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Stula Ivana I Diagnostic and Interventional Radiology, University Hospital Split, Split, Croatia, - - 2014
Testicular flow studies after hernia mesh repair mostly showed different outcomes. The reason of infertility in some men after hernia repair is immunological factors. Aim of the study was to investigate the influence of mesh hernia repair on antisperm antibodies production and testicular blood flow and a connection among these ...
Gallo Diego D Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, - - 2014
Parallel to the massive use of image-based computational hemodynamics to study the complex flow establishing in the human aorta, the need for suitable experimental techniques and ad hoc cases for the validation and benchmarking of numerical codes has grown more and more. Here we present a study where the 3D ...
Ugron Adám - - 2014
Flow diverters (FDs) have been successfully applied in the recent decade to the treatment of intracranial aneurysms by impairing the communication between the flows in the parent artery and the aneurysm and, thus, the blood within the aneurysm sac. It would be desirable to have a simple and accurate computational ...
Gulan Utku - - 2014
A three-dimensional pulsatile aortic flow in a human ascending aorta is studied to investigate the effect of the aortic stiffness on the flow field and turbulent fluctuating velocities in the ascending aorta. A non-intrusive optical measurement technique, 3D Particle Tracking Velocimetry (3D-PTV), has been applied to anatomically accurate phantoms under ...
Benz Tobias - - 2014
Flow diversion is an emerging endovascular treatment option for cerebral aneurysms. Quantitative assessment of hemodynamic changes induced by flow diversion can aid clinical decision making in the treatment of cerebral aneurysms. In this article, besides summarizing past key research efforts, we propose a novel metric for the angiographic assessment of ...
Cebral Juan R JR Center for Computational Fluid Dynamics College of Sciences, George Mason University, Fairfax, VA, - - 2014
Quantification and characterization of the hemodynamic environment created after flow diversion treatment of cerebral aneurysms is important to understand the effects of flow diverters and their interactions with the biology of the aneurysm wall and the thrombosis process that takes place subsequently. This paper describes the construction of multi-modality image-based ...
Lee Cheng-Hung CH Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital-Linkou, Tao-Yuan, Taiwan ; Department of Mechanical Engineering, Chang Gung University, Tao-Yuan, - - 2014
This study investigates the helical secondary flows in the aortic arch using finite element analysis. The relationship between helical flow and the configuration of the aorta in patients of whose three-dimensional images constructed from computed tomography scans was examined. A finite element model of the pressurized root, arch, and supra-aortic ...
Retarekar Rohini R a Department of Biomedical Engineering , University of Iowa , Iowa City , IA 52242 , - - 2014
Indices of the intra-aneurysm hemodynamic environment have been proposed as potentially indicative of their longitudinal outcome. To be useful, the indices need to be used to stratify large study populations and tested against known outcomes. The first objective was to compile the diverse hemodynamic indices reported in the literature. Furthermore, ...
Wang Lifang - - 2014
Hemodynamics plays a crucial role in the formation, progression and rupture of intracranial aneurysms. Understanding these mechanisms is important to improve current diagnosis and treatment of intracranial aneurysms. In this study we simulate and analyze the pressure gradients and the blood flow fields in growing intracranial aneurysms. Firstly, the pressure ...
Jiménez Juan M JM Department of Pathology and Laboratory Medicine, University of Pennsylvania, , Philadelphia, PA 19104, - - 2014
Drug eluting stents are associated with late stent thrombosis (LST), delayed healing and prolonged exposure of stent struts to blood flow. Using macroscale disturbed and undisturbed fluid flow waveforms, we numerically and experimentally determined the effects of microscale model strut geometries upon the generation of prothrombotic conditions that are mediated ...
Mut Fernando F Center for Computational Fluid Dynamics, College of Sciences, George Mason University Fairfax, Virginia, - - 2013
The purpose of this study was to investigate whether the occlusion time of cerebral aneurysms treated with flow diverters depends on the hemodynamic conditions created immediately after treatment. A case study of a pair of tandem intracranial aneurysms that were treated with flow-diverting devices and occluded at different times was ...
