1.Fudan University;2.Shanghai Jing'3.'4.an District Central Hospital;5.Dongfang Hospital Affiliated to Tongji University
目的 FFR作为一种实现动脉狭窄的功能性评估的参数已经被用于冠状动脉狭窄，也有人提出将其用于颈动脉狭窄的评估中。本文探索将FFR引入颈动脉狭窄评估的可行性，并且分析血管壁弹性模量对颈动脉狭窄中的血液动力学参数的影响和对FFR的计算结果的影响。方法 利用计算机辅助设计软件建立颈动脉分叉的标准模型并获得不同狭窄率的模型。假设血管壁为线弹性材料，血液为不可压缩牛顿流体，在脉动流条件下，利用有限元分析软件进行颈动脉狭窄模型中血液流动的流固耦数值模拟，获得各种血液动力学参数，并计算相应的FFR值。结果 当弹性模量固定时，随着狭窄率的增加模型中狭窄部位的FFR值逐渐减小，且此时其弹性壁与刚性壁的FFR值相对差异随着狭窄率的增加而增加；当狭窄率固定为70%时，随着弹性模量的增加FFR值会逐渐减小。结论 采用FFR来对颈动脉狭窄程度进行功能性评估需要考虑血管壁弹性的影响；狭窄率越大，血管壁的弹性模量对FFR值的影响越大。
Objective As a parameter for functional assessment of coronary artery stenosis FFR has been used in clinic. It has also been suggested to be used in the assessment of carotid artery stenosis. This study explored the feasibility of applying FFR into the assessment of carotid stenosis. The effects of elastic modulus of vessel wall on hemodynamic parameters and FFR of the standard carotid artery stenosis model were also analyzed. Methods Standard models of carotid bifurcation and stenosis models with different stenosis rates were established by computer-aided design software. Assuming that the vessel wall was linear elastic material and the blood was incompressible Newtonian fluid, the fluid-structure coupling simulation of blood flow in carotid artery stenosis model under the pulsating flow was carried out by finite element analysis, and the relevant hemodynamic parameters were obtained, and the corresponding FFR was calculated. Results When the modulus of elasticity is fixed, the FFR of the narrow part of the model decreases gradually with the increase of the stenosis rate, and the relative difference between the FFR of the elastic wall and the rigid wall increases with the increase of the stenosis rate; when the stenosis rate is fixed at 70%, the FFR decreases gradually with the increase of elastic modulus. Conclusion The effect of vascular wall elasticity should be considered during the modelling; The greater the stenosis rate, the greater the influence of elastic modulus of vessel wall on FFR.