目的 为改善冠状动脉旁路移植管的局部血流动力学，降低血管再狭窄的发生机率，研究一种可以避免血管再狭窄的双移植管搭桥方式。方法 利用有限元分析方法，对传统模型和双移植管搭桥模型进行血流动力学模拟仿真，计算缝合区附近的流场、壁面切应力等血流动力学因素的分布情况。结果 该双移植管搭桥具有较好的血流动力学分布，明显改善了主搭桥血管与冠状动脉缝合处的血流动力学参数，消除了该部位的涡流和流动停滞点，提高了底面的壁面切应力数值。在辅助搭桥血管与冠状动脉缝合处涡流区长度仅3 mm，与原主搭桥血管缝合处的涡流长度4.5 mm相比明显减小。辅助搭桥管分流了约36%的血液，只有约64%的血液流过了主搭桥管。结论 该双移植管搭桥有助于减小内膜增生的发生机率。

Objective In order to improve the local hemodynamics of coronary artery bypass graft and reduce the incidence of restenosis, a double-bypass-graft design was proposed to alleviate artery stenosis. Methods Based on finite element method, the hemodynamics of the conventional bypass graft model and the double-bypass-graft model was adopted for numerical simulation. The distributions of hemodynamics such as flow field and wall shear stress in the vicinity of anastomosis were calculated. Results This new design provided better hemodynamics near the main anastomosis region, eliminated the vortex and flow stagnation, and increased the wall shear stress at the artery floor. The axial length of vortex near the assistant bypass graft by this new design was only 3 mm, which was shorter than that of 4.5 mm in the conventional design. Nearly 36% of the total blood was directed into the assistant bypass graft. Conclusions The new design could help to reduce the incidence of intimal hyperplasia.

国家自然科学基金资助项目（11172016,10872013），北京市自然科学基金资助项目（3092005），北京市自然科学基金重点项目(KZ201210005006)， 高等学校博士学科点专项科研基金资助课题(20111103110012)