Which diameter and angle rule provides optimal flow patterns in a coronary bifurcation?
Which diameter and angle rule provides optimal flow patterns in a coronary bifurcation?
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DOI：
10.1016/j.jbiomech.2012.01.033
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发表时间：
2012-04-30
影响因子：
2.4
通讯作者：
Kassab GS
中科院分区：
文献类型：
--
作者：
Huo Y;Finet G;Lefevre T;Louvard Y;Moussa I;Kassab GS
心外膜冠状动脉分支的分支角度和直径比是决定动脉粥样硬化形成的两个重要因素。默里的立方直径法和分叉角已被假定为通过分叉产生最佳流量。相比之下，我们最近展示了一个 直径法（HK直径模型），基于整个树结构中的最小能量假设。在这里，我们推导出对应于HK直径模型的分叉角规则，并严格评估通过HK和墨累型分叉的流线流。冠状动脉模型的分叉比Murray模型更符合HK直径模型和角度规则。采用有限元模型研究了不同类型冠状动脉分叉处的流动模式。采用ComboWire测量了进气速度和压力边界条件。与HK型分叉相比，Murray型分叉的Y型分叉降低了动脉粥样硬化易发区的壁面剪切应力WSS（10%-40%），并增加了动脉粥样硬化易发区的振荡剪切指数OSI。HK型分叉被发现具有更优的流动模式（即，更高的WSS和更低的OSI）比传统上被认为是优化的Murray型分叉。这项研究对经皮冠状动脉介入治疗中分叉角度和直径的变化有意义。
The branching angle and diameter ratio in epicardial coronary artery bifurcations are two important determinants of atherogenesis. Murray’s cubed diameter law and bifurcation angle have been assumed to yield optimal flows through a bifurcation. In contrast, we have recently shown a diameter law (HK diameter model), based on minimum energy hypothesis in an entire tree structure. Here, we derive a bifurcation angle rule corresponding to the HK diameter model and critically evaluate the streamline flow through HK and Murray-type bifurcations. The bifurcations from coronary casts were found to obey the HK diameter model and angle rule much more than Murray’s model. A finite element model was used to investigate flow patterns for coronary artery bifurcations of various types. The inlet velocity and pressure boundary conditions were measured by ComboWire. Y-bifurcation of Murray type decreased wall shear stress-WSS (10%–40%) and created an increased oscillatory shear index-OSI in atherosclerosis-prone regions as compared with HK-type bifurcations. The HK-type bifurcations were found to have more optimal flow patterns (i.e., higher WSS and lower OSI) than Murray-type bifurcations which have been traditionally believed to be optimized. This study has implications for changes in bifurcation angles and diameters in percutaneous coronary intervention.