetes，hyperlipidemia，coronary heart disease，atrial fibrillation，and smoking，stroke history，preoperative carotid stenosis degree），postoperative clinical data（degree of carotid stenosis，degree of contralateral carotid stenosis，incidence of contralateral carotid occlusion，left carotid artery lesions，and type Ⅱ/Ⅲ aortic arch，and CAM score≥3），and use of closed-loop stent，and average number of catheters and/or guidewires used more than planned，as well as duration of surgery were collected and recorded.According to the results of MRI plain scan of brain within 3 days after CAS，patients with microembolism in posterior cerebral circulation blood area were excluded，the remaining ones were divided into two groups：ipsilateral group（with microembolization occurring at the ipsilateral side of carotid artery supply area）and contralateral group（with microembolization occurring at the contralateral carotid artery supply area or bilateral sides）．Results　163 of the 164 cases completed CAS.Plain MRI scan within 3 days after CAS found that 72 cases（44.2%）were newly microembolized，including 39 with ipsilateral microembolization（ipsilateral group），5 with contralateral microembolization and 13 with bilateral microembolization（contralateral group），and 15 with posterior circulation microembolization.Contralateral group showed higher incidence rate of left carotid artery lesions and higher rate of having CAM score ≥ 3 than ipsilateral group（P<0.05）．Multivariate Logistic regression analysis showed that the left carotid artery lesions〔OR=10.015，95%CI（2.728，42.680）〕，and CAM score≥ 3〔OR=9.137，95%CI（2.564，36.271）〕were associated with increased risk of microembolization at the contralateral carotid artery blood supply area after CAS（P<0.05）．Conclusion　Left carotid artery lesion and CAM score ≥ 3 are influencing factors for microembolization occurring at the contralateral carotid artery blood supply area after CAS，which suggests that complicated routes and severe aortic arch atherosclerosis can lead to significantly increased risk of microembolism in the contralateral carotid artery blood supply area after CAS.

Key words: Carotid stenosis, Stents, Intracranial embolism, Carotid artery stenting, Root cause analysis

摘要： 背景　颈动脉支架置入术（CAS）后微栓塞不仅发生于支架同侧颈动脉供血区，也常发生于支架对侧颈动脉供血区以及椎基底动脉供血区。目前CAS后发生支架同侧颈动脉供血区微栓塞的机制如高龄、颈动脉溃疡斑块等已相对明确，但CAS后支架对侧颈动脉供血区微栓塞的发生机制国内鲜有文献提及。目的　探讨单侧CAS后支架对侧颈动脉供血区微栓塞的发生情况，并分析其危险因素。方法　连续选取2013年12月—2018年8月在潍坊市人民医院神经内科就诊的拟行单侧CAS的颈动脉狭窄患者164例为研究对象。收集患者一般资料（性别、年龄、高血压发生情况、糖尿病发生情况、高脂血症发生情况、冠心病发生情况、心房颤动发生情况、吸烟情况、卒中史情况、术前颈动脉狭窄程度），记录术后颈动脉狭窄程度、术后支架对侧颈动脉狭窄程度、支架对侧颈动脉闭塞发生情况、左侧颈动脉病变发生情况、Ⅱ/Ⅲ型主动脉弓发生情况、CAM评分≥3分情况、闭环支架使用情况、平均增加导管和/或导丝数量、手术时间。根据CAS后3 d内的颅脑MRI平扫检查结果，剔除后循环供血区微栓塞患者，将剩余患者分为同侧组（支架同侧颈动脉供血区微栓塞）和对侧组（支架对侧颈动脉供血区微栓塞或支架两侧颈动脉供血区微栓塞）。结果　164例患者中有163例完成CAS，CAS后3 d内颅脑MRI平扫检查发现72例（44.2%）新发微栓塞（其中支架同侧颈动脉供血区微栓塞39例，支架对侧颈动脉供血区微栓塞5例，支架两侧颈动脉供血区微栓塞13例，后循环供血区微栓塞15例）。剔除发生后循环供血区微栓塞患者，剩余57例，将其分为同侧组（39例）和对侧组（18例）。对侧组左侧颈动脉病变发生率、CAM评分≥3分发生率高于同侧组（P<0.05）。多因素Logistic回归分析结果显示，左侧颈动脉病变〔OR=10.015，95%CI（2.728，42.680）〕、CAM评分≥3分〔OR=9.137，95%CI（2.564，36.271）〕是颈动脉狭窄患者CAS后发生支架对侧颈动脉供血区微栓塞的影响因素（P<0.05）。结论　发生左侧颈动脉病变以及CAM评分≥3分是CAS后支架对侧颈动脉供血区微栓塞的危险因素，提示复杂的路径以及严重的主动脉弓斑块可能导致CAS后支架对侧颈动脉供血区微栓塞的发生概率增加。

关键词: 颈动脉狭窄, 支架, 颅内栓塞, 颈动脉支架置入术, 影响因素分析