Computational Simulations of Provisional Stenting of a Diseased Coronary Artery Bifurcation Model

Henry Y Chen,Yves Louvard,Yiannis S Chatzizisis,Ghassan S Kassab

doi:10.1038/s41598-020-66777-1

Abstract

Although stenting of non-branched arterial segments has acceptable clinical outcomes, in-stent restenosis (ISR) and stent thrombosis remain clinically significant issues for vascular bifurcations (15–28% restenosis). Local fluid and solid stresses appear to play an important role in restenosis and thrombosis. The combined role of wall shear stress (WSS) and circumferential wall stresses (CWS) is unclear in the case of stenting at vascular bifurcations. Using numerical simulations, we computed the fluid shear, solid stresses and the stress ratio at the the bifurcation region. Stenting of main vessel increased the maximum CWS in the the side branch (SB), resulting in a nearly two-fold increase of stress ratio in the SB compared to the MB (5.1 × 105 vs. 9.2 × 105). The existence of plaque decreased WSS and increased CWS near the carina, increasing the stress ratio at the SB. The changes of stress ratio were highly consistent with clinical data on bifurcation stenting. Fluid dynamics and solids mechanics should be considered in planning of stenting for a specific bifurcation, as their combined biomechanical effect may play an important role in stent restenosis and thrombosis.

Highlights

Stenting of non-branched vessels has shown acceptable safety and efficacy, bifurcation stenting is associated with higher rates of adverse events and remains a challenge among the interventional cardiology community
The Reynolds numbers in the current study was an order of magnitude smaller than the Reynolds number for transition to turbulence (>2,300)
The simulations found that stenting of bifurcation with plaque resulted in higher stress ratio than that of without plaque (4.7 × 105 vs. 7.9 × 105) (Fig. 3C)

Summary

Introduction

Stenting of non-branched vessels has shown acceptable safety and efficacy, bifurcation stenting is associated with higher rates of adverse events and remains a challenge among the interventional cardiology community. Risks of ISR and late stent thrombosis are elevated for bifurcation lesions, resulting in higher complication rates and more frequent re-intervention[1,2,3,4]. Computational simulation is a very useful tool to evaluate the local biomechanical stresses[5,6]. Computational fluid dynamics (CFD) has been known as a useful tool to evaluate the endothelial shear stress in blood vessels[6,9]. The objective of this study is to understand the fluid and solid mechanical disturbances caused by provisional stenting in bifurcations with the presence of plaque structure. These local biomechanical perturbations may affect ISR as higher stress ratio correlates with higher restenosis rates. We compared the simulations results with relevant clinical data to study the potential relationship

Objectives

Results

Conclusion