Risk of rupture of the cerebral aneurysm in relation to traumatic brain injury using a patient-specific fluid-structure interaction model

2019 ◽  
Vol 176 ◽  
pp. 9-16 ◽  
Author(s):  
Reza Razaghi ◽  
Hasan Biglari ◽  
Alireza Karimi
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cerebral Aneurysm ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Patient Specific ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Risk Of Rupture

A patient-specific fluid–structure interaction model of the cerebrovascular damage in relation to traumatic brain injury

Trauma ◽  
2020 ◽  
pp. 146040862092172
Author(s):  
Reza Razaghi ◽  
Hasan Biglari ◽  
Alireza Karimi
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Arterial Wall ◽  
Considerable Increase ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Patient Specific ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Comprehensive Knowledge

Background There is a lack of knowledge on the magnitudes of the biomechanical stresses and deformations occurring in the cerebral arterial wall after traumatic brain injury (TBI). Experimental techniques are unable to calculate the stresses and deformations in the cerebral arterial wall after TBI; therefore, the application of numerical simulations, such as finite element modeling, is preferred. Methods This study was aimed to calculate the stresses and deformations as well as the alteration in the pressure and velocity of the blood in the cerebrovascular artery using a fluid–structure interaction model. Results The results revealed considerable increase in the pressure and velocity of the blood which might lead to cerebrovascular damage followed by hemorrhage. The arterial wall showed the highest deformation of 0.047 mm in the X direction which was higher than that in the Y (0.035–0.050 mm) and Z (0.019–0.030 mm) directions. Conclusions These results have implications not only for the understanding of the stresses and deformations in the cerebral artery because of TBI, but also for providing a comprehensive knowledge for biomechanical and medical experts in regard to thresholds of cerebrovascular damage for use in establishing preventive and/or treatment methods.

Risk of Rupture in Abdominal Aortic Aneurysms and Vulnerable Plaques: A Patient Based Fluid Structure Interaction Approach

2008 ◽  
Author(s):  
Danny Bluestein ◽  
Yared Alemu ◽  
Michalis Xenos ◽  
Peter Rissland ◽  
Jawaad Sheriff ◽  
...  
Keyword(s):  
Vulnerable Plaque ◽  
Fluid Structure Interaction ◽  
Material Model ◽  
Patient Specific ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Fibrous Cap ◽  
Vulnerable Plaques ◽  
Abdominal Aortic ◽  
Risk Of Rupture

In this study we performed two separate fluid structure interaction (FSI) simulations. A patient-specific Abdominal Aortic Aneurysm (AAA) geometry, and coronary vulnerable plaque (VP) geometry in idealized and in patient based geometries reconstructed from intravascular (IVUS) measurements. The patient specific AAA FSI simulations were carried out with both isotropic and anisotropic wall properties. An orthotropic material model was used to describe wall properties, closely approximating experimental results of AAA specimens [1]. The results predict larger deformations and stress values for the anisotropic material model as compared to the isotropic one. This difference indicates that the isotropic formulation may underestimate the risk of rupture. The ability to quantify stresses developing within the aneurysm wall based on FSI simulations will help clinicians to reach informed decisions in determining rupture risk of AAA and the need for surgical intervention. The risk of rupture of vulnerable plaques was studied in both idealized and patient specific geometries using FSI simulations. The idealized model included vessel wall, fibrous cap, and a lipid core. Regions susceptible to failure and the contribution of the various components were studied. The upstream side of the vulnerable plaque fibrous cap had the highest stresses. The presence of a calcified spot embedded within the fibrous cap proper was studied, and was demonstrated to enhance stresses within the fibrous cap, significantly contributing to its risk of rupture.