Köhler Benjamin - - 2013
Cardiovascular diseases (CVD) are the leading cause of death worldwide. Their initiation and evolution depends strongly on the blood flow characteristics. In recent years, advances in 4D PC-MRI acquisition enable reliable and time-resolved 3D flow measuring, which allows a qualitative and quantitative analysis of the patient-specific hemodynamics. Currently, medical researchers ...
Chong W - - 2013
BACKGROUND AND PURPOSE:Recent studies have shown promising results regarding intracranial aneurysms treated with flow diverters. However, these have had adverse effects, including delayed aneurysm occlusion, posttreatment symptoms, and rupture. The hemodynamic profiles of aneurysms treated with flow diverters were analyzed to determine the ones associated with successful and failed treatments.MATERIALS ...
McGah Patrick M - - 2013
Computational hemodynamic simulations of cerebral aneurysms have traditionally relied on stereotypical boundary conditions (such as blood flow velocity and blood pressure) derived from published values as patient-specific measurements are unavailable or difficult to collect. However, controversy persists over the necessity of incorporating such patient-specific conditions into computational analyses. We perform ...
Chen Jie - - 2013
Blood flow in human arteries has been investigated using computational fluid dynamics tools. This paper considers flow modeling through three aorta models reconstructed from cross-sectional magnetic resonance scans of female patients. One has the normal control configuration, the second has elongation of the transverse aorta, and the third has tortuosity ...
Muschenborn Andrea D - - 2013
Shape memory polymer (SMP) foams are being investigated as an alternative aneurysm treatment method to embolic coils. The goal of both techniques is the reduction of blood flow into the aneurysm and the subsequent formation of a stable thrombus, which prevents future aneurysm rupture. The purpose of this study is ...
Papalexopoulou N - - 2013
We report successful surgical treatment of type A aortic dissection in a Jehovah's Witness without the use of any blood products. An interposition graft replacement of the ascending aorta was carried out. This was under right axillo-atrial cardiopulmonary bypass with antegrade cerebral perfusion via right a subclavian and left carotid ...
Goel Akshay - - 2013
To assess if fully automated localization of the aorta can be achieved using phase contrast (PC) MR images. PC cardiac-gated MR images were obtained as part of a large population-based study. A fully automated process using the Hough transform was developed to localize the ascending aorta (AAo) and descending aorta ...
Evju Oyvind - - 2013
Recent computational fluid dynamics (CFD) studies relate abnormal blood flow to rupture of cerebral aneurysms. However, it is still debated how to model blood flow with sufficient accuracy. Common assumptions made include Newtonian behaviour of blood, traction free outlet boundary conditions and inlet boundary conditions based on available literature. These ...
Courtemanche Karim - - 2013
Background and objectives: Concern about allogeneic blood product cost and complications has prompted interest in blood conservation techniques. Intraoperative autotransfusion (IAT) is currently not used routinely by vascular surgeons in open elective infrareanl abdominal aortic aneurysm (AAA) repair. The objective of this study is to review our experience with IAT ...
Xenos Michalis - - 2013
A right-sided aorta is a rare malformation which may be associated with other various types of congenital heart disease. We utilised haemodynamic, echocardiographic measurements, computerised tomography and image reconstruction software packages that were integrated in a computational fluid dynamics model to determine blood flow patterns in patient-based aortas. In the ...
Morales Hernán G - - 2013
Endovascular coiling aims to isolate the aneurysm from blood circulation by altering hemodynamics inside the aneurysm and triggering blood coagulation. Computational fluid dynamics (CFD) techniques have the potential to predict the post-operative hemodynamics and to investigate the complex interaction between blood flow and coils. The purpose of this work is ...
Levitt M R - - 2013
BACKGROUND AND PURPOSE:Computational fluid dynamics modeling is useful in the study of the hemodynamic environment of cerebral aneurysms, but patient-specific measurements of boundary conditions, such as blood flow velocity and pressure, have not been previously applied to the study of flow-diverting stents. We integrated patient-specific intravascular blood flow velocity and ...
