1
|
Alsabbagh Y, Erben Y, Vandenberg J, Farres H. New Trends of Personalized Medicine in the Management of Abdominal Aortic Aneurysm: A Review. J Pers Med 2024; 14:1148. [PMID: 39728062 DOI: 10.3390/jpm14121148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2024] [Revised: 11/30/2024] [Accepted: 12/06/2024] [Indexed: 12/28/2024] Open
Abstract
Abdominal aortic aneurysm (AAA) is a significant vascular condition characterized by the dilation of the abdominal aorta, presenting a substantial risk of rupture and associated high mortality rates. Current management strategies primarily rely on aneurysm diameter and growth rates to predict rupture risk and determine the timing of surgical intervention. However, this approach has limitations, as ruptures can occur in smaller AAAs below surgical thresholds, and many large AAAs remain stable without intervention. This review highlights the need for more precise and individualized assessment tools that integrate biomechanical parameters such as wall stress, wall strength, and hemodynamic factors. Advancements in imaging modalities like ultrasound elastography, computed tomography (CT) angiography, and magnetic resonance imaging (MRI), combined with artificial intelligence, offer enhanced capabilities to assess biomechanical indices and predict rupture risk more accurately. Incorporating these technologies can lead to personalized medicine approaches, improving decision-making regarding the timing of interventions. Additionally, emerging treatments focusing on targeted delivery of therapeutics to weakened areas of the aortic wall, such as nanoparticle-based drug delivery, stem cell therapy, and gene editing techniques like CRISPR-Cas9, show promise in strengthening the aortic wall and halting aneurysm progression. By validating advanced screening modalities and developing targeted treatments, the future management of AAA aims to reduce unnecessary surgeries, prevent ruptures, and significantly improve patient outcomes.
Collapse
Affiliation(s)
- Yaman Alsabbagh
- Division of Vascular and Endovascular Surgery, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Young Erben
- Division of Vascular and Endovascular Surgery, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Jonathan Vandenberg
- Division of Vascular and Endovascular Surgery, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Houssam Farres
- Division of Vascular and Endovascular Surgery, Mayo Clinic, Jacksonville, FL 32224, USA
| |
Collapse
|
2
|
S SN, Bhattacharjee A, Saha S. CFD analysis of the hyper-viscous effects on blood flow across abdominal aortic aneurysm in COVID patients: multiphysics approach. Comput Methods Biomech Biomed Engin 2024; 27:570-586. [PMID: 37021363 DOI: 10.1080/10255842.2023.2194474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/19/2023] [Indexed: 04/07/2023]
Abstract
Recent research has shown that individuals suffering from COVID-19 are accommodating an elevated level of blood viscosity due to the morphological changes in blood cells. As viscosity is a major flow parameter influencing the flow across a stenosis or an aneurysm, the examination of the significance of hyperviscosity in COVID patients is imperative in arterial pathologies. In this research, we have considered a patient-specific case in which the aneurysm is located along the abdominal aortal walls. Recent research on the side effects of COVID-19 voiced out the various effects on the circulatory system of humans. Also, as abdominal aneurysms exist very often among individuals, causing the death of 150-200 million every year, the hyper-viscous effects of blood on the flow across the diseased aorta are explored by considering the elevated viscosity levels. In vitro explorations contribute considerably to the clinical methods and treatments to be regarded. The objective of the present inquest is to research the flow field in aneurysmatic-COVID-affected patients considering the elastic nature of vessel walls, using the arbitrary Lagrangian-Eulerian approach. The study supports the various clinical findings that voiced the detrimental effects associated with blood hyperviscosity. The simulation results obtained, by solving the fluid mechanics' equations coupled with the solid mechanics' equations, employing a FEM solver suggest that the elevated stress imparted by the hyper-viscous flows on the walls of the aneurysmal aorta can trigger the fastening of the aneurysmal sac enlargement or rupture.
Collapse
Affiliation(s)
- Shankar Narayan S
- Department of Mathematics and Statistics, Ramaiah University of Applied Sciences, Bengaluru, India
- Department of Mathematics, Dayananda Sagar University, Bengaluru, India
| | | | - Sunanda Saha
- Department of Mathematics, Vellore Institute of Technology, Vellore, India
| |
Collapse
|
3
|
Amani A, Farajollahi AH. Drug Delivery Angle for Various Atherosclerosis and Aneurysm Percentages of the Carotid Artery. Mol Pharm 2024; 21:1777-1793. [PMID: 38478900 DOI: 10.1021/acs.molpharmaceut.3c01109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Stroke is the second cause of mortality among adult males and the first cause of death in adult females all around the world. It is also recognized as one of the most important causes of morbidity and dementia in adults. Stenosis or rupture of the only channels of the blood supply from the heart to the brain (carotid arteries) is among the main causes of stroke. In this regard, treatment of the lesions of carotid arteries, including atherosclerosis and aneurysm, could be a huge step in preventing stroke and improving brain performance. Targeted drug delivery by drug-carrying nanoparticles is the latest method for optimal delivery of drug to the damaged parts of the artery. In this study, a wide range of carotid artery lesions, including different percentages of atherosclerosis and aneurysm, were considered. After analyzing the dynamics of the fluid flow in different damaged regions and selecting the magnetic framework with proper ligand (Fe3O4@MOF) as the drug carrier, the size of the particles and their number per cycle were analyzed. Based on the results, the particle size of 100 nm and the use of 300 particles per injection at each cardiac cycle can result in maximum drug delivery to the target site. Then, the effect of the hospital bed angle on drug delivery was investigated. The results showed a unique optimal drug delivery angle for each extent of atherosclerosis or aneurysm. For example, in a 50% aneurysm, drug delivery at an angle of 30° is about 387% higher than that at an angle of 15°. Finally, simulation of real geometry indicated the effectiveness of simple geometry instead of real geometry for the simulation of carotid arteries, which can remarkably decrease the computational time and costs.
