Halevi Rotem, Hamdan Ashraf, Marom Gil, Lavon Karin, Ben-Zekry Sagit, Raanani Ehud, Bluestein Danny, Haj-Ali Rami
The Fleischman Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, 69978, Tel Aviv, Ramat Aviv, Israel.
Nuclear Cardiology Unit, Heart Institute, Chaim Sheba Medical Center, 52621, Tel Hashomer, Israel.
Med Biol Eng Comput. 2016 Nov;54(11):1683-1694. doi: 10.1007/s11517-016-1458-0. Epub 2016 Feb 23.
Calcific aortic valve disease (CAVD) is characterized by calcification accumulation and thickening of the aortic valve cusps, leading to stenosis. The importance of fluid flow shear stress in the initiation and regulation of CAVD progression is well known and has been studied recently using fluid-structure interaction (FSI) models. While cusp calcifications are three-dimensional (3D) masses, previously published FSI models have represented them as either stiffened or thickened two-dimensional (2D) cusps. This study investigates the hemodynamic effect of these calcifications employing FSI models using 3D patient-specific calcification masses. A new reverse calcification technique (RCT) is used for modeling different stages of calcification growth based on the spatial distribution of calcification density. The RCT is applied to generate the 3D calcification deposits reconstructed from a patient-specific CT scans. Our results showed that consideration of 3D calcification deposits led to both higher fluid shear stresses and unique fluid shear stress distribution on the aortic side of the cusps that may have an impact on the calcification growth rate. However, the flow did not seem to affect the geometry of the calcification during the growth phase.
钙化性主动脉瓣疾病(CAVD)的特征是主动脉瓣叶钙化积聚和增厚,导致狭窄。血流剪切应力在CAVD进展的起始和调节中的重要性是众所周知的,并且最近已经使用流固耦合(FSI)模型进行了研究。虽然瓣叶钙化是三维(3D)肿块,但先前发表的FSI模型将它们表示为硬化或增厚的二维(2D)瓣叶。本研究使用基于3D患者特异性钙化肿块的FSI模型研究这些钙化的血流动力学效应。一种新的逆向钙化技术(RCT)用于根据钙化密度的空间分布对钙化生长的不同阶段进行建模。RCT应用于生成从患者特异性CT扫描重建的3D钙化沉积物。我们的结果表明,考虑3D钙化沉积物会导致瓣叶主动脉侧更高的流体剪切应力和独特的流体剪切应力分布,这可能会影响钙化生长速率。然而,在生长阶段,血流似乎并未影响钙化的几何形状。