Affiliations: Department of Mechanical Engineering, Dublin Institute of Technology, Dublin, Ireland
Note: [] Address for correspondence: J.B. Murphy, Department of Mechanical Engineering, Dublin Institute of Technology, Dublin, Ireland. Tel.: +353 1 402 3963; Fax: +353 1 402 3999; E-mail: jonathan.murphy@dit.ie.
Abstract: The benefit of coronary stent implantation is reduced by excessive intimal hyperplasia which re-narrows the artery and the prevention of which is still a primary concern for clinicians. Abnormal hemodynamics create non-physiological viscous stress on the artery wall, one of the root causes of intimal hyperplasia following stent implantation. A methodology to comprehensively evaluate the viscous stress on the artery wall following stent implantation would be useful to evaluate a stent's hemodynamic performance. The proposed methodology employs 3D computational fluid dynamics, the variables wall shear stress (WSS), WSS gradient (WSSG), WSS angle gradient (WSSAG) and a statistical analysis to evaluate the viscous stress. The methodology is demonstrated and compared to a commonly used “threshold technique” for evaluating a stent's hemodynamic performance. It is demonstrated that the threshold technique is not adequate to fully analyse the viscous stress on the artery wall and can even be misleading. Furthermore, all three of the aforementioned variables should be considered as each provides a different perspective on the abnormalities that can arise in the arterial viscous stress. The hemodynamic performance of a stent can be assessed more comprehensively than with previously used methods by examining the arterial viscous stresses using the proposed methodology.