A Patient Based Approach for Fluid Structure Interaction in Ruptured Abdominal Aortic Aneurysms

2009 ◽  
Author(s):  
Michalis Xenos ◽  
Suraj Rambhia ◽  
Yared Alemu ◽  
Shmuel Einav ◽  
John J. Ricotta ◽  
...  
Keyword(s):  
Fluid Structure Interaction ◽  
Wall Stress ◽  
Material Model ◽  
Aortic Aneurysms ◽  
Patient Specific ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Bifurcation Angle ◽  
Risk Of Rupture ◽  
Iliac Bifurcation

Fluid structure interaction (FSI) simulations were conducted to assess the risk of rupture in reconstructed AAA from patients who had contained ruptured AAAs. The goal was to test to ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the actual rupture location. We also present a parametric study in which the relationship of iliac bifurcation angle and the role of embedded calcifications were studied in respect to the aneurismal wall stress. The patient specific AAA FSI simulations were carried out with advanced constitutive material models of the various components of AAA, including models that describe the wall anisotropy, structural strength based on collagen fibers orientation within the arterial wall, AAA intraluminal thrombus (ILT), and embedded calcifications. The anisotropic material model used to describe the wall properties closely correlated with experimental results of AAA specimens [1]. The results demonstrate that the region of rupture can be predicted by the region of the highest wall stress distribution. Embedded wall calcifications increase the local wall stress surrounding calcified spots, and eventually increases the risk of rupture. FSI results in streamlined AAA geometries show that the maximum stress on the aneurismal wall increases as the iliac bifurcation angle increases.

scholarly journals Development of a Patient-Specific Cerebral Vasculature Fluid-Structure-Interaction Model

2021 ◽  
Author(s):  
Kevin Mattheus Moerman ◽  
Praneeta Konduri ◽  
Behrooz Fereidoonnezhad ◽  
Henk Marquering ◽  
Aad van der Lugt ◽  
...  
Keyword(s):  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Ct Images ◽  
Patient Specific ◽  
Clinical Images ◽  
Cerebral Vessel ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Technical Challenges ◽  
In Silico Models

Development of in silico models of patient-specific cerebral artery networks presents several significant technical challenges: (i) The resolution and smoothness of medical CT images is much lower than the required element/cell length for FEA/CFD/FSI models; (ii) contact between vessels, and indeed self contact of high tortuosity vessel segments are not clearly identifiable from medical CT images. Commercial model construction software does not provide customised solutions for such technical challenges, with the result that accurate, efficient and automated development of patient-specific models of the cerebral vessels is not facilitated. This paper presents the development of a customised and automated platform for the generation of high resolution patient-specific FEA/CFD/FSI models from clinical images. This platform is used to perform the first fluid-structure-interaction patient-specific analysis of blood flow and artery deformation of an occluded cerebral vessel. Results demonstrate that in addition to flow disruption, clot occlusion significantly alters the geometry and strain distribution in the vessel network, with the blocked M2 segment undergoing axial elongation.The new computational approach presented in this study can be further developed as a clinical diagnostic tool and as a platform for thrombectomy device design.

A Fluid Structure Interaction Approach for Patient Based Abdominal Aortic Aneurysm Rupture Risk Prediction

2010 ◽  
Author(s):  
Michalis Xenos ◽  
Suraj Rambhia ◽  
Yared Alemu ◽  
Shmuel Einav ◽  
John J. Ricotta ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Fluid Structure Interaction ◽  
Patient Specific ◽  
Rupture Risk ◽  
Material Models ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Abdominal Aortic ◽  
Risk Of Rupture

Fluid structure interaction (FSI) simulations of patient-specific fusiform non-ruptured and contained ruptured Abdominal Aortic Aneurysm (AAA) geometries were conducted. The goals were: (1) to test the ability of our FSI methodology to predict the location of rupture, by correlating the high wall stress regions with the rupture location, (2) estimate the state of the pathological condition by calculating the ruptured potential index (RPI) of the AAA and (3) predict the disease progression by comparing healthy and pathological aortas. The patient specific AAA FSI simulations were carried out with advanced constitutive material models of the various components of AAA, including models that describe wall anisotropy based on collagen fibers orientation within the arterial wall, structural strength of the aorta, intraluminal thrombus (ILT), and embedded calcifications. The anisotropic material model used to describe the wall properties closely correlated with experimental results of AAA specimens. The results demonstrate that the anisotropic wall simulations showed higher peak wall stresses as compared to isotropic material models, indicating that the latter may underestimate the AAA risk of rupture. The ILT appeared to provide a cushioning effect reducing the stresses, while small calcifications (small-Ca) appeared to weaken the wall and contribute to the rupture risk. FSI simulations with ruptured AAA demonstrated that the location of the maximal wall stresses and RPI overlap the actual rupture region.

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