Usefulness and limitations of computational models in aortic disease risk stratification
Usefulness and limitations of computational models in aortic disease risk stratification
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DOI：
10.1016/j.jvs.2010.05.117
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发表时间：
2010-12-01
影响因子：
4.3
通讯作者：
Labrosse, Michel R.
中科院分区：
文献类型：
--
作者：
Beller, Carsten J.;Gebhard, Martha M.;Labrosse, Michel R.
目的：在主动脉疾病（如动脉瘤和主动脉夹层）的风险分层中，直径是一个参数，其对平均主动脉壁应力的影响直接由拉普拉斯定律描述。可以使用更先进的力学模型，并且可以产生额外的信息，例如透壁应力分布。然后出现的问题，如何细化模型需要为临床医生提供实际的help.Methods：两套有限元模型。使用简化的主动脉模型探索直径、材料刚度、纵向拉伸、血压、壁厚和血管曲率的相对作用，以与拉普拉斯定律进行比较。的材料特性的非线性和残余应力的跨壁应力分布的影响进行了研究，使用先进的主动脉模型，包括最近的实验结果在老年human.Results：的拉普拉斯定律被证实是一个有效的，基本的工具，以评估在主动脉壁的平均壁应力，无论是在圆周方向和纵向方向。然而，简化模型足以表明，如文献中已经报道的，纵向拉伸和血管曲率对壁应力的贡献可能与拉普拉斯定律中包含的参数相同或甚至更强。当使用先进的模型，并引入大的开口角，如在老年受试者中发现的残余应力诱导，跨壁应力梯度被发现与预期相反，最大的应力现在朝向外膜。结果表明，内膜可能会越来越多地屏蔽较高的应力，因为一个人变老，这可能是保护对开始的夹层撕裂在胸aorator.Conclusion：主动脉的生物力学分析可以细化使用越来越详细的计算模型。简化模型可以很容易地改善主动脉壁应力评估中的拉普拉斯定律，因此，可能已经有助于更好地对主动脉疾病进行风险分层。先进的模型也可以提高我们对主动脉疾病发病机制的理解。然而，它们在患者特定背景下的适用性可能受到它们所需的大量输入数据的限制，其中一些可能超出临床医生的范围。（J Vase Surg 2010;52：1572-9.）
Objective: In risk stratification of aortic diseases such as aneurysm and aortic dissection, diameter is one parameter whose influence on the average aortic wall stress is directly described by the Laplace law. More advanced mechanical models can be used and may yield additional information, such as transmural stress distributions. The question then arises of how refined models need to be to provide clinicians with practical help.Methods: Two sets of finite element models were used. The relative roles of diameter, material stiffness, longitudinal stretch, blood pressure, wall thickness, and vessel curvature were explored using simplified aortic models for comparison with the Laplace law. The influences of the material properties nonlinearity and residual stress on the transmural stress distribution were investigated using an advanced aortic model including recent experimental findings in older humans.Results: The Laplace law was confirmed as one effective, basic tool to assess the average wall stress in the aortic wall, both in the circumferential and longitudinal directions. However, the simplified models were sufficient to show that, as already reported in the literature, longitudinal stretch and vessel curvature have potentially equally strong or even stronger contributions to wall stress than the parameters included in the Laplace law. When the advanced model was used, and residual stress induced by large opening angles such as found in older subjects was introduced, the transmural stress gradient was found inverted compared with expectations, with the largest stresses now toward the adventitia. The results suggested that the intima may be increasingly shielded from higher stresses as one gets older, which might be protective against the initiation of dissection tears in the thoracic aorta.Conclusion: Biomechanical analysis of the aorta may be refined by using increasingly detailed computational models. Simplified models can readily improve on the Laplace law in the assessment of aortic wall stress, and as such, may already contribute to better risk stratification of aortic disease. Advanced models may also enhance our understanding of the mechanistic aspects in the pathogenesis of aortic disease. However, their applicability in a patient-specific context may be limited by the large number of input data they require, some of which might stay out of the clinicians' reach. (J Vase Surg 2010;52:1572-9.)