Collapse
Affiliation(s)
- Ali Amani
- School of Mechanical Engineering, Sharif University of Technology, Tehran 11155-9466, Iran
| | | |
Collapse
|
4
|
Han HC, Sultan S, Xiang M. The effects of axial twisting and material non-symmetry on arterial bent buckling. J Biomech 2023; 157:111735. [PMID: 37499429 DOI: 10.1016/j.jbiomech.2023.111735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/25/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023]
Abstract
Artery buckling occurs due to hypertensive lumen pressure or reduced axial tension and other pathological conditions. Since arteries in vivo often experience axial twisting and the collagen fiber alignment in the arterial wall may become nonsymmetric, it is imperative to know how axial twisting and nonsymmetric collagen alignment would affect the buckling behavior of arteries. To this end, the objective of this study was to determine the effect of axial twisting and nonsymmetric collagen fiber distribution on the critical pressure of arterial bent buckling. The buckling model analysis was generalized to incorporate an axial twist angle and nonsymmetric fiber alignment. The effect of axial twisting on the critical pressure was simulated and experimentally tested in a group of porcine carotid arteries. Our results showed that axial twisting tends to reduce the critical pressure depending on the axial stretch ratio and twist angle. In addition, nonsymmetric fiber alignment reduces the critical pressure. Experimental results confirmed that a twist angle of 90° reduces the critical pressure significantly (p < 0.05). It was concluded that axial twisting and non-axisymmetric collagen fibers distribution could make arteries prone to bent buckling. These results enrich our understanding of artery buckling and vessel tortuosity. The model analysis and results could also be applicable to other fiber reinforced tubes under lumen pressure and axial twisting.
Collapse
Affiliation(s)
- Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, United States.
| | - Sarah Sultan
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, United States
| | - Michael Xiang
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, United States
| |
Collapse
|
5
|
Syed F, Khan S, Toma M. Modeling Dynamics of the Cardiovascular System Using Fluid-Structure Interaction Methods. BIOLOGY 2023; 12:1026. [PMID: 37508455 PMCID: PMC10376821 DOI: 10.3390/biology12071026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/07/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Using fluid-structure interaction algorithms to simulate the human circulatory system is an innovative approach that can provide valuable insights into cardiovascular dynamics. Fluid-structure interaction algorithms enable us to couple simulations of blood flow and mechanical responses of the blood vessels while taking into account interactions between fluid dynamics and structural behaviors of vessel walls, heart walls, or valves. In the context of the human circulatory system, these algorithms offer a more comprehensive representation by considering the complex interplay between blood flow and the elasticity of blood vessels. Algorithms that simulate fluid flow dynamics and the resulting forces exerted on vessel walls can capture phenomena such as wall deformation, arterial compliance, and the propagation of pressure waves throughout the cardiovascular system. These models enhance the understanding of vasculature properties in human anatomy. The utilization of fluid-structure interaction methods in combination with medical imaging can generate patient-specific models for individual patients to facilitate the process of devising treatment plans. This review evaluates current applications and implications of fluid-structure interaction algorithms with respect to the vasculature, while considering their potential role as a guidance tool for intervention procedures.
Collapse
Affiliation(s)
- Faiz Syed
- College of Osteopathic Medicine, New York Institute of Technology, Northern Boulevard, Old Westbury, NY 11568, USA
| | - Sahar Khan
- College of Osteopathic Medicine, New York Institute of Technology, Northern Boulevard, Old Westbury, NY 11568, USA
| | - Milan Toma
- College of Osteopathic Medicine, New York Institute of Technology, Northern Boulevard, Old Westbury, NY 11568, USA
| |
Collapse
|
6
|
Silva MLFDA, Gonçalves SDEF, Haniel J, Lucas TC, Huebner R. Comparative study between 1-way and 2-way coupled fluid-structure interaction in numerical simulation of aortic arch aneurysms. AN ACAD BRAS CIENC 2023; 95:e20210859. [PMID: 37255166 DOI: 10.1590/0001-3765202320210859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/19/2022] [Indexed: 06/01/2023] Open
Abstract
Hemodynamic forces are related to pathological variations of the cardiovascular system, and numerical simulations for fluid-structure interaction have been systematically used to analyze the behavior of blood flow and the arterial wall in aortic aneurysms. This paper proposes a comparative analysis of 1-way and 2-way coupled fluid-structure interaction for aortic arch aneurysm. The coupling models of fluid-structure interaction were conducted using 3D geometry of the thoracic aorta from computed tomography. Hyperelastic anisotropic properties were estimated for the Holzapfel arterial wall model. The rheological behavior of the blood was modeled by the Carreau-Yasuda model. The results showed that the 1-way approach tends to underestimate von Mises stress, displacement, and strain over the entire cardiac cycle, compared to the 2-way approach. In contrast, the behavior of the variables of flow field, velocity, wall shear stress, and Reynolds number when coupled by the 1-way model was overestimated at the systolic moment and tends to be equal at the diastolic moment. The quantitative differences found, especially during the systole, suggest the use of 2-way coupling in numerical simulations of aortic arch aneurysms due to the hyperelastic nature of the arterial wall, which leads to a strong iteration between the fluid and the arterial wall.
