Pinho N, Sousa L C, Castro C F, António C C, Carvalho M, Ferreira W, Ladeiras-Lopes R, Ferreira N D, Braga P, Bettencourt N, Pinto S I S
Institute of Science and Innovation in Mechanical and Industrial Engineering (LAETA-INEGI), Rua Dr. Roberto Frias, 400, 4200-465, Porto, Portugal.
Engineering Faculty, University of Porto, Rua Dr. Roberto Frias, s/n, 4200-465, Porto, Portugal.
Cardiovasc Eng Technol. 2019 Jun;10(2):257-270. doi: 10.1007/s13239-019-00403-8. Epub 2019 Feb 6.
Coronary artery geometry can have a significant impact in the hemodynamic behavior of coronary blood flow, influencing atherosclerotic plaque formation. The present work focuses on, through a statistical study, the connection between several geometric parameters of the right coronary artery-ostium cross-sectional area, angles between the common trunk and the side-branches, tortuosity, curvature and cross-sectional area in each side-branch-and their influence on hemodynamic descriptors. Parameters such as low wall shear stress and local disturbed flow, which are associated with atherosclerosis formation, were analysed.
Computed tomography images of ten healthy individuals were selected to reconstruct in vivo three-dimensional models of right coronary arteries. Blood flow was simulated through a compliant model with realistic boundary conditions. Calculated hemodynamic descriptors values were correlated with the geometric parameters using the Pearson correlation coefficient (r) and the p value.
The strongest correlations were found in the middle and distal segments of the right coronary artery. A decrease in the ostium area promotes a decrease in the WSS magnitude from the proximal to the distal segment (r = 0.82). Very strong correlations (r > 0.90) were achieved between geometric parameters (cross-sectional area, angle, tortuosity) of the right-ventricular branch and the wall shear stress magnitude in the middle and distal segments.
Low values of tortuosity, smaller cross-sectional area and higher angle of the right-ventricular branch leads to a hemodynamic behavior more propitious to atherosclerosis formation, within the study cases. The right-ventricular branch seems to have the highest influence in the hemodynamic behavior of the right coronary artery.
冠状动脉几何形状可对冠状动脉血流的血流动力学行为产生重大影响，进而影响动脉粥样硬化斑块的形成。本研究通过统计分析，聚焦于右冠状动脉的几个几何参数（即窦口横截面积、主干与侧支之间的夹角、扭曲度、曲率以及每个侧支的横截面积）之间的联系，以及它们对血流动力学描述符的影响。分析了与动脉粥样硬化形成相关的参数，如低壁面切应力和局部紊乱血流。
选取10名健康个体的计算机断层扫描图像，以重建右冠状动脉的体内三维模型。通过具有实际边界条件的顺应性模型模拟血流。使用皮尔逊相关系数（r）和p值将计算得到的血流动力学描述符值与几何参数进行关联。
在右冠状动脉的中段和远端发现了最强的相关性。窦口面积减小会促使从近端到远端节段的壁面切应力大小降低（r = 0.82）。右心室分支的几何参数（横截面积、角度、扭曲度）与中段和远端节段的壁面切应力大小之间实现了非常强的相关性（r > 0.90）。
在本研究案例中，右心室分支的低扭曲度、较小横截面积和较大角度会导致更有利于动脉粥样硬化形成的血流动力学行为。右心室分支似乎对右冠状动脉的血流动力学行为影响最大。