Sughimoto Koichi - - 2013
Aortic aneurysms may cause the turbulence of blood flow and result in the energy loss of the blood flow, while grafting of the dilated aorta may ameliorate these hemodynamic disturbances, contributing to the alleviation of the energy efficiency of blood flow delivery. However, evaluating of the energy efficiency of blood ...
Lantz Jonas - - 2013
The turbulent blood flow through an aortic coarctation in a 63-year old female patient was studied experimentally using magnetic resonance imaging (MRI), and numerically using computational fluid dynamics (CFD), before and after catheter intervention. Turbulent kinetic energy (TKE) was computed in the numerical model using large eddy simulation and compared ...
Hope Thomas A - - 2013
BACKGROUND: Over the past two decades elective valve-sparing aortic root replacement (V-SARR) has become more common in the treatment of patients with aortic root and ascending aortic aneurysms. Currently there are little data available to predict complications in the post-operative population. The study goal was to determine if altered flow ...
Leontiev Oleg - - 2013
PURPOSE: To investigate retrospectively the use of catheter-based intraaccess blood flow measurements as an adjunct to physical examination and fistulography in hemodialysis access interventions. MATERIALS AND METHODS: Among 1,540 dialysis interventions performed at a single institution in a 2.5-year period, 104 qualifying catheter-based flow measurements were made in 70 mature ...
Benk Christoph - - 2013
OBJECTIVES: Left ventricular assist devices (LVADs) have become an important treatment option for heart failure patients. However, altered blood flow patterns are suspected to affect perfusion in the aorta or cause structural changes to the aortic root, leading to regurgitation and valve dysfunction or thrombus formation. The purpose of this ...
Konoura Chikako - - 2013
Trifurcated arch grafts (3-branch grafts) are now being used to repair the thoracic aorta in addition to conventional arch grafts (4-branch grafts). The anatomical shape of the 3-branch graft is different from the original vessel, so it is necessary for clinical application to evaluate blood flow distribution in the graft ...
Yagi Takanobu T Center for Advanced Biomedical Sciences, Waseda University, Tokyo, Japan. - - 2013
This study experimentally investigated the instability of flow impingement in a cerebral aneurysm, which was speculated to promote the degradation of aneurysmal wall. A patient-specific, full-scale and elastic-wall replica of cerebral artery was fabricated from transparent silicone rubber. The geometry of the aneurysm corresponded to that found at 9 days ...
Chien Aichi - - 2013
BACKGROUND: Intracranial aneurysm flow diverting stents are a new endovascular treatment option for wide neck and large/giant aneurysms. Since August 2011, our center has integrated flow diverting stents into aneurysm treatment management. To further understand the effects of flow diverting stents, we developed the intracranial stent flow mapping program, which ...
Cheng Zhuo - - 2013
Type B aortic dissection can be acutely complicated by rapid expansion, rupture, and malperfusion syndromes. Short-term adverse outcomes are associated with failure of the false lumen to thrombose. The reasons behind false lumen patency are poorly understood, and the objective of this pilot study was to use computational fluid dynamics ...
Chien Aichi - - 2013
Studies have reported a correlation between blood flow dynamics in the cardiac cycle and vascular diseases, but research to analyze the dynamic changes of flow in cerebral aneurysms is limited. This quantitative study investigates the temporal changes in flow during a cardiac cycle (flow waveform) in different regions of aneurysms ...
Ortega J M JM Engineering Technologies Division, Lawrence Livermore National Laboratory, P.O. Box 808, L-090, Livermore, CA 94551, USA. - - 2013
Numerical simulations are performed on patient-specific basilar aneurysms that are treated with shape memory polymer (SMP) foam. In order to assess the post-treatment hemodynamics, two modeling approaches are employed. In the first, the foam geometry is obtained from a micro-CT scan and the pulsatile blood flow within the foam is ...
Kousera C A - - 2013
The development of an engineering transitional turbulence model and its subsequent evaluation and validation for some diseased cardiovascular flows have been suggestive of its likely utility in normal aortas. The existence of experimental data from human aortas, acquired in the early 1970s with catheter-mounted hot film velocimeters, provided the opportunity ...
