Hemodynamic alternations following stent deployment and post-dilation in a heavily calcified coronary artery: In silico and ex-vivo approaches

Peshala T Gamage; Pengfei Dong; Juhwan Lee; Yazan Gharaibeh; Vladislav N Zimin; Luis A P Dallan; Hiram G Bezerra; David L Wilson; Linxia Gu

doi:10.1016/j.compbiomed.2021.104962

Hemodynamic alternations following stent deployment and post-dilation in a heavily calcified coronary artery: In silico and ex-vivo approaches

Comput Biol Med. 2021 Dec:139:104962. doi: 10.1016/j.compbiomed.2021.104962. Epub 2021 Oct 21.

Authors

Peshala T Gamage¹, Pengfei Dong², Juhwan Lee³, Yazan Gharaibeh³, Vladislav N Zimin⁴, Luis A P Dallan⁴, Hiram G Bezerra⁵, David L Wilson³, Linxia Gu⁶

Affiliations

¹ Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA.
² Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. Electronic address: pdong@fit.edu.
³ Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44106, USA.
⁴ Cardiovascular Imaging Core Laboratory, Harrington Heart & Vascular Institute, University Hospitals Cleveland Medical Center, Cleveland, OH, 44106, USA.
⁵ Interventional Cardiology Center, Heart and Vascular Institute, The University of South Florida, Tampa, FL, 33606, USA.
⁶ Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, 32901, USA. Electronic address: gul@fit.edu.

Abstract

In this work, hemodynamic alterations in a patient-specific, heavily calcified coronary artery following stent deployment and post-dilations are quantified using in silico and ex-vivo approaches. Three-dimensional artery models were reconstructed from OCT images. Stent deployment and post-dilation with various inflation pressures were performed through both the finite element method (FEM) and ex vivo experiments. Results from FEM agreed very well with the ex-vivo measurements, interms of lumen areas, stent underexpansion, and strut malapposition. In addition, computational fluid dynamics (CFD) simulations were performed to delineate the hemodynamic alterations after stent deployment and post-dilations. A pressure time history at the inlet and a lumped parameter model (LPM) at the outlet were adopted to mimic the aortic pressure and the distal arterial tree, respectively. The pressure drop across the lesion, pertaining to the clinical measure of instantaneous wave-free flow ratio (iFR), was investigated. Results have shown that post-dilations are necessary for the lumen gain as well as the hemodynamic restoration towards hemostasis. Malapposed struts induced much higher shear rate, flow disturbances and lower time-averaged wall shear stress (TAWSS) around struts. Post-dilations mitigated the strut malapposition, and thus the shear rate. Moreover, stenting induced larger area of low TAWSS (<0.4 Pa) and lager volume of high shear rate (>2000 s^-1), indicating higher risks of in-stent restenosis (ISR) and stent thrombosis (ST), respectively. Oscillatory shear index (OSI) and relative residence time (RRT) indicated the wall regions more prone to ISR are located near the malapposed stent struts.

Keywords: Calcified artery; Computational fluid dynamics (CFD); Finite element method (FEM); Hemodynamics; Optical coherence tomography (OCT); Oscillatory shear index; Percutaneous coronary intervention (PCI); Post-dilation; Relative residence time; Restenosis; Shear rate; Stent expansion; Stent thrombosis; Wall shear stress.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Computer Simulation
Coronary Vessels* / diagnostic imaging
Coronary Vessels* / surgery
Dilatation
Hemodynamics
Humans
Stents
Tomography, Optical Coherence*

Grants and funding

R01 HL143484/HL/NHLBI NIH HHS/United States