Millions of people die worldwide each year due to cardiac complications caused by atherosclerosis.&nbsp;The term&nbsp;atherosclerosis&nbsp;is derived from the Greek "athero," meaning gruel, or wax, and "sclerosis" for hardening, or induration.&nbsp;Deposits made of fat, scar tissue and minerals accumulate at the arterial vessel; this deposit is called the atheroma. Once the atheroma gets large enough, it disturbs the normal hemodynamics and eventually breaks causing blood clots that lead to heart attacks or stroke.&nbsp;&nbsp;&nbsp;Atherosclerosis can still exhibit thrombosis leading to death without plaque rupture. Some studies show that 23-30% of patients demonstrated superficial plaque erosion as the primary cause of thrombosis. Superficial erosion occurs when vascular endothelial cells detach from the vessel wall thereby exposing collagen to the blood and activating the coagulation cascade. Currently there is no treatment for superficial erosion due in part to the fact that the mechanisms of how it forms are not well understood. Some studies suggest that a contributing factor for vessel erosion is disturbed flow caused by the atheroma occlusion.&nbsp;However, we believe that the process of vessel erosion is multifactorial in nature, with most contributing factors presently&nbsp;unkown.&nbsp;&nbsp;The aim of this study is to increase the understanding of how vessel erosion occurs.&nbsp;For this purpose, we will use virtual and in-vitro models that recreate the flow physics surrounding&nbsp;atheromas.&nbsp;Previously,&nbsp;we have conducted virtual simulations of a 3D carotid artery.&nbsp;Using Desing Modeler&nbsp;(Ansys Inc., Canonsburg, PA), a 3D&nbsp;virtual geometry of an artery with a hemispherical obstruction was created.&nbsp;Human-like dimensions were used, the vessel diameter being 3.1 mm, the length 30 mm and&nbsp;the obstruction itself centered 10 mm from the inlet, having a radius of 1.55 mm.&nbsp;This was followed by the construction of a standard mesh with 77,220 elements.&nbsp;Simulations were performed on&nbsp;CFX&nbsp;(Ansys Inc., Canonsburg, PA),&nbsp;selecting constants and methods that had previous validation from other studies.&nbsp;The applied conditions were laminar flow conditions with density = 1060 kg/m3&nbsp;and viscosity = 3.5 centipoise, as well as a&nbsp;zero relative&nbsp;pressure at the outlet, no-slip boundary condition at the vessel wall, and a time-dependent physiologically relevant velocity waveform&nbsp;at the inlet.&nbsp;This was all done on a Lenovo Desktop with&nbsp;Intel® Core™ i7-7500U CPU, 2.70 GHz (1 processor) with 16 Gb installed memory and 64-bit Windows 10 operating system.&nbsp;&nbsp;Using&nbsp;the 3D CAD software SOLIDWORKS,&nbsp;the chamber was designed in hopes of creating a functioning model of&nbsp;an atherosclerotic human artery.&nbsp;Using simplified characteristics, especially regarding the shape and size of the plaque buildup, the model was&nbsp;tailored to develop a basic, foundational understanding of the&nbsp;fluid-based mechanisms surrounding plaque in an artery.&nbsp;From the start of&nbsp;the project, it was decided that the artery itself would be split and connected through a screwing process. This would ensure that the inside components could be accessed with ease, while ensuring the overall structure was sound for&nbsp;testing purposes.&nbsp;Once decided, attention was then directed to implementation of the sample plaque, which needed to be sutured into the chamber without&nbsp;breaching the plaque itself. The solution&nbsp;that was selected involved lying the sample atop a&nbsp;thin plate that had suture holes available for attachment. To keep the plate and sample straight and&nbsp;stationary, a separate attachment was placed on the bottom surface in a location that would not interfere with the screwing&nbsp;mechanism.&nbsp;We hope to identify specific flow parameters that&nbsp;trigger the denudation of cells in atherosclerotic&nbsp;arteries.&nbsp;&nbsp;

A Study of Flow in Atherosclerotic Arteries Using Virtual and In-Vitro Models and Its Implications Regarding Vessel Erosion

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.