Weichert Frank - - 2013
The occlusional performance of sole endoluminal stenting of intracranial aneurysms is controversially discussed in the literature. Simulation of blood flow has been studied to shed light on possible causal attributions. The outcome, however, largely depends on the numerical method and various free parameters. The present study is therefore conducted to ...
Anvari Maryam Sotoudeh - - 2012
BACKGROUND: Ascending aortic aneurysm is a life threatening conditions leading to surgery in many cases. Demonstrating risk factors for this disease is essential for development of screening strategies for high-risk populations. Blood group although described as a potential risk factor for abdominal aortic aneurysm, has not been addressed in patients ...
Babiker M H - - 2012
Although coil embolization is one of the most effective treatments for intracranial aneurysms (ICAs), the procedure is often unsuccessful. For example, an ICA may persist after coil embolization if deployed coils fail to block the flow of blood into the aneurysm. Unfortunately, the specific flow changes that are effected by ...
Pereira V M - - 2012
BACKGROUND AND PURPOSE:Flow-diverter stents modify intra-aneurysmal blood flow and induce the progressive thrombosis of intracranial aneurysms followed by stable vascular reconstruction. The aim of this study was to report a new method for the appraisal of intracranial blood flow from DSA performed during endovascular treatment procedures.MATERIALS AND METHODS:A cohort of ...
Kojima Masahiro - - 2012
Computer-based simulation is necessary to clarify the hemodynamics in brain aneurysm. Specifically for endovascular treatments, the effects of indwelling intravascular devices on blood stream need to be considered. The most recent technology used for cerebral aneurysm treatment is related to the use of flow diverters to reduce the amount of ...
Deplano Valérie - - 2012
An in vitro dynamics set-up of the flow in a compliant abdominal aortic aneurysm (AAA) model with an anterior posterior asymmetry, aorto-iliac bifurcation, and physiological inlet flow rate and outlet pressure waveforms was developed. The aims were first to show that the structural mechanical behavior of the used material to ...
Viklander Gertrud - - 2012
Earlier studies have indicated an association between blood group non-O and atherosclerosis related vascular diseases. Abdominal aortic aneurysm (AAA) is traditionally regarded as a consequence of atherosclerosis. The aim of the present study was to investigate the association between ABO blood groups and AAA with special regard to a relation ...
Müller J-D - - 2012
The flow in a cerebral aneurysm on the Anterior Communicating Artery is simulated based on patient medical imaging. The sensitivity of the flow pattern is assessed with respect to variation of outflow split and geometric parameters. A comparison is made between the results from unsteady pulsatile computations and steady-state computations. ...
Deger Melike - - 2013
Erythropoiesis-stimulating agents can reduce red blood cell transfusion rates in patients developing anemia while receiving chemotherapy. We investigated potential cost savings from reduced transfusion rates in patients starting darbepoetin alfa (DA) at higher versus lower hemoglobin (Hb) levels. Two systematic literature reviews were performed: transfusion outcomes in patients receiving DA ...
Du Zhaopeng - - 2012
In response to volume expansion, locally generated dopamine decreases proximal tubule reabsorption by reducing both Na/H-exchanger 3 (NHE3) and Na-K-ATPase activity. We have previously demonstrated that mouse proximal tubules in vitro respond to changes in luminal flow with proportional changes in Na(+) and HCO(3)(-) reabsorption and have suggested that this ...
Ishiguro Akio - - 2012
Background:Dopamine is one of the most frequently used inotropic drugs in neonatal intensive care units; however, it apparently does not improve outcomes in premature infants. Given that the ultimate aim of cardiovascular management is to stabilize and maintain organ perfusion, an understanding of dopamine's effects on organ blood flow will ...
Hahn Gitte H - - 2012
Aim:  Despite widespread use, effects of volume boluses and dopamine in hypotensive newborn infants remain controversial. We aimed to elucidate if hypovolemia alone impairs cerebral autoregulation (CA), and if dopamine affects cerebral vasculature. Methods:  In 12 piglets cerebral perfusion (laser-Doppler flux) and oxygenation (near-infrared spectroscopy) were examined during dopamine (20-50 ...
Garhofer Gerhