高流量搭桥治疗颈动脉及其主干狭窄或闭塞性卒中的脑血流动力学和脑代谢的研究

Main reason for ischemic stroke is either occlusion or stenosis of the main branches of the carotid artery.In this study, total of 60 cases with either occlusion or stenosis of the carotid artery will be divided into two groups (1:1)as surgical and non-surgical groups.In surgical group, all 30 cases will undergo highflow bypass surgery with the radial artery as a graft vessel anastomosing internal maxillary artery and the middle cerebral artery where as the 30 cases in the non-surgical group undergo conservative treatment.In surgical group, intraoperative ultrasound is to be done to monitor the blood flow during the operation so as to compare the differences between blood flow in the artery before and after the bypass surgery. Computed tomography angiography (CTA) is to be done during the postoperative period,0.5 year、1 year、1.5 years and 2 years after the surgery to assess the patency of the bypass graft vessel.To evaluate 30 days mortality in both the groups, perfusion weighted image (PWI) will be performed and the regional cerebral blood volume (CBV), regional cerebral blood flow (CBF), mean cerebral perfusion time (MTT) and cerebral blood flow of time to peak (TTP) will be analysed. Changes in brain tissue oxygen absorption fraction (OEF) and cerebral oxygen metabolic rate (CMRO2) in both the groups will be analysed with the Positron emission tomography (PET).We will analyse the reccurance rate of stroke in the same hemisphere and the changes in quality of life during the 2 years duration after the treatment in both the groups. The study of hemodynamic and metabolic status of the brain after the high flow bypass surgery will provide strong evidence in its application in the treatment of ischemic stroke.

颈动脉及其主干狭窄或闭塞是缺血性卒中主要原因，本研究对60例颈动脉及其主干狭窄或闭塞患者随机分组。30例患用桡动脉移植，颌内动脉与大脑中动脉高流量搭桥治疗颈动脉及主干狭窄或闭塞性卒中,30例为非手术治疗。在手术搭桥患者中，用定量血管超声技术，测定术中搭桥前、后阻塞血管血流量变化和围手术期、术后6个月、1年、1年零6个月和2年搭桥后的血管造影（CTA），确定搭桥血管开通率、评价手术组和非手术组患者30天内病死率、核磁共振脑血流灌注（PWI）的局部脑血容量(CBV)、局部脑血流（CBF)、平均脑血流灌注时间（MTT)和脑血流峰值时间（TTP)；正电子CT扫描（PET）的脑组织氧吸收分数(OEF)和脑氧代谢率(CMRO2)变化,并对两组患者2年内病变侧半球再次卒中发生率和日常生活能力量表对比分析，研究高流量血管搭桥治疗缺血脑组织的血流动力学和脑组织代谢变化，为高流量血管搭治疗缺血性卒中提供依据。

缺血性脑卒中具有高致死率，高致残率的特点，已成为危害我国城乡居民健康和生命的主要疾病之一。其中，近1/3是由慢性颈内动脉闭塞或大脑中动脉严重狭窄（>90%）或闭塞引起，而治疗该慢性缺血性脑血管病的关键是：改善缺血脑组织的血流灌注。基于多年的临床血管影像观察和血管实体解剖研究，我们发现：选择颌内动脉（又称上颌动脉）为颅外供血血管，截取自体桡动脉为桥血管，与颅内血管搭桥，可提供较充足的血流量。然而，颌内动脉搭桥治疗慢性缺血性脑血管病的血流动力学，脑糖代谢和中长期预后效果并不明确。本研究中，我们通过超声多普勒对搭桥后术中桥血管血流动力学进行评估发现：当血压维持在120-130/70-80 mmHg时，颌内动脉搭桥组桥血管血流量(FV)高于颞浅动脉搭桥组FV: (27.25±9.32 (22.62-31.88) ml/min VS 81.36±30.41 (62.05-100.70) ml/min, P<0.01；通过核磁灌注成像(PWI)对脑血流动力学进行评估发现：患者缺血侧感兴趣区(ROI)的rCBF，rCBV较健侧ROI下降比例分别为0.81，0.48；搭桥后分别为0.23，P<0.01；0.06，P<0.01。颌内动脉搭桥前患者缺血侧ROI的MTT，TTP较健侧ROI延长的比例分别为0.90，0.97；搭桥后分别为0.13，P<0.01；0.06，P<0.01；通过18-氟脱氧葡萄糖(18F-FDG)正电子断层扫描(PET/CT)对脑代谢进行评估发现：患者经颌内动脉搭桥前缺血侧感兴趣区18F-FDG 的标准化摄取值的平均值(SUVavg) 4.76±2.35 (3.08-6.04)低于对侧SUVavg 5.99±2.63 (4.11-7.87)，P=0.03；搭桥后两侧SUVavg 无差异，缺血侧5.26±2.23 (3.67-6.86)，对侧5.05±1.58 (3.91-6.18)，P=0.45。中长期随访结果：患者围手术期死亡率和缺血性脑卒中发生率为0，2年内无失访，生存率100%，均无新发神经功能缺失，无新发缺血性脑卒中。综上，颌内动脉搭桥单位时间内可以提供更高的血流量，可以改善缺血患者的脑血流动力学和脑代谢，是治疗慢性缺血性脑血管病的一种安全，有效搭桥方式，可以在临床推广应用。