基于计算流体动力学大脑中动脉闭塞急性缺血性脑卒中再灌注治疗后出血转化初步研究

目的探讨基于计算流体动力学(computational fluid dynamics,CFD)大脑中动脉闭塞引起的急性缺血性脑卒中的血流动力学与再灌注治疗后出血转化的关系。材料与方法纳入磁共振血管造影(magnetic resonance angiography,MRA)证实的大脑中动脉闭塞的急性缺血性脑卒中患者共38例,搜集治疗前MRA数据和入院时一般临床资料进行回顾性分析。基于MRA-CFD模型模拟血流动力学,获得血流动力学参数如下:血压(pressure)、壁切应力(wall shear stress,WSS)及壁切应力梯度(wall shear stress gradient,WSSG)。Rpressure、RWSS及RWSSG分别为大脑中动脉起始处与闭塞处正常管径压力、WSS及WSSG的比值。所有患者接受标准治疗。根据治疗后48 h内随访CT或MRI有无出血分为出血组和未出血组。比较两组间临床及血流动力学参数差异并进行相关性分析。结果总共纳入38例患者,出血组17例,未出血组21例。与未出血组相比,出血组有更多的高血压患者(P=0.008)、更高的入院收缩压[(149.1±23.9) mm Hg与(139.3±16.3) mm Hg比较,P=0.024]及舒张压[(90.2±16.7) mm Hg与(87.7±8.5) mm Hg比较,P=0.008]、更高的血浆同型半胱氨酸[(16.6±11.1)μmol/L与(13.2±3.5)μmol/L比较,P=0.024]。出血组较未出血组,RWSS和RWSSG更高(P<0.05),而Rpressure无统计学差异(P>0.05)。相关性分析显示高血压(r=-0.428,P=0.007)、RWSS(r=-0.341,P=0.036)与脑梗再灌注治疗后出血转化有统计学差异。结论高血压及局部血管内RWSS与大脑中动脉闭塞急性缺血性脑卒中患者再灌注治疗后出血转化有关,且入院时高血压及再灌注治疗前局部血管内高RWSS更可能导致再灌注治疗后出血转化。

Computational fluid dynamics analysis of hemorrhagic transformation after reperfusion therapy in acute ischemic stroke patients with middle cerebral artery occlusion

Objective: To explore the relationship between hemodynamics of acute ischemic stroke(AIS) caused by middle cerebral artery occlusion and hemorrhagic transformation(HT) after reperfusion therapy based on computational fluid dynamics(CFD). Materials and Methods: A total of 38 AIS patients with middle cerebral artery occlusion confirmed by magnetic resonance angiography(MRA) were included. The data of MRA before treatment and general clinical data at admission were collected and analyzed retrospectively. Based on MRA-CFD models, hemodynamic parameters were obtained as follows: pressure, wall shear stress(WSS) and wall shear stress gradient(WSSG). Rpressure, RWSS, RWSSG is defined as the ratio of pressure, WSS, WSSG at the beginning of middle cerebral artery to the normal diameter of occlusion, respectively. All patients received standard treatment. According to whether there is bleeding on CT or MRI within 48 hours after treatment, the patients were divided into bleeding group and non-bleeding group. We compared the differences of clinical and hemodynamic parameters between the two groups and underwent correlation analysis. Results: Out of 38 patients, there were 17 patients in the bleeding group and 21 patients in the non-bleeding group. Compared with the non-bleeding group, the bleeding group had more hypertension patients(P=0.008), higher admission systolic blood pressure [(149.1±23.9) mm Hg VS(139.3±16.3) mm Hg,P=0.024] and diastolic blood pressure [(90.2±16.7) mm Hg VS(87.7±8.5) mm Hg, P=0.008], higher plasma homocysteine [(16.6±11.1) μmol/L VS(13.2±3.5) μmol/L, P=0.024]. RWSS and RWSSG in the bleeding group were higher than those in the non-bleeding group(P<0.05), whilethere was no statistical difference regarding to Rpressure(P>0.05). Correlation analysis showed that hypertension(r=-0.428, P=0.007) and Rwss(r=-0.341, P=0.036) had statistical difference with HT after reperfusion therapy. Conclusions: Hypertension, local intravascular RWSS were associated with HT after reperfusion therapy in patients with acute ischemic stroke due to middle cerebral artery occlusion, hypertension and local intravascular high RWSS before treatment were more likely to lead to HT after reperfusion treatment.