Document Type : Technical note

Authors

1 Associate Professor, School of Chemical and Petroleum Engineering, Sharif University of Technology

2 Ph.D Candidate, Department of Biomechanics, School of Mechanical Engineering, Sahand University of Technology

3 Associate Professor, Department of Biomechanics, School of Mechanical Engineering, Sahand University of Technology

4 Ph.D Candidate, School of Chemical and Petroleum Engineering, Sharif University of Technology

10.22041/ijbme.2010.13378

Abstract

This study aimed to simulate three dimensional pulsatile Newtonian blood flow in End-to-Side anastomosis of Aorta-coronary bypass using ascending aorta velocity flow wave as graft inlet and left anterior descending coronary artery (LAD) velocity flow wave as coronary inlet for 50% symmetric stenosis. We have supposed that LAD walls were rigid and had no spatial mobility due to heart beats. In order to investigate the graft angles effects on blood flow, especially on the wall shear stress magnitudes, 20, 30 and 40 degrees graft angles were used. Using ascending aorta and LAD pulses simultaneously as boundary conditions for the first time is one of the important features of this study because already these boundary conditions have not been used simultaneously. We considered prograde flow effects. Appearance of recirculation flows in various degrees of grafting angles, existence of secondary flows and increased in their effects specially in pulses deceleration phase, existence of double core helical flows and increase in their intensify specially at the systole peak and the rise in the spatial wall shear stress gradient by increasing in the graft angle are some of important results of this study. Finally, according to our assumptions we suggest 20 to 30 degrees as desired angles for grafting.

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[1]     Stephanie M. K., David A. V., The Effect of Proximal Artery Flow on the Homodynamics at the Distal Anastomosis of a Vascular Bypass Graft: Computational Study; Departments of Bioeng. And Surg. University of Pittsburgh, 2001.
[2]     Hartman C. W., Kong Y., Margolis J. R., Aortocoronary Bypass Surgery: Correlation of Angiographic, Symptomatic and Functional Improvement at 1 Year, Am. J. Cardiol. 1976; 37: 352- 357.
[3]     Imparato A. M., Intimal and Neointimal Fibrous Proliferation Causing Failure of Arterial Reconstruction; Surgery 1972; 74: 1007-1017.
[4]     Bassiouny H. S., White S., Glagov S., Anastomotic Intimal Hyperplasia: Mechanical Injury or flow induced; J. Vasc. Surg. 1992; 15: 708-717.
[5]     Sotturai V. S., Yao J. S. T., Baston R. C., Sue S. L., Jones R., Nakamura Y. A., Distal Anastomotic Intimal Hyperplasia: Histopathologic Character and Biogenesis; Ann. Vasc. Surg. 1989; 3: 26-33.
[6]     Grondin C. M., Late Results of Coronary Artery Grafting: Is There a Flag on the Field? J. of Thorac. Cardiovasc. Surg. 1984; 87: 161-166.
[7]     Giddens D. P., Zarins C. K., Glagov S., The Role of Fluid Mechanics in the Localization and Detection of Atherosclerosis; ASME J. of Biomech. Eng. 1993; 115: 558-594.
[8]     Caro C. G., Fitzgerald J. M., Schroter R. C., Atheroma and Arterial Wall Shear Observations, Correlation and Proposal of a Shear Dependant Mass Transfer Mechanism for Atherosclerosis, Proc. R. Soc. 1971; 177: 109-159.
[9]     Pietrabissa R., Inzoli F., Simulation Study of Fluid Dynamics of Aorta-Coronary Bypass; J. of Biomech. Eng. Sep 1990; 12 (5): 419-424.
[10] Inzoli F., Migliavacca F., Pennati G., Numerical Analysis of Steady Flow in Aorto-Coronary Bypass 3-D Model, J of Biomechanical Eng., 1996; 118 (2): 172-9.
[11] Yubo F., Wentao J., Yuanwen Z., Jinchuan L., Junkai C., Xiaoyan D., Numerical Simulation of Pulsatile non- Newtonian Flow in the Carotid Artery Bifurcation, Acta Mech Sin. 2009; 25: 249–255.
[12] Barbara M., Johnston P.R., Johnston S.C., David, K., Non-Newtonian Blood Flow in Human Right Coronary Arteries, Transient Simulations. J. Biomech, 2006; 39: 1116–1128.
[13] Chen, J., Lu, X.Y., Numerical Investigation of the Non- Newtonian Pulsatile Blood Flow in a Bifurcation Model with a Non-Planar Branch. J. Biomech., 2006; 39, 818– 832.
[14] Hernán A.G., Nelson, O.M., On Predicting Unsteady Non-Newtonian Blood Flow, Appl. Math. Comput., 2005; 170: 909 923.
[15] Dzwinel W., Yuen D., Boryczko K., Bridging Diverse Physical Scales with the Discrete-Particle Paradigm in Modeling Colloidal Dynamics with Mesoscopic Features, Chem Eng Sci., 2006; 61: 2169–85.
[16] Tu C., Deville M., Dheur L., Vanderschuren L., Finite element simulation of pulsatile flow through arterial stenosis; J. Biomechanics, 1992; 25 (10): 1141-1152.
[17] Lee K. W., Xu X. Y., Modeling of Flow and Wall Behavior in a Mildly Stenosed Tube, J. of Medical Engineering & Physics, 2002; 24: 575-586.
[18] احمدلوی داراب مجید، شبیه‌سازی جریان پالسی خون در عروق کرونری بای‌پس شده و بررسی دلایل احتمالی انسداد مجدد، پایان‌نامه کارشناسی ارشد، دانشگاه صنعتی شریف، دانشکده مهندسی شیمی، بهار 1383.