Collapse
Affiliation(s)
- Mário Luis F DA Silva
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Saulo DE Freitas Gonçalves
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Jonathas Haniel
- Programa de Pós-Graduação em Engenharia Mecânica, Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| | - Thabata C Lucas
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Departamento de Enfermagem, MGC 367, km 583, 5000, Alto da Jacuba, 39100-000 Diamantina, MG, Brazil
| | - Rudolf Huebner
- Universidade Federal de Minas Gerais, Departamento de Engenharia Mecânica, Avenida Presidente Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil
| |
Collapse
|
7
|
Chandrashekar A, Handa A, Lapolla P, Shivakumar N, Ngetich E, Grau V, Lee R. Prediction of Abdominal Aortic Aneurysm Growth Using Geometric Assessment of Computerized Tomography Images Acquired During the Aneurysm Surveillance Period. Ann Surg 2023; 277:e175-e183. [PMID: 33630463 PMCID: PMC8691375 DOI: 10.1097/sla.0000000000004711] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We investigated the utility of geometric features for future AAA growth prediction. BACKGROUND Novel methods for growth prediction of AAA are recognized as a research priority. Geometric feature have been used to predict cerebral aneurysm rupture, but not examined as predictor of AAA growth. METHODS Computerized tomography (CT) scans from patients with infra-renal AAAs were analyzed. Aortic volumes were segmented using an automated pipeline to extract AAA diameter (APD), undulation index (UI), and radius of curvature (RC). Using a prospectively recruited cohort, we first examined the relation between these geometric measurements to patients' demographic features (n = 102). A separate 192 AAA patients with serial CT scans during AAA surveillance were identified from an ongoing clinical database. Multinomial logistic and multiple linear regression models were trained and optimized to predict future AAA growth in these patients. RESULTS There was no correlation between the geometric measurements and patients' demographic features. APD (Spearman r = 0.25, P < 0.05), UI (Spearman r = 0.38, P < 0.001) and RC (Spearman r =-0.53, P < 0.001) significantly correlated with annual AAA growth. Using APD, UI, and RC as 3 input variables, the area under receiver operating characteristics curve for predicting slow growth (<2.5 mm/yr) or fast growth (>5 mm/yr) at 12 months are 0.80 and 0.79, respectively. The prediction or growth rate is within 2 mm error in 87% of cases. CONCLUSIONS Geometric features of an AAA can predict its future growth. This method can be applied to routine clinical CT scans acquired from patients during their AAA surveillance pathway.
Collapse
Affiliation(s)
- Anirudh Chandrashekar
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
- Department of Engineering Science, University, of Oxford, Oxford, United Kingdom
| | - Ashok Handa
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Pierfrancesco Lapolla
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Natesh Shivakumar
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Elisha Ngetich
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Vicente Grau
- Department of Engineering Science, University, of Oxford, Oxford, United Kingdom
| | - Regent Lee
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
8
|
Flores Gerónimo J, Keramat A, Alastruey J, Duan HF. Computational modelling and application of mechanical waves to detect arterial network anomalies: Diagnosis of common carotid stenosis. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2022; 227:107213. [PMID: 36356386 DOI: 10.1016/j.cmpb.2022.107213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE This paper proposes a novel strategy to localize anomalies in the arterial network based on its response to controlled transient waves. The idea is borrowed from system identification theories in which wave reflections can render significant information about a target system. Cardiovascular system studies often focus on the waves originating from the heart pulsations, which are of low bandwidth and, hence, can hardly carry information about the arteries with the desired resolution. METHODS Our strategy uses a relatively higher bandwidth transient signal to characterize healthy and unhealthy arterial networks through a frequency response function (FRF). We tested our novel approach on data simulated using a one-dimensional cardiovascular model that produced pulse waves in the larger arteries of the arterial network. Specifically, we excited the blood flow from the brachial artery with a relatively high bandwidth flow disturbance and collected the subsequent pressure waveform at peripheral positions. To better differentiate FRFs of healthy and unhealthy networks, we used a FRF that removes the effects of heart pulsations. RESULTS Results demonstrate the ability of the proposed FRF to detect and follow-up on the development of a common carotid artery (CCA) stenosis. We tested distinct geometrical variations of the stenosis (size, length and position) and observed differences between the FRFs of healthy and unhealthy networks in all cases; such differences were mainly due to geometrical variations determined by the stenosis. CONCLUSIONS We have provided a theoretical proof of concept that demonstrates the ability of our novel strategy to detect and track the development of CCA stenosis by using peripheral pressure waves that can be measured non-invasively in clinical practice.
