A Survey of Quantitative Descriptors of Arterial Flows

Gallo, Diego; Isu, Giuseppe; Massai, Diana Nada Caterina; Pennella, Francesco; Deriu, Marco Agostino; Ponzini, Raffaele; Bignardi, Cristina; Audenino, Alberto; Rizzo, Giovanna; Morbiducci, Umberto

doi:10.1007/978-94-007-7769-9_1

Cited by 5 publications

(3 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The time-averaged wall shear stress (TAWSS), derived from CFD results, expressed the total amount of shear-stress experienced by the arterial wall throughout the cardiac cycle and was used to quantify local hemodynamic disturbances as described in previous publications ( 8 , 15 , 18 – 20 ).…”

Section: Methodsmentioning

confidence: 99%

Linking Aortic Mechanical Properties, Gene Expression and Microstructure: A New Perspective on Regional Weakening in Abdominal Aortic Aneurysms

Forneris

Kennard

Ismaguilova

et al. 2021

Front. Cardiovasc. Med.

View full text Add to dashboard Cite

Background: Current clinical practice for the assessment of abdominal aortic aneurysms (AAA) is based on vessel diameter and does not account for the multifactorial, heterogeneous remodeling that results in the regional weakening of the aortic wall leading to aortic growth and rupture. The present study was conducted to determine correlations between a novel non-invasive surrogate measure of regional aortic weakening and the results from invasive analyses performed on corresponding ex vivo aortic samples. Tissue samples were evaluated to classify local wall weakening and the likelihood of further degeneration based on non-invasive indices.Methods: A combined, image-based fluid dynamic and in-vivo strain analysis approach was used to estimate the Regional Aortic Weakness (RAW) index and assess individual aortas of AAA patients prior to elective surgery. Nine patients were treated with complete aortic resection allowing the systematic collection of tissue samples that were used to determine regional aortic mechanics, microstructure and gene expression by means of mechanical testing, microscopy and transcriptomic analyses.Results: The RAW index was significantly higher for samples exhibiting lower mechanical strength (p = 0.035) and samples classified as low elastin content (p = 0.020). Samples with higher RAW index had the greatest number of genes differentially expressed compared to any constitutive metric. High RAW samples showed a decrease in gene expression for elastin and a down-regulation of pathways responsible for cell movement, reorganization of cytoskeleton, and angiogenesis.Conclusions: This work describes the first AAA index free of assumptions for material properties and accounting for patient-specific mechanical behavior in relation to aneurysm strength. Use of the RAW index captured biomechanical changes linked to the weakening of the aorta and revealed changes in microstructure and gene expression. This approach has the potential to provide an improved tool to aid clinical decision-making in the management of aortic pathology.

show abstract

Section: Methodsmentioning

confidence: 99%

Linking Aortic Mechanical Properties, Gene Expression and Microstructure: A New Perspective on Regional Weakening in Abdominal Aortic Aneurysms

Forneris

Kennard

Ismaguilova

et al. 2021

Front. Cardiovasc. Med.

View full text Add to dashboard Cite

show abstract

“…Each of these aspects is difficult to confront, and combined make quantification and interpretation of WSS onerous. This has resulted in development of various WSS parameters that each try to quantify different characteristics [4,5].…”

