Schwarz Janina C V, van Lier Monique G J T B, van den Wijngaard Jeroen P H M, Siebes Maria, VanBavel Ed
Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
Front Physiol. 2020 Jan 23;10:1611. doi: 10.3389/fphys.2019.01611. eCollection 2019.
Many processes contributing to the functional and structural regulation of the coronary circulation have been identified. A proper understanding of the complex interplay of these processes requires a quantitative systems approach that includes the complexity of the coronary network. The purpose of this study was to provide a detailed quantification of the branching characteristics and local hemodynamics of the human coronary circulation.
The coronary arteries of a human heart were filled post-mortem with fluorescent replica material. The frozen heart was alternately cut and block-face imaged using a high-resolution imaging cryomicrotome. From the resulting 3D reconstruction of the left coronary circulation, topological (node and loop characteristics), topographic (diameters and length of segments), and geometric (position) properties were analyzed, along with predictions of local hemodynamics (pressure and flow).
The reconstructed left coronary tree consisted of 202,184 segments with diameters ranging from 30 μm to 4 mm. Most segments were between 100 μm and 1 mm long. The median segment length was similar for diameters ranging between 75 and 200 μm. 91% of the nodes were bifurcations. These bifurcations were more symmetric and less variable in smaller vessels. Most of the pressure drop occurred in vessels between 200 μm and 1 mm in diameter. Downstream conductance variability affected neither local pressure nor median local flow and added limited extra variation of local flow. The left coronary circulation perfused 358 cm of myocardium. Median perfused volume at a truncation level of 100 to 200 μm was 20 mm with a median perfusion of 5.6 ml/min/g and a high local heterogeneity.
This study provides the branching characteristics and hemodynamic analysis of the left coronary arterial circulation of a human heart. The resulting model can be deployed for further hemodynamic studies at the whole organ and local level.
已确定许多参与冠状动脉循环功能和结构调节的过程。要正确理解这些过程之间的复杂相互作用，需要一种定量系统方法，该方法要考虑冠状动脉网络的复杂性。本研究的目的是详细量化人类冠状动脉循环的分支特征和局部血流动力学。
在人体心脏死后用荧光复制材料填充冠状动脉。使用高分辨率成像冷冻切片机对冷冻心脏进行交替切割并对切面成像。从由此得到的左冠状动脉循环的三维重建中，分析拓扑（节点和环路特征）、地形学（节段直径和长度）和几何（位置）属性，以及局部血流动力学（压力和流量）预测。
重建的左冠状动脉树由202,184个节段组成，直径范围为30μm至4mm。大多数节段长度在100μm至1mm之间。直径在75至200μm之间的节段，其平均节段长度相似。91%的节点为分叉。这些分叉在较小血管中更对称且变化较小。大部分压力降发生在直径为200μm至1mm的血管中。下游传导性变化既不影响局部压力也不影响局部平均流量，且仅增加了局部流量的有限额外变化。左冠状动脉循环灌注358cm的心肌。截断水平为100至200μm时，平均灌注体积为20mm，平均灌注量为5.6ml/min/g，且局部异质性高。
本研究提供了人类心脏左冠状动脉循环的分支特征和血流动力学分析。所得模型可用于在整个器官和局部水平进行进一步的血流动力学研究。
