Numerical Simulation of Physiological Blood Flow in 2-way Coronary Artery Bypass Grafts
The Coronary Artery Bypass Graft (CABG) yields excellent results and remains the modern standard of care for treatment of occlusive disease in the cardiovascular system. However, the development of anastomotic Intimal Hyperplasia (IH) and restenosis can compromise the medium-and-long term effects of the CABG. This problem can be correlated with the geometric configuration and hemodynamics of the bypass graft. A novel geometric configuration was proposed for the CABG with two symmetrically implanted grafts for the purpose of improving the hemodynamics. Physiological blood flows in two models of bypass grafts were simulated using numerical methods. One model was for the conventional bypass configuration with a single graft (1-way model); the other model was for the proposed bypass configuration with two grafts (2-way model). The temporal and spatial distributions of hemodynamics, such as flow patterns and Wall Shear Stress (WSS) in the vicinity of the distal anastomoses, were analyzed and compared. Calculation results showed that the 2-way model possessed favorable hemodynamics with uniform longitudinal flow patterns and WSS distributions, which could decrease the probability of restenosis and improve the effect of the surgical treatment. Concerning the limitations of the 2-way bypass grafts, it is necessary to perform animal experiments to verify the viability of this novel idea for the CABG.
Keywordsanastomosis CABG cardiovascular system geometric configuration hemodynamics intimal hyperplasia restenosis
Unable to display preview. Download preview PDF.
- Sottiurai, V.S., Yao, J.S.T., Batson, R.C., Sue, S.L. and Jones, R.: Nakamura YA. Distal anastomotic Intimal Hyperplasia: Histopathologic Character and Biogenesis, Ann. Vasc. Surg. 24 (1989), 711–722.Google Scholar
- Perktold, K., Tatzl, H. and Rappitsch, G.: Flow Dynamic Effect of the Anastomotic Angle: A Numerical Study of Pulsatile Flow in Vascular Graft Anastomoses Models, Technol. Health. Care. 1 (1994), 197–207.Google Scholar
- Deplano, V., Bertolotti, C. and Boiron, C.: Numerical Simulations of Unsteady Flows in a Stenosed Coronary Bypass Graft, Med. Biol. Eng. Comp. 39 (2001), 488–499.Google Scholar
- Noori, N., Scherer, R., Perktold, K., Czerny, M., Karner, G., Trubel, M., Polterauer, P. and Schima, H.: Blood Flow in Distal End-to-Side Anastomoses with PTFE and a Venous Patch: Results of an in vitro Flow Visualisation Study, Eur. J. Vasc. Endovasc. Surg. 18 (1999), 191–200.CrossRefPubMedGoogle Scholar
- Liu, Y., Qiao, A. and Gao, S.: Physiological Flow Simulation Of Coronary Bypass Graft. Proceedings of the World Congress on Medical Physics and Biomedical Engineering, Aug 24–29, 2003, Sydney, Australia, [CD-ROM] ISBN 1877040142, Paper No. 1840.Google Scholar
- Liu, Y., Qiao, A. and Zhu, H.: Haemodynamics Simulation for Carotid Bifurcation, Chinese J. Biomed. Eng. 12 (2003), 17–24.Google Scholar
- Qiao, A.K., Zeng, Y.J. and Xu, X.H.: Numerical Simulations of Stenosed Femoral Artery with Symmetric 2-Way Bypass Graft, Bio-Med. Mater. Eng. 14 (2004), 167–174.Google Scholar
- White, S.S., Zarins, C.K., Giddens, D.P., Bassiouny, H., Loth, F., Jones, S.A. and Glagov, S.: Hemodynamic Patterns in Two Models of End-to-Side Vascular Graft Anastomoses: Effects of Pulsatility, Flow Division, Reynolds Number, and Hood Length, J. Biomech. Eng. 115 (1993), 104–111.PubMedGoogle Scholar
- Qiao, A., Liu, Y. and Guo, Z.: Wall Shear Stresses in Small and Large 2-Way Bypass Grafts, Med. Eng. Phys., in press.Google Scholar