Geometry of the carotid bifurcation predicts its exposure to disturbed flow
Geometry of the carotid bifurcation predicts its exposure to disturbed flow
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DOI：
10.1161/strokeaha.107.510644
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发表时间：
2008-08-01
期刊：
影响因子：
8.3
通讯作者：
Steinman, David A.
中科院分区：
文献类型：
--
作者：
Lee, Sang-Wook;Antiga, Luca;Steinman, David A.
背景和目的-某些血管可能存在所谓的动脉粥样硬化几何风险，这是基于以下假设：扰动血流存在广泛的个体间差异，以及扰动血流与管腔几何形状之间存在直接关系。在测试这些往往隐含的假设，本研究的目的是确定是否在动脉粥样硬化的局部危险因素的调查确实可以依赖于代理的几何标记的干扰flow.Methods -计算流体动力学模拟颈动脉分叉的几何形状来自MRI的25名年轻人。扰动流被量化为暴露于超出客观定义阈值的低和振荡剪切的表面积。个体间的扰动流的变化与成像和几何重建的不确定性的影响进行了上下文。扰动流和各种几何因素之间的关系进行了测试，通过多元回归。多元回归分析显示，扰动流与近端面积比（β约为0.5）和分叉弯曲度（β约为-0.4）之间存在显著（P < 0.002）关系，但与分叉角度、平面度或远端面积比无关。这些研究结果被证明是不敏感的流动条件的假设和干扰流指标和thresholds.Conclusions的选择-某些几何特征的年轻成人颈动脉分叉是强大的替代标记，其暴露于干扰流。因此，考虑对动脉粥样硬化的局部危险因素进行大规模回顾性或前瞻性成像研究可能是合理的，而不需要耗时且昂贵的血流成像或CFD研究。
Background and Purpose - That certain vessels might be at so-called geometric risk of atherosclerosis rests on assumptions of wide interindividual variations in disturbed flow and of a direct relationship between disturbed flow and lumen geometry. In testing these often-implicit assumptions, the present study aimed to determine whether investigations of local risk factors in atherosclerosis can indeed rely on surrogate geometric markers of disturbed flow.Methods - Computational fluid dynamics simulations were performed on carotid bifurcation geometries derived from MRI of 25 young adults. Disturbed flow was quantified as the surface area exposed to low and oscillatory shear beyond objectively-defined thresholds. Interindividual variations in disturbed flow were contextualized with respect to effects of uncertainties in imaging and geometric reconstruction. Relationships between disturbed flow and various geometric factors were tested via multiple regression.Results - Relatively wide variations in disturbed flow were observed among the 50 vessels. Multiple regression revealed a significant (P < 0.002) relationship between disturbed flow and both proximal area ratio (beta approximate to 0.5) and bifurcation tortuosity (beta approximate to-0.4), but not bifurcation angle, planarity, or distal area ratio. These findings were shown to be insensitive to assumptions about the flow conditions and to the choice of disturbed flow indicator and threshold.Conclusions - Certain geometric features of the young adult carotid bifurcation are robust surrogate markers of its exposure to disturbed flow. It may therefore be reasonable to consider large-scale retrospective or prospective imaging studies of local risk factors for atherosclerosis without the need for time-consuming and expensive flow imaging or CFD studies.