Open Access

ARTICLE

The Study of the Graft Hemodynamics with Different Instant Patency in Coronary Artery Bypassing Grafting

by Zhou Zhao¹, Boyan Mao², Youjun Liu², Haisheng Yang², Yu Chen¹

1 Cardiac Surgery Department, Peking University People’s Hospital.11th. Ave. Xizhimen, Beijing, China.
2 College of Life Science and Bio-engineering, Beijing University of Technology. No. 100 Pingleyuan, Chaoyang District, Beijing, China.

*Corresponding Author: Yu Chen. Email: . & These authors contributed equally to this paper.

(This article belongs to the Special Issue: Innovations and Current Trends in Computational Cardiovascular Modeling: Molecular, Cellular, Tissue and Organ Biomechanics with Clinical Applications)

Computer Modeling in Engineering & Sciences 2018, 116(2), 229-245. https://doi.org/10.31614/cmes.2018.04192

Abstract

In coronary artery bypass grafting (CABG), graft’s poor instant patency may lead to an abnormal hemodynamic environment in anastomosis, which could further cause graft failure after the surgery. This paper investigates the graft hemodynamics with different instant patency, and explores its effect on graft postoperative efficiency. Six CABG 0D/3D coupling multi-scale models which used left internal mammary artery (LIMA) and saphenous vein (SVG) as grafts were constructed. Different types of grafts were examined in the models, including normal grafts, grafts with competitive flow and grafts with anastomotic stenosis. Simulation results indicated that comparing with SVG grafts, there was a greater difference between normal LIMA graft and non-patent LIMA graft. Also, the backflow occurred even in LIMA systolic flow. The wall shear stress (WSS) in the graft of the competitive flow LIMA model had an appreciable decrease comparing with the normal graft. In addition, the WSS in the stenosis region of the anastomotic stenosis LIMA model was much higher than its adjacent regions. In contrast, the WSS distributions in the SVG models were much smoother than in the LIMA models. For oscillatory shear index (OSI), there was little difference between normal LIMA and SVG. But when the graft had competitive flow or anastomotic stenosis, much higher OSI occurred in some regions in LIMA than SVG. There are significant differences in hemodynamics between normal grafts and non-patent grafts both in LIMA and SVG. The hemodynamic environment in a normal LIMA is better than that in a normal SVG. However, in the situation of the two types of non-patent grafts, the hemodynamics of SVG is better than LIMA.

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Keywords

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