Link between deviations from Murray's Law and occurrence of low wall shear stress regions in the left coronary artery

• Type: Article in International Scientific Journal
• Date: 2016

Authors

E. Doutel (Author) FEUP; S. I. S. Pinto (Author) FEUP; J. B. L. M. Campos (Author) FEUP; J. M Miranda (Author) FEUP

Journal

Title: Journal of Theoretical Biology

Vol. 402

Pages: 89-99

ISSN: 0022-5193

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 8 Citations

Scientific classification

CORDIS: Technological sciences > Engineering > Mechanical engineering

FOS: Engineering and technology > Mechanical engineering

Associated Projects

LEPAE/CEFT - RL2 - (Bio) Chemical Engineering: Multi-Scale Approaches for Sustainable Environment and Health

PTDC/EME-MFE/102974/2008 - Estudo numérico e experimental do escoamento de sangue no interior de stents implantados em artérias

UI0532 - PROJECTO ESTRATÉGICO - UI 532 - 2013-2014

Other information

Authenticus ID: P-00K-EWV

DOI: 10.1016/j.jtbi.2016.04.038

Abstract (EN): Murray developed two laws for the geometry of bifurcations in the circulatory system. Based on the principle of energy minimization, Murray found restrictions for the relation between the diameters and also between the angles of the branches. It is known that bifurcations are prone to the development of atherosclerosis, in regions associated to low wall shear stresses (WSS) and high oscillatory shear index (OSI). These indicators (size of low WSS regions, size of high OSI regions and size of high helicity regions) were evaluated in this work. All of them were normalized by the size of the outflow branches. The relation between Murray¿s laws and the size of low WSS regions was analysed in detail. It was found that the main factor leading to large regions of low WSS is the so called expansion ratio, a relation between the cross section areas of the outflow branches and the cross section area of the main branch. Large regions of low WSS appear for high expansion ratios. Furthermore, the size of low WSS regions is independent of the ratio between the diameters of the outflow branches. Since the expansion ratio in bifurcations following Murray¿s law is kept in a small range (1 and 1.25), all of them have regions of low WSS with similar size. However, the expansion ratio is not small enough to completely prevent regions with low WSS values and, therefore, Murray¿s law does not lead to atherosclerosis minimization. A study on the effect of the angulation of the bifurcation suggests that the Murray¿s law for the angles does not minimize the size of low WSS regions.

Language: English

Type (Professor's evaluation): Scientific