Collapse
Affiliation(s)
- Joaquín Flores Gerónimo
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Alireza Keramat
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
| | - Jordi Alastruey
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Huan-Feng Duan
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| |
Collapse
|
9
|
Hejazi M, Phani AS. On growth, buckling, and rupture of aneurysms in cylindrical tubes. J Biomech 2022; 144:111313. [DOI: 10.1016/j.jbiomech.2022.111313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 07/20/2022] [Accepted: 09/18/2022] [Indexed: 11/29/2022]
|
10
|
Throop A, Bukac M, Zakerzadeh R. Prediction of wall stress and oxygen flow in patient-specific abdominal aortic aneurysms: the role of intraluminal thrombus. Biomech Model Mechanobiol 2022; 21:1761-1779. [PMID: 35908098 DOI: 10.1007/s10237-022-01618-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/13/2022] [Indexed: 11/28/2022]
Abstract
In this study, the biomechanical role of intraluminal thrombus (ILT) in an abdominal aortic aneurysm (AAA) is investigated. The implications of ILT in AAA are controversial in literature. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing wall stress, whereas other studies have associated ILT with inhibiting oxygen transport and inducing aortic wall weakening. Therefore, we sought to explore the connection between ILT, mechanical stresses, and oxygen flow in different geometries of patient-specific aneurysms with varying ILT morphologies. The objective is to investigate the extent to which ILT influences the prediction of aneurysmal wall stresses that are associated with rupture, as well as oxygen concentrations to measure tissue oxygen deprivation. Three patient-specific AAA geometries are considered, and two models, one with ILT and one without ILT, are created for each patient to assess the effect of ILT presence. A fluid-structure interaction approach is used to couple the blood flow, wall deformation, and oxygen mass transport. Results are presented for hemodynamics patterns, wall stress measures, and oxygen metrics within the arterial wall. While ILT is found to reduce wall stress, simulations confirm that ILT decreases oxygen transport within the tissue significantly, leading to wall hypoxia.
Collapse
Affiliation(s)
- Alexis Throop
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, 413 Libermann Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA
| | - Martina Bukac
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN, USA
| | - Rana Zakerzadeh
- Department of Engineering, Rangos School of Health Sciences, Duquesne University, 413 Libermann Hall, 600 Forbes Avenue, Pittsburgh, PA, 15282, USA.
| |
Collapse
|
11
|
Study of Non-Newtonian biomagnetic blood flow in a stenosed bifurcated artery having elastic walls. Sci Rep 2021; 11:23835. [PMID: 34903853 PMCID: PMC8669029 DOI: 10.1038/s41598-021-03426-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/29/2021] [Indexed: 11/19/2022] Open
Abstract
Fluid structure interaction (FSI) gained attention of researchers and scientist due to its applications in science fields like biomedical engineering, mechanical engineering etc. One of the major application in FSI is to study elastic wall behavior of stenotic arteries. In this paper we discussed an incompressible Non-Newtonian blood flow analysis in an elastic bifurcated artery. A magnetic field is applied along \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$x$$\end{document}x direction. For coupling of the problem an Arbitrary Lagrangian–Eulerian formulation is used by two-way fluid structure interaction. To discretize the problem, we employed \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$P_{2} P_{1}$$\end{document}P2P1 finite element technique to approximate the velocity, displacement and pressure and then linearized system of equations is solved using Newton iteration method. Analysis is carried out for power law index, Reynolds number and Hartmann number. Hemodynamic effects on elastic walls, stenotic artery and bifurcated region are evaluated by using velocity profile, pressure and loads on the walls. Study shows there is significant increase in wall shear stresses with an increase in Power law index and Hartmann number. While as expected increase in Reynolds number decreases the wall shear stresses. Also load on the upper wall is calculated against Hartmann number for different values of power law index. Results show load increases as the Hartmann number and power law index increases. From hemodynamic point of view, the load on the walls is minimum for shear thinning case but when power law index increased i.e. for shear thickening case load on the walls increased.
Collapse
|
12
|
Tripathi J, Vasu B, Bég OA, Gorla RSR, Kameswaran PK. Computational simulation of rheological blood flow containing hybrid nanoparticles in an inclined catheterized artery with stenotic, aneurysmal and slip effects. Comput Biol Med 2021; 139:105009. [PMID: 34775156 DOI: 10.1016/j.compbiomed.2021.105009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/15/2022]
Abstract
Influenced by nano-drug delivery applications, the present article considers the collective effects of hybrid biocompatible metallic nanoparticles (Silver and Copper), a stenosis and an aneurysm on the unsteady blood flow characteristics in a catheterized tapered inclined artery. The non-Newtonian Carreau fluid model is deployed to represent the hemorheological characteristics in the arterial region. A modified Tiwari-Das volume fraction model is adopted for nanoscale effects. The permeability of the arterial wall and the inclination of the diseased artery are taken into account. The nanoparticles are also considered to have various shapes (bricks, cylinders, platelets, blades) and therefore the influence of different shape parameters is discussed. The conservation equations for mass, linear momentum and energy are normalized by employing suitable non-dimensional variables. The transformed equations with associated boundary conditions are solved numerically using the FTCS method. Key hemodynamic characteristics i.e. velocity, temperature, flow rate, wall shear stress (WSS) in stenotic and aneurysm region for a particular critical height of the stenosis, are computed. Hybrid nanoparticles (Ag-Cu/Blood) accelerate the axial flow and increase temperatures significantly compared with unitary nanoparticles (Ag/blood), at both the stenosis and aneurysm segments. Axial velocity, temperature and flow rate are all enhanced with greater nanoparticle shape factor. Axial velocity, temperature, wall shear stress and flow rate magnitudes are always comparatively higher at the aneurysm region compared with the stenotic segment. The simulations provide novel insights into the performance of different nanoparticle geometries and also rheological behaviour in realistic nano-pharmaco-dynamic transport and percutaneous coronary intervention (PCI).
