Large-Scale 3-D Geometric Reconstruction of the Porcine Coronary Arterial Vasculature Based on Detailed Anatomical Data

Abstract

The temporal and spatial distribution of coronary blood flow, pressure, and volume are determined by the branching pattern and three-dimensional (3-D) geometry of the coronary vasculature, and by the mechanics of heart wall and vascular tone. Consequently, a realistic simulation of coronary blood flow requires, as a first step, an accurate representation of the coronary vasculature in a 3-D model of the beating heart. In the present study, a large-scale stochastic reconstruction of the asymmetric coronary arterial trees (right coronary artery, RCA; left anterior descending, LAD; and left circumflex, LCx) of the porcine heart has been carried out to set the stage for future hemodynamic analysis. The model spans the entire coronary arterial tree down to the capillary vessels. The 3-D tree structure was reconstructed initially in rectangular slab geometry by means of global geometrical optimization using parallel simulated annealing (SA) algorithm. The SA optimization was subject to constraints prescribed by previously measured morphometric features of the coronary arterial trees. Subsequently, the reconstructed trees were mapped onto a prolate spheroid geometry of the heart. The transformed geometry was determined through least squares minimization of the related changes in both segments lengths and their angular characteristics. Vessel diameters were assigned based on a novel representation of diameter asymmetry along bifurcations. The reconstructed RCA, LAD and LCx arterial trees show qualitative resemblance to native coronary networks, and their morphological statistics are consistent with the measured data. The present model constitutes the first most extensive reconstruction of the entire coronary arterial system which will serve as a geometric foundation for future studies of flow in an anatomically accurate 3-D coronary vascular model.

A hybrid one-dimensional/Womersley model of pulsatile blood flow in the entire coronary arterial tree

“…Future studies will attempt to Large asymmetric bifurcations show a predilection for atherosclerosis. Such bifurcations have been extensively studied biologically (2,4,11,12,16,26). Here, we include the loss coefficients to consider the loss of energy at a bifurcation in the 1-D model.…”

Spiral Wave Attachment to Millimeter-Sized Obstacles

“…19 Given that the intact myocardium is replete with small structures (eg, blood vessels) that may act as anatomic obstacles, the question arises as to why spiral waves are only occasionally stationary (giving rise to monomorphic tachycardia). According to the reconstruction of the coronary arterial tree by Kaimovitz et al, 20 vessels of order 9 to 11 (diameter 700 m to 3 mm) are confined to the epicardium. Therefore, coronary vessels that would be expected, on the basis of the present study, to be significant attractors (diameter Ͼ0.6 mm) are located mainly along the epicardial surface, and a spiral wave rotating about the vessel would not survive even a single rotation.…”

Relation between branching patterns and perfusion in stochastic generated coronary arterial trees

“…During vascular development, vascular networks remodel into complex networks through dilatation, sprouting, and bridging [5,6,13,15,17]. The large variability in myocardial flow per 100 g tissue that is found indicates variation in anatomical characteristics of the coronary arterial tree [7,16].…”