摘要
在传统股动脉搭桥术中,由于下游缝合区采用“端对侧”的“单路搭桥”缝合方式,移植管中血流会对缝合区底面产生很大冲击,引起局部血流动力学急剧变化,并可能因此而导致血管再狭窄和手术失败。由于缝合区几何结构的不对称必然导致流场的不均匀,本研究提出了“对称双路搭桥”的构想以图改善血流动力学。本研究对“单路”和“对称双路”两种连接模型中的血液流动进行了数值模拟。两种模型利用相同的几何参数进行建模,并采用了相同的边界条件。数值模拟结果包括流场、壁面切应力及其梯度等血流动力学参数。研究表明,“对称双路”模型比“单路”模型具有较大的纵向速度、较小的二次流、较均匀的壁面切应力等。因此,“对称双路”搭桥模型具有更好的血流动力学,可以减少股动脉搭桥术后内膜增生和再狭窄的可能性。
In the conventional femoral bypass surgery, the end-to-side 1-way junction is employed at the distal anastomosis, and the blood flow from the graft strongly strikes on the floor of the anastomosis, that results in the violent changes of hemodynamics and leads to restenosis and surgery failure. Based on the fact that the asymmetric geometry of anastomosis inevitably bring about the nonuniform flow field, this paper proposed an idea of symmetric 2-way bypass graft to improve the hemodynamics. The numerical simulation of blood flow in the 1-way and 2-way models was performed. The two models were constructed with identical geometry parameters, and identical boundary conditions were employed. The results of the numerical simulation include flow patterns, wall shear stresses and wall shear stress gradients. It was indicated that the symmetric 2-way model exhibited larger longitudinal velocity, smaller secondary flow, more uniform wall shear stresses than the 1-way model, Hence, the symmetric 2-way bypass graft model was considered more favorable hemodynamics and could decrease the probability of intimal thickening and restenosis after the femoral bypassing surgery.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2006年第2期211-218,共8页
Chinese Journal of Biomedical Engineering
基金
北京市教委项目(KM2004100050007)
关键词
生物流体力学
搭桥
壁面切应力
再狭窄
数值模拟
Bio-fluid mechanics
bypass
wall shear stress
restenosis
numerical simulation