Collapse
Affiliation(s)
- Jayati Tripathi
- Department of Mathematics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, U.P, India
| | - B Vasu
- Department of Mathematics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, U.P, India.
| | - O Anwar Bég
- Department of Mechanical and Aeronautical Engineering, Salford University, Salford, M54WT, UK
| | - Rama Subba Reddy Gorla
- Department of Aeronautics and Astronautics, Air Force Institute of Technology, Wright Patterson Air Force Base, Dayton, OH, 45433, USA
| | - Peri K Kameswaran
- Department of Mathematics, School of Advanced Sciences, VIT University, Vellore, 632014, India
| |
Collapse
|
13
|
Ghorbanniahassankiadeh A, Marks DS, LaDisa JF. Correlation of Computational Instantaneous Wave-Free Ratio With Fractional Flow Reserve for Intermediate Multivessel Coronary Disease. J Biomech Eng 2021; 143:051011. [PMID: 33454732 DOI: 10.1115/1.4049746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Indexed: 01/14/2023]
Abstract
This study computationally assesses the accuracy of an instantaneous wave-free ratio (iFR) threshold range compared to standard modalities such as fractional flow reserve (FFR) and coronary flow reserve (CFR) for multiple intermediate lesions near the left main (LM) coronary bifurcation. iFR is an adenosine-independent index encouraged for assessment of coronary artery disease (CAD), but different thresholds are debated. This becomes particularly challenging in cases of multivessel disease when sensitivity to downstream lesions is unclear. Idealized LM coronary arteries with 34 different intermediate stenoses were created and categorized (Medina) as single and multiple lesion groups. Computational fluid dynamics modeling was performed with physiologic boundary conditions using an open-source software (simvascular1) to solve the time-dependent Navier-Stokes equations. A strong linear relationship between iFR and FFR was observed among studied models, indicating computational iFR values of 0.92 and 0.93 are statistically equivalent to an FFR of 0.80 in single and multiple lesion groups, respectively. At the clinical FFR value (i.e., 0.8), a triple-lesion group had smaller CFR compared to the single and double lesion groups (e.g., triple = 3.077 versus single = 3.133 and double = 3.132). In general, the effect of additional intermediate downstream lesions (minimum lumen area > 3 mm2) was not statistically significant for iFR and CFR. A computational iFR of 0.92 best predicts an FFR of 0.80 and may be recommended as threshold criteria for computational assessment of LM stenosis following additional validation using patient-specific models.
Collapse
Affiliation(s)
- Arash Ghorbanniahassankiadeh
- Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, 8701 W Watertown Plank Road, Milwaukee, WI 53226
| | - David S Marks
- Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226
| | - John F LaDisa
- Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, 8701 W Watertown Plank Road, Milwaukee, WI 53226; Department of Physiology, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226; Department of Medicine, Medical College of Wisconsin, 8701 W Watertown Plank Road, Milwaukee, WI 53226
| |
Collapse
|
14
|
Wang Y, Lee WN. Non-Invasive Estimation of Localized Dynamic Luminal Pressure Change by Ultrasound Elastography in Arteries With Normal and Abnormal Geometries. IEEE Trans Biomed Eng 2021; 68:1627-1637. [DOI: 10.1109/tbme.2020.3028186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Jin W, Alastruey J. Arterial pulse wave propagation across stenoses and aneurysms: assessment of one-dimensional simulations against three-dimensional simulations and in vitro measurements. J R Soc Interface 2021; 18:20200881. [PMID: 33849337 PMCID: PMC8086929 DOI: 10.1098/rsif.2020.0881] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
One-dimensional (1-D) arterial blood flow modelling was tested in a series of idealized vascular geometries representing the abdominal aorta, common carotid and iliac arteries with different sizes of stenoses and/or aneurysms. Three-dimensional (3-D) modelling and in vitro measurements were used as ground truth to assess the accuracy of 1-D model pressure and flow waves. The 1-D and 3-D formulations shared identical boundary conditions and had equivalent vascular geometries and material properties. The parameters of an experimental set-up of the abdominal aorta for different aneurysm sizes were matched in corresponding 1-D models. Results show the ability of 1-D modelling to capture the main features of pressure and flow waves, pressure drop across the stenoses and energy dissipation across aneurysms observed in the 3-D and experimental models. Under physiological Reynolds numbers (Re), root mean square errors were smaller than 5.4% for pressure and 7.3% for the flow, for stenosis and aneurysm sizes of up to 85% and 400%, respectively. Relative errors increased with the increasing stenosis and aneurysm size, aneurysm length and Re, and decreasing stenosis length. All data generated in this study are freely available and provide a valuable resource for future research.
Collapse
Affiliation(s)
- Weiwei Jin
- Department of Biomedical Engineering, King's College London, London, UK
| | - Jordi Alastruey
- Department of Biomedical Engineering, King's College London, London, UK.,World-Class Research Center 'Digital Biodesign and Personalized Healthcare', Sechenov University, Moscow, Russia
| |
Collapse
|
16
|
Sharzehee M, Seddighi Y, Sprague EA, Finol EA, Han HC. A Hemodynamic Comparison of Myocardial Bridging and Coronary Atherosclerotic Stenosis: A Computational Model With Experimental Evaluation. J Biomech Eng 2021; 143:031013. [PMID: 33269788 DOI: 10.1115/1.4049221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Indexed: 11/08/2022]
Abstract
Myocardial bridging (MB) and coronary atherosclerotic stenosis can impair coronary blood flow and may cause myocardial ischemia or even heart attack. It remains unclear how MB and stenosis are similar or different regarding their impacts on coronary hemodynamics. The purpose of this study was to compare the hemodynamic effects of coronary stenosis and MB using experimental and computational fluid dynamics (CFD) approaches. For CFD modeling, three MB patients with different levels of lumen obstruction, mild, moderate, and severe were selected. Patient-specific left anterior descending (LAD) coronary artery models were reconstructed from biplane angiograms. For each MB patient, the virtually healthy and stenotic models were also simulated for comparison. In addition, an in vitro flow-loop was developed, and the pressure drop was measured for comparison. The CFD simulations results demonstrated that the difference between MB and stenosis increased with increasing MB/stenosis severity and flowrate. Experimental results showed that increasing the MB length (by 140%) only had significant impact on the pressure drop in the severe MB (39% increase at the exercise), but increasing the stenosis length dramatically increased the pressure drop in both moderate and severe stenoses at all flow rates (31% and 93% increase at the exercise, respectively). Both CFD and experimental results confirmed that the MB had a higher maximum and a lower mean pressure drop in comparison with the stenosis, regardless of the degree of lumen obstruction. A better understanding of MB and atherosclerotic stenosis may improve the therapeutic strategies in coronary disease patients and prevent acute coronary syndromes.
