高信号血管征与颈动脉内膜切除术后脑过度灌注的相关性研究

Association between hyperintense vessel sign and cerebral hyperperfusion after carotid endarterectomy

目的探讨术前T2-液体衰减反转恢复(FLAIR)序列高信号血管征(HVS)是否可以预测颈动脉内膜切除术(CEA)后脑过度灌注的发生。方法前瞻性连续入组2020年7月至2022年2月就诊于北京协和医院血管外科同意接受CEA的重度颈动脉狭窄患者。所有患者在术前2周和术后1周内完成MR检查。采集患者临床资料,包括年龄、性别、临床症状、系统性血管危险因素(包括高血压病、糖尿病、高脂血症、冠心病、吸烟史)和术后即刻至出院前最高收缩压。通过影像学图像,评估手术侧和对侧颈动脉的狭窄程度、是否存在梗死灶、Willis前环是否完整。术中记录转流管的使用情况。根据术前T2-FLAIR序列图像中HVS在大脑中动脉供血区的分布范围,将HVS分为0~3级:0级为未见HVS;1级为HVS局限在外侧裂池;2级为HVS延伸至颞枕叶;3级为HVS延伸至额顶叶。通过MR准连续动脉自旋标记序列获得患者的脑血流量图。过度灌注定义为与术前相比,同侧大脑中动脉供血区脑血流量增加超过100%。根据过度灌注指数将患者分为过度灌注组和非过度灌注组,比较两组的临床危险因素和HVS分级,使用Logistics回归分析方法分析HVS分级与术后脑过度灌注间的关系,使用受试者工作特征(ROC)曲线分析计算HVS预测脑过度灌注的最佳临界值。结果共纳入92例患者,其中过度灌注组18例(19.6%),非过度灌注组74例(80.4%)。单因素分析显示,两组患者术前HVS分级分布差异有统计学意义(P<0.01),过度灌注组以HVS 3级为主(10例),非过度灌注组以HVS 0级(42例)为主。Logistics回归分析结果显示,术前HVS 2~3级是CEA术后脑过度灌注发生的独立预测因素(OR=12.222,95%CI:3.198~46.715,P<0.01)。ROC曲线分析表明,HVS分级2级是预测CEA术后脑过度灌注的最佳临界值(曲线下面积为0.767,95%CI:0.630~0.910,P<0.01),使用这一标准预测脑过度灌注的敏感度为72.2%,特异度为79.7%,阳性预测值46.4%,阴性预测值92.2%。结论术前T2-FLAIR序列上HVS与CEA术后脑过度灌注相关,HVS≥2级可能有助于预测CEA术后脑过度灌注的发生。本研究结果仍需大样本数据进一步证实。

Objective To investigate whether hyperintense vessel sign(HVS)on preoperative T2-fluid-attenuated inversion recovery(FLAIR)images can predict cerebral hyperperfusion after carotid endarterectomy(CEA).Methods From July 2020 to February 2022,patients who underwent CEA due to severe carotid stenosis were enrolled prospectively and consecutively at the Department of Vascular Surgery of Peking Union Medical College Hospital.All patients underwent MRI within 2 weeks before CEA and 1 week after CEA.Clinical data were collected,including age,gender,clinical symptoms,systemic vascular risk factors(including hypertension,diabetes,hyperlipidemia,coronary artery disease and smoking)and maximum postoperative systolic blood pressure before discharge.The degree of stenosis of ipsilateral and contralateral carotid artery,infarction,and the integrity of the anterior Willis circle were assessed based on radiological images.The use of intraluminal shunt was recorded.According to the distribution in the middle cerebral artery territory on preoperative T2-FLAIR images,HVS was divided into grade 0-3:grade 0 indicated no HVS;grade 1 indicated HVS limited in sylvian fissure;grade 2 indicated HVS limited in Sylvian fissure and the temporal-occipital junction;grade 3 indicated HVS extended to the frontal-parietal lobes.Cerebral blood flow maps were obtained by pseudo-continuous arterial spin labeling MR.Hyperperfusion was defined as an increase in cerebral blood flow greater than 100%in the ipsilateral middle cerebral artery territory compared with baseline.According to the hyperperfusion index,the patients were divided into hyperperfusion group and non-hyperperfusion group.Clinical risk factors and HVS grade were compared between groups.Logistic regression analysis was used to determine the relationship between HVS and cerebral hyperperfusion,and the optimal cut-off value of HVS for predicting cerebral hyperperfusion was calculated by using receiver operating characteristics(ROC)curve analysis.Results A total of 92 patients were included in the analysis,including 18(19.6%)patients in the hyperperfusion group,74(80.4%)patients in the non-hyperperfusion group.Univariate analysis showed that there was significant difference in the distribution of preoperative HVS grade between the two groups(P<0.01).In the hyperperfusion group,grade 3(10 cases)was common,while in the non-hyperperfusion group,grade 0(42 cases)was common.The results of Logistic regression analysis showed that preoperative grade 2-3 HVS was an independent predictor of cerebral hyperperfusion(OR,12.222,95%CI 3.198-46.715,P<0.01).ROC curve analysis showed that HVS grade 2 was the optimal cut-off for predicting cerebral hyperperfusion(area under the curve 0.767,95%CI 0.630-0.910,P<0.01)with the sensitivity of 72.2%,specificity of 79.7%,positive predictive value of 46.4%,and negative predictive value of 92.2%.Conclusions HVS on preoperative T2-FLAIR images is associated with cerebral hyperperfusion after CEA,HVS grade≥2 may help predict the occurrence of cerebral hyperperfusion.The results of this study need to be further confirmed by large sample data.