缝合式和机械吻合式搭桥模型的血流动力学数值模拟

为了说明机械吻合器的引入对冠状动脉搭桥术近端吻合区血流动力学因素的影响，运用Solidworks软件构造了缝合式和机械吻合式两种搭桥模型。运用有限单元数值模拟的方法和Fluent6.3软件,对两种模型移植血管中脉动流进行数值化模拟和可视化分析。获得了吻合区在一个心动周期内不同时刻的速度场、二次流、压力及壁面切应力的分布情况。结果表明，机械吻合器的引入在增大移植血管中血流速度（大于缝合模型约0.2 m/s）的同时使得低速区范围增大，吻合区壁面切应力变化范围为0～50 Pa，应力集中现象明显，壁面切应力变化剧烈，易引起血小板活化和内膜增生。为了提高冠状动脉搭桥术的通畅率，对机械吻合器进行优化设计很有必要。

Numerical Simulation of Hemodynamics in Suturing and Sutureless Anastomotic Models

In order to clarify the influence of the sutureless anastomotic devices on hemodynamic factors in proximal anastomosis in coronary artery bypass graft (CABG), suturing and sutureless anastomotic models were constructed by software Solidworks. The pulsatile flows in the two models were simulated and analyzed with finite element method and software Fluent 6.3. The distribution of velocity, second flow, pressure and wall shear stress were calculated with a function of time in a cardiac cycle. Results showed that using the sutureless anastomotic devices enlarged the area of low velocity, which was 0.2 m/s higher than suturing model, while increased the magnitude of the velocity in grafts. The wall shear stress in anastomosis ranged from 0 to 50 Pa and changed dramatically, besides, stress concentration was more serious in sutureless anastomotic model, which would lead to the activation of the platelets and intimal hyperplasia. Optimal design of sutureless anastomotic devices is necessary for the improvement of CABG patency rates.