Collapse
Affiliation(s)
- Mohammadali Sharzehee
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249
| | - Yasamin Seddighi
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249
| | - Eugene A Sprague
- Department of Medicine, University of Texas Health San Antonio, San Antonio, TX 78229
| | - Ender A Finol
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249
| | - Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249
| |
Collapse
|
17
|
Biomass gasification in a downdraft fixed-bed gasifier: Optimization of operating conditions. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116249] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
18
|
Biomechanical Force Prediction for Lengthening of Small Intestine during Distraction Enterogenesis. Bioengineering (Basel) 2020; 7:bioengineering7040140. [PMID: 33171760 PMCID: PMC7711478 DOI: 10.3390/bioengineering7040140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/04/2020] [Accepted: 10/28/2020] [Indexed: 11/16/2022] Open
Abstract
Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common form of intestinal failure. Different strategies including parenteral nutrition and surgical lengthening to manage patients with short bowel syndrome are associated with high complication rates. More recently, self-expanding springs have been used to lengthen the small intestine using an intraluminal axial mechanical force, where this biomechanical force stimulates the growth and elongation of the small intestine. Differences in physical characteristics of patients with short bowel syndrome would require a different mechanical force—this is crucial in order to achieve an efficient and safe lengthening outcome. In this study, we aimed to predict the required mechanical force for each potential intestinal size. Based on our previous experimental observations and computational findings, we integrated our experimental measurements of patient biometrics along with mechanical characterization of the soft tissue into our numerical simulations to develop a series of computational models. These computational models can predict the required mechanical force for any potential patient where this can be advantageous in predicting an individual’s tissue response to spring-mediated distraction enterogenesis and can be used toward a safe delivery of the mechanical force.
Collapse
|
19
|
Hirschhorn M, Tchantchaleishvili V, Stevens R, Rossano J, Throckmorton A. Fluid–structure interaction modeling in cardiovascular medicine – A systematic review 2017–2019. Med Eng Phys 2020; 78:1-13. [DOI: 10.1016/j.medengphy.2020.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 01/18/2020] [Accepted: 01/26/2020] [Indexed: 01/06/2023]
|
20
|
Hosseini HS, Taylor JS, Wood LS, Dunn JC. Biomechanics of small intestine during distraction enterogenesis with an intraluminal spring. J Mech Behav Biomed Mater 2020; 101:103413. [DOI: 10.1016/j.jmbbm.2019.103413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 06/13/2019] [Accepted: 08/31/2019] [Indexed: 12/25/2022]
|
21
|
Sharzehee M, Fatemifar F, Han HC. Computational simulations of the helical buckling behavior of blood vessels. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3277. [PMID: 31680465 PMCID: PMC7286361 DOI: 10.1002/cnm.3277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 08/27/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Tortuous vessels are often observed in vivo and could hinder or even disrupt blood flow to distal organs. Besides genetic and biological factors, the in vivo mechanical loading seems to play a role in the formation of tortuous vessels, but the mechanism for formation of helical vessel shape remains unclear. Accordingly, the aim of this study was to investigate the biomechanical loads that trigger the occurrence of helical buckling in blood vessels using finite element analysis. Porcine carotid arteries were modeled as thick-walled cylindrical tubes using generalized Fung and Holzapfel-Gasser-Ogden constitutive models. Physiological loadings, including axial tension, lumen pressure, and axial torque, were applied. Simulations of various geometric dimensions, different constitutive models and at various levels of axial stretch ratios, lumen pressures, and twist angles were performed to identify the mechanical factors that determine the helical stability. Our results demonstrated that axial torsion can cause wringing (twist buckling) that leads to kinking or helical coiling and even looping and winding. The specific buckling patterns depend on the combination of lumen pressure, axial torque, axial tension, and the dimensions of the vessels. This study elucidates the mechanism of how blood vessels buckle under various mechanical loads and how complex mechanical loads yield helical buckling.
