单侧症状性颈动脉狭窄行颈动脉支架置入术后新发DWI高信号与脑血流变化

New-onset DWI high signal and cerebral blood flow changes after CAS for unilateral symptomatic carotid artery stenosis

目的比较单侧症状性颈动脉狭窄患者行颈动脉支架置入术(CAS)前后脑血流动态变化与围手术期事件的关系,为患者选择手术方式提供参考。方法纳入2018年1月至2020年6月北京中医药大学东方医院收治的24例单侧症状性颈动脉中重度狭窄(>50%)患者24例,均行CAS。所有患者分别在术前3 d内,术后第3天行核磁共振扫描(包括DWI和三维准连续式动脉自旋标记灌注成像)。测量脑血流变化和围手术期事件,并根据是否有新发DWI高信号分为微栓塞组和无栓塞组。结果新发DWI高信号发生率高(17例,70.8%),共发现176个病灶,但仅1例出现症状,主要位于患侧额顶叶皮质/皮质下(60.8%),大部分<3 mm(92.6%);术后额顶叶脑血流高于颞叶脑血流(患侧50.49±8.02 vs 47.94±9.08,t=2.179,P<0.05;健侧50.16±5.79 vs 48.00±5.98,t=3.835,P<0.05);额顶叶及颞叶患侧术后的脑血流均比术前明显升高(P<0.05)。微栓塞组额顶叶术前脑血流低于无栓塞组(P<0.05)。结论CAS患者微栓塞发生率高,可能不是主要由血流动力学改变直接引起的,而是与术前长期脑低灌注导致脑血流调节功能损伤相关。

Objective To compare the relationship between the dynamic changes of cerebral blood flow(CBF)before and after carotid artery stent(CAS)placement and perioperative events in patients with unilateral symptomatic carotid artery stenosis,providing reference for patients to choose surgical methods.Methods A total of 24 patients with moderate to severe(>50%)symptomatic unilateral carotid artery stenosis admitted in Dongfang Hospital,Beijing University of Chinese Medicine from January 2018 to June 2020 were included,all of whom underwent CAS.All patients underwent magnetic resonance imaging(including DWI and 3D quasi continuous arterial spin labeled perfusion imaging)within 3 days before and 3 days after surgery.Changes in CBF and perioperative events were measured.According to whether there were new DWI high signals,they were divided into micro-embolic group and non-embolic group.Results While the incidence of new DWI lesions was high(17/24,70.8%)and 176 lesions were observed among the 17 cases,there was only one subject showing the symptoms.The majority of the lesions were located at the cortex/subcortex of the ipsilateral frontal and parietal lobes(60.8%),and 92.6% of the lesions size being less than 3 mm.The CBF in the frontoparietal lobe were higher than that in the temporal lobe after surgery(lesion side 50.49±8.02 vs 47.94±9.08,t=2.179,P<0.05;contralateral side 50.16±5.79 vs 48.00±5.98,t=3.835,P<0.05);the CBF of the lesion side of the frontoparietal and temporal lobes increased significantly after surgery compared to before surgery(P<0.05).The preoperative relative CBF in the frontal parietal lobe of the micro-embolization group was lower than that of the non-embolization group(P<0.05).Conclusion The high incidence rate of micro-embolism in patients receiving CAS may not be the result of direct changes of hemodynamics in the brain but rather the loss of CBF regulation due to long-term hypoperfusion prior to the stenting.