流固耦合分析血液黏滞系数对重度狭窄颈动脉的影响

摘要

Objective This study was to evaluate different blood viscosity coefficients' effects on blood flow velocity and wall shear stress (WSS) in stenotic carotid artery by using fluid structure interaction (FSI) mechanics analysis. Methods In August 2015, in Tianjin 4th Centre Hospital, a 62 year-old male patient whose computed tomography angiography (CTA) image data indicated severe internal carotid stenosis was selected. The patient's CTA image data was modelled and loaded into FSI software. Blood viscosity coefficients were set to 1, 3.5, 6, 8.5, and 11 cP, respectively. The velocities and WSS values of the carotid bifurcation anterior end (A1), carotid sinus horizontal segment (A2), internal carotid stenosis (A3), and internal carotid stenosis distal end (A4) were measured. Results As the blood viscosity coefficient was increased, the average blood flow velocities of A1, A2, A3, and A4 were decreased, while all the WSS values were increased. As the central blood flow velocity of A4 was decreased, the central blood flow velocities of A1, A2 and A3 were increased. Conclusion In patient with severe carotid stenosis, when the blood viscosity coefficient was increased, the insufficient of blood supply to brain got worse, may increase probability of acute stroke, and plaque rupture at stenosis area. Hence, aggressive intervention is needed when presence of increasing blood viscosity coefficient in clinical practice.%目的 基于流固耦合(FSI)力学的方式,分析不同血液黏滞系数对重度狭窄颈动脉的血液流速及壁面剪切力(WSS)的影响.方法 选取2015年8月于天津市第四中心医院经CT血管成像(CTA)检查诊断为颈内动脉重度狭窄(狭窄程度为75%)的1例62岁男性病人,将其CTA影像数据制作模型,导入FSI分析软件中,分别设定血液黏滞系数为1、3.5、6、8.5、11 cP并进行运算.在运算结果中测量并分析颈总动脉末端(A1)、颈动脉窦水平(A2)、颈内动脉狭窄处(A3)、颈内动脉狭窄处远端(A4)截面的血液流速和WSS值.结果 随着血液黏滞系数的升高,A1、A2、A3、A4的血流速度均值降低,WSS均值增大;A4的中心血液流速降低,A1、A2和A3的中心血流速度升高.结论 随着颈动脉重度狭窄病人的血液黏滞系数升高,其脑部供血不足趋于严重化,从而导致急性脑卒中的发生,而且造成狭窄位置斑块的破损概率和面积进一步增大,因此应引起临床的高度重视并及时干预.