Section: Introductionmentioning

confidence: 99%

Characterizations and Correlations of Wall Shear Stress in Aneurysmal Flow

Arzani

Shadden

2015

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

Wall shear stress (WSS) is one of the most studied hemodynamic parameters, used in correlating blood flow to various diseases. The pulsatile nature of blood flow, along with the complex geometries of diseased arteries, produces complicated temporal and spatial WSS patterns. Moreover, WSS is a vector, which further complicates its quantification and interpretation. The goal of this study is to investigate WSS magnitude, angle, and vector changes in space and time in complex blood flow. Abdominal aortic aneurysm (AAA) was chosen as a setting to explore WSS quantification. Patient-specific computational fluid dynamics (CFD) simulations were performed in six AAAs. New WSS parameters are introduced, and the pointwise correlation among these, and more traditional WSS parameters, was explored. WSS magnitude had positive correlation with spatial/temporal gradients of WSS magnitude. This motivated the definition of relative WSS gradients. WSS vectorial gradients were highly correlated with magnitude gradients. A mix WSS spatial gradient and a mix WSS temporal gradient are proposed to equally account for variations in the WSS angle and magnitude in single measures. The important role that WSS plays in regulating near wall transport, and the high correlation among some of the WSS parameters motivates further attention in revisiting the traditional approaches used in WSS characterizations.

show abstract

“…The generation of atherosclerotic plaques seems to be related to spatial gradients of WSS, which increases cell division and induces cell migration away from the vessel wall . High values of spatial WSS gradients increase the permeability of the vessel wall, as well as endothelium dysfunction . Temporal WSS gradients seem to affect the proliferation of endothelium cells …”

Section: Introductionmentioning

confidence: 99%

Investigation of the hemodynamic flow conditions and blood‐induced stresses inside an abdominal aortic aneurysm by means of a SPH numerical model

Aricò

Sinagra

Nagy

et al. 2019

Numer Methods Biomed Eng

View full text Add to dashboard Cite

The estimation of blood flow-induced loads occurring on the artery wall is affected by uncertainties hidden in the complex interaction of the pulsatile flow, the mechanical parameters of the artery, and the external support conditions. To circumvent these difficulties, a specific tool is developed by combining the aorta displacements measured by an electrocardiogram-gated-computed tomography angiography, with the blood velocity field computed by a smoothed particle hydrodynamics (SPH) numerical model. In the present work, the SPH model has been specifically adapted to the solution of the 3D Navier-Stokes equations inside a domain with boundaries of prescribed motion. Images of the abdominal aorta aneurysm (AAA) of a 44-year-old female patient were acquired during a stabilized cardiac cycle by electrocardiogram-gated-computed tomography angiography. The in vivo kinematic field inside the pulsating arterial wall was estimated by using recent technology, which makes it possible to follow the shape of the arterial wall during a cardiac cycle. We compare the flow conditions and the blood-induced loads, computed by the numerical model under the assumption of a moving arterial wall, with the corresponding results obtained assuming three rigid wall geometries of the vessel during the cardiac cycle. Significant differences were found for the wall shear stress distribution. K E Y W O R D Saneurysm, arterial wall, infrarenal abdominal aorta, moving boundary, shear stresses, SPH | INTRODUCTIONAbdominal aortic aneurysms (AAAs) are localized and permanent dilatation of the infrarenal abdominal aorta. The related health risk is due to thrombus growth and development, rupture of the aortic wall, and degenerative effects of endothelial cells because of alteration of the flow field inside the aortic lumen. 1 The origin and development of AAAs are not clearly understood. The coupling between physiological changes of the intimal and medial layers of the arterial wall and the mechanical stimuli of the hemodynamic stresses acting on the vessel wall could be one of the origins. 2-5 Past studies 6,7 have shown that the "disturbed" flow conditions inside the lumen, such as regions of high and very low values of wall shear stress (WSS), and large temporal and spatial WSS gradients,

show abstract

A Survey of Quantitative Descriptors of Arterial Flows

Cited by 5 publications

References 90 publications

Linking Aortic Mechanical Properties, Gene Expression and Microstructure: A New Perspective on Regional Weakening in Abdominal Aortic Aneurysms

Linking Aortic Mechanical Properties, Gene Expression and Microstructure: A New Perspective on Regional Weakening in Abdominal Aortic Aneurysms

Characterizations and Correlations of Wall Shear Stress in Aneurysmal Flow

Investigation of the hemodynamic flow conditions and blood‐induced stresses inside an abdominal aortic aneurysm by means of a SPH numerical model

Contact Info

Product

Resources

About