Multicomponent Mechanical Characterization of Atherosclerotic Human Coronary Arteries: An Experimental and Computational Hybrid Approach

Abstract

Atherosclerotic plaque rupture in coronary arteries, an important trigger of myocardial infarction, is shown to correlate with high levels of pressure-induced mechanical stresses in plaques. Finite element (FE) analyses are commonly used for plaque stress assessment. However, the required information of heterogenous material properties of atherosclerotic coronaries remains to be scarce. In this work, we characterized the component-wise mechanical properties of atherosclerotic human coronary arteries. To achieve this, we performed ex vivo inflation tests on post-mortem human coronary arteries and developed an inverse FE modeling (iFEM) pipeline, which combined high-frequency ultrasound deformation measurements, a high-field magnetic resonance-based artery composition characterization, and a machine learning-based Bayesian optimization (BO) with uniqueness assessment. By using the developed pipeline, 10 cross-sections from five atherosclerotic human coronary arteries were analyzed, and the Yeoh material model constants of the fibrous intima and arterial wall components were determined. This work outlines the developed pipeline and provides the knowledge of non-linear, multicomponent mechanical properties of atherosclerotic human coronary arteries.

Intravascular imaging of angioplasty balloon under-expansion during pre-dilation predicts hyperelastic behavior of coronary artery lesions

“…The current results from a large sample size ( n = 13) relative prior work serve as a proof-of-concept for pre-operative patient-specific hyperelastic material characterization using a single commercially-available imaging approach (i.e., OCT) to capture hyperelastic behavior at physiologic and supra-physiologic deformations ( Guvenir Torun et al, 2021 ; Narayanan et al, 2021 ) applied during PCI. The current results extend the work of Narayanan et al who used inverse finite element methods to estimate the material properties of arterial plaque components ( Narayanan et al, 2021 ).…”

“…However, recent attempts for image-based characterization of plaque material properties have been limited to ex vivo approaches or multimodal intravascular imaging. Related work has also focused on physiological intravascular pressures ( Guvenir Torun et al, 2021 ; Narayanan et al, 2021 ), while nonlinearity of the plaque deformation (i.e., hyperelastic behavior) is best quantified beyond physiological deformations as applied during PCI. In this paper a novel approach is presented using OCT imaging through angioplasty balloons at pre-dilation to 8 ATM.…”

Inverse Finite Element Framework Combining Ultrasound Imaging and Inflation Testing of PVA Artery Phantoms

“…In the cases where the lipid was included (i.e., 25% and 50%), the recovered 𝐶 "/ values were respectively equal to 0.1 kPa and 0.38 kPa. The latter values are within the range of lipid pool material properties chosen in the literature for inverse FE modelling (Guvenir Torun et al, 2021). The final error 𝜖 defined in Section 2.a was minimized for n=1 sample of each stenosis percentage group i.e., 0%, 25%, 50% and 75%.…”

“…Akyildiz et al developed an iFEM method to determine local material properties of atherosclerotic plaques from ultrasound images used to create 2D finite element models (Akyildiz et al, 2016). Guvenir et al, went further into improving this ultrasound-based framework by introducing a Bayesian optimisation-based pipeline to refine the material property estimations from the iFEM (Guvenir Torun et al, 2021). In this study, we explore the pipeline presented by Narayanan et al, where an iFEM was used to obtain multiple patient specific parameters from optical coherence tomography (OCT) reconstructed atherosclerotic geometries based on an interface matching method (Narayanan et al, 2021).…”

Medical Image-Based Computational Fluid Dynamics and Fluid-Structure Interaction Analysis in Vascular Diseases

“…Biomechanical simulations using patient-specific anatomical and physiological data have been applied to study atherosclerosis in coronary ( Abbasian et al, 2020 ; Guvenir Torun et al, 2021 ), carotid ( Bennati et al, 2021 ), cerebral ( Tanoue et al, 2011 ), and femoral ( Wood et al, 2006 ) arteries; thoracic ( Boccadifuoco et al, 2018a ) and abdominal ( Taylor et al, 1998 ) aortas; aortic aneurysms ( Mariotti et al, 2021 ) and dissections ( Cheng et al, 2014 ); cerebral aneurysms ( Bazilevs et al, 2010 ); pulmonary arterial hypertension ( Zambrano et al, 2018 ); bypass grafts ( Sankaran et al, 2012 ), and arteriovenous fistulas for hemodialysis ( He et al, 2013 ). In addition to research, CFD simulations have also been used clinically to derive the coronary fractional flow reserve values in stenotic coronary arteries from CTA images, avoiding invasive coronary angiography ( Min et al, 2015 ).…”