Collapse
Affiliation(s)
- Mohammadali Sharzehee
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Fatemeh Fatemifar
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX, USA
- Biomedical Engineering Program, UTSA-UTHSCSA, San Antonio, TX
| |
Collapse
|
22
|
Sharzehee M, Chang Y, Song JP, Han HC. Hemodynamic effects of myocardial bridging in patients with hypertrophic cardiomyopathy. Am J Physiol Heart Circ Physiol 2019; 317:H1282-H1291. [PMID: 31674812 DOI: 10.1152/ajpheart.00466.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Myocardial bridging (MB) is linked to angina and myocardial ischemia and may lead to sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, it remains unclear how MB affect the coronary blood flow in HCM patients. The aim of this study was to assess the effects of MB on coronary hemodynamics in HCM patients. Fifteen patients with MB (7 HCM and 8 non-HCM controls) in their left anterior descending (LAD) coronary artery were chosen. Transient computational fluid dynamics (CFD) simulations were conducted in anatomically realistic models of diseased (with MB) and virtually healthy (without MB) LAD from these patients, reconstructed from biplane angiograms. Our CFD simulation results demonstrated that dynamic compression of MB led to diastolic flow disturbances and could significantly reduce the coronary flow in HCM patients as compared with non-HCM group (P < 0.01). The pressure drop coefficient was remarkably higher (P < 0.05) in HCM patients. The flow rate change is strongly correlated with both upstream Reynolds number and MB compression ratio, while the MB length has less impact on coronary flow. The hemodynamic results and clinical outcomes revealed that HCM patients with an MB compression ratio higher than 65% required a surgical intervention. In conclusion, the transient MB compression can significantly alter the diastolic flow pattern and wall shear stress distribution in HCM patients. HCM patients with severe MB may need a surgical intervention.NEW & NOTEWORTHY In this study, the hemodynamic significance of myocardial bridging (MB) in patients with hypertrophic cardiomyopathy (HCM) was investigated to provide valuable information for surgical decision-making. Our results illustrated that the transient MB compression led to complex flow patterns, which can significantly alter the diastolic flow and wall shear stress distribution. The hemodynamic results and clinical outcomes demonstrated that patients with HCM and an MB compression ratio higher than 65% required a surgical intervention.
Collapse
Affiliation(s)
- Mohammadali Sharzehee
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, Texas
| | - Yuan Chang
- Department of Cardiac Surgery, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing, China
| | - Jiang-Ping Song
- Department of Cardiac Surgery, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Beijing, China
| | - Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, Texas
| |
Collapse
|
23
|
Azar D, Torres WM, Davis LA, Shaw T, Eberth JF, Kolachalama VB, Lessner SM, Shazly T. Geometric determinants of local hemodynamics in severe carotid artery stenosis. Comput Biol Med 2019; 114:103436. [PMID: 31521900 DOI: 10.1016/j.compbiomed.2019.103436] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 01/30/2023]
Abstract
In cases of severe carotid artery stenosis (CAS), carotid endarterectomy (CEA) is performed to recover lumen patency and alleviate stroke risk. Under current guidelines, the decision to surgically intervene relies primarily on the percent loss of native arterial lumen diameter within the stenotic region (i.e. the degree of stenosis). An underlying premise is that the degree of stenosis modulates flow-induced wall shear stress elevations at the lesion site, and thus indicates plaque rupture potential and stroke risk. Here, we conduct a retrospective study on pre-CEA computed tomography angiography (CTA) images from 50 patients with severe internal CAS (>60% stenosis) to better understand the influence of plaque and local vessel geometry on local hemodynamics, with geometrical descriptors that extend beyond the degree of stenosis. We first processed CTA images to define a set of multipoint geometric metrics characterizing the stenosed region, and next performed computational fluid dynamics simulations to quantify local wall shear stress and associated hemodynamic metrics. Correlation and regression analyses were used to relate obtained geometric and hemodynamic metrics, with inclusion of patient sub-classification based on the degree of stenosis. Our results suggest that in the context of severe CAS, prediction of shear stress-based metrics can be enhanced by consideration of readily available, multipoint geometric metrics in addition to the degree of stenosis.
Collapse
Affiliation(s)
- Dara Azar
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA
| | - William M Torres
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA; Exponent, Inc, Philadelphia, PA, USA
| | - Lindsey A Davis
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA; Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Taylor Shaw
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - John F Eberth
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA; Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Vijaya B Kolachalama
- Section of Computational Biomedicine, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Susan M Lessner
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA; Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Tarek Shazly
- Biomedical Engineering Program, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA; Department of Mechanical Engineering, College of Engineering and Computing, University of South Carolina, Columbia, SC, USA.
| |
Collapse
|
24
|
Peng L, Qiu Y, Yang Z, Yuan D, Dai C, Li D, Jiang Y, Zheng T. Patient-specific Computational Hemodynamic Analysis for Interrupted Aortic Arch in an Adult: Implications for Aortic Dissection Initiation. Sci Rep 2019; 9:8600. [PMID: 31197221 PMCID: PMC6565632 DOI: 10.1038/s41598-019-45097-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/30/2019] [Indexed: 02/08/2023] Open
Abstract
The guideline for the treatment of interrupted aortic arch (IAA) in adults has not been established although most centers tend to propose surgery. There is no clear evidence for the preferred selection of surgical repair versus conservatively medical treatment for the uncertain effects of both treatments. However, reports of sporadic aortic dissection (AD) of descending aorta (DAo) in IAA in adults before surgery drew our attention. It is quite perplexing because there seems to be no risk factors for the development of AD at DAo such as long-term uncontrolled hypertension, atherosclerosis, aortic aneurysm or genetic disorder. In this paper, we carried out the numerical investigation on the hemodynamics in a patient-specific IAA model, which was reconstructed from computed tomography images. Hemodynamic parameters including the flow pattern, pressure distribution, and wall shear stress (WSS) indicators were obtained. The simulation revealed that the jet flows from the collateral arteries (CAs) induced risk hemodynamic forces on the lumen wall including high time-averaged wall shear stress (TAWSS), high pressure and rapid change of WSS direction throughout the cardiac cycle. Moreover, it is found that only a jet flow which circumferentially washes out the aortic wall might cause tears on the wall. It is concluded that the specific geometrical features of the extensive major CAs might result in the risky hemodynamics leading to the initiation and development of AD in this particular IAA patient. CFD analysis in IAA can provide a clinical reference, and the results should be further studied in depth in the future.
Collapse
Affiliation(s)
- Liqing Peng
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yue Qiu
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Zhigang Yang
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ding Yuan
- Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Chenzhong Dai
- Department of Radiology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Da Li
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Yi Jiang
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China
| | - Tinghui Zheng
- Department of Applied Mechanics, Sichuan University, Chengdu, 610065, China.
| |
Collapse
|
25
|
Abstract
The Abdominal Aortic Aneurysm (AAA) is a local dilation of the abdominal aorta and it is a cause for serious concern because of the high mortality associated with its rupture. Consequently, the understanding of the phenomena related to the creation and the progression of an AAA is of crucial importance. In this work, the complicated interaction between the blood flow and the AAA wall is numerically examined using a fully coupled Fluid-Structure Interaction (FSI) method. The study investigates the possible link between the dynamic behavior of an AAA and the blood viscosity variations attributed to the haematocrit value, while it also incorporates the pulsatile blood flow, the non-Newtonian behavior of blood and the hyperelasticity of the arterial wall. It was found that blood viscosity has no significant effect on von Mises stress magnitude and distribution, whereas there is a close relation between the haematocrit value and the Wall Shear Stress (WSS) magnitude in AAAs. This WSS variation can possibly alter the mechanical properties of the arterial wall and increase its growth rate or even its rupture possibility. The relationship between haematocrit and dynamic behavior of an AAA can be helpful in designing a patient specific treatment.
Collapse
|
26
|
Zhu Y, Chen R, Juan YH, Li H, Wang J, Yu Z, Liu H. Clinical validation and assessment of aortic hemodynamics using computational fluid dynamics simulations from computed tomography angiography. Biomed Eng Online 2018; 17:53. [PMID: 29720173 PMCID: PMC5932836 DOI: 10.1186/s12938-018-0485-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 04/23/2018] [Indexed: 02/02/2023] Open
Abstract
Background Hemodynamic information including peak systolic pressure (PSP) and peak systolic velocity (PSV) carry an important role in evaluation and diagnosis of congenital heart disease (CHD). Since MDCTA cannot evaluate hemodynamic information directly, the aim of this study is to provide a noninvasive method based on a computational fluid dynamics (CFD) model, derived from multi-detector computed tomography angiography (MDCTA) raw data, to analyze the aortic hemodynamics in infants with CHD, and validate these results against echocardiography and cardiac catheter measurements. Methods This study included 25 patients (17 males, and 8 females; a median age of 2 years, range: 4 months–4 years) with CHD. All patients underwent both transthoracic echocardiography (TTE) and MDCTA within 2 weeks prior to cardiac catheterization. CFD models were created from MDCTA raw data. Boundary conditions were confirmed by lumped parameter model and transthoracic echocardiography (TTE). Peak systolic velocity derived from CFD models (PSVCFD) was compared to TTE measurements (PSVTTE), while the peak systolic pressure derived from CFD (PSPCFD) was compared to catheterization (PSPCC). Regions with low and high peak systolic wall shear stress (PSWSS) were also evaluated. Results PSVCFD and PSPCFD showed good agreements between PSVTTE (r = 0.968, p < 0.001; mean bias = − 7.68 cm/s) and PSPCC (r = 0.918, p < 0.001; mean bias = 1.405 mmHg). Regions with low and high PSWSS) can also be visualized. Skewing of velocity or helical blood flow was also observed at aortic arch in patients. Conclusions Our result demonstrated that CFD scheme based on MDCTA raw data is an accurate and convenient method in obtaining the velocity and pressure from aorta and displaying the distribution of PSWSS and flow pattern of aorta. The preliminary results from our study demonstrate the capability in combining clinical imaging data and novel CFD tools in infants with CHD and provide a noninvasive approach for diagnose of CHD such as coarctation of aorta in future.
Collapse
Affiliation(s)
- Yulei Zhu
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhong Shan Er Lu, Guangzhou, 510080, Guangdong, China.,School of Medicine, South China University of Technology, Guangzhou, 510006, Guangdong, China
| | - Rui Chen
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhong Shan Er Lu, Guangzhou, 510080, Guangdong, China.,School of Medicine, South China University of Technology, Guangzhou, 510006, Guangdong, China
| | - Yu-Hsiang Juan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou Chang Gung University, Taoyuan, Taiwan
| | - He Li
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhong Shan Er Lu, Guangzhou, 510080, Guangdong, China
| | - Jingjing Wang
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhong Shan Er Lu, Guangzhou, 510080, Guangdong, China.,School of Medicine, South China University of Technology, Guangzhou, 510006, Guangdong, China
| | - Zhuliang Yu
- School of Medicine, South China University of Technology, Guangzhou, 510006, Guangdong, China. .,College of Automation Science and Technology, South China University of Technology, 381 Wushan Road, Guangzhou, 510080, Guangdong, China.
| | - Hui Liu
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, No. 106, Zhong Shan Er Lu, Guangzhou, 510080, Guangdong, China. .,School of Medicine, South China University of Technology, Guangzhou, 510006, Guangdong, China.
| |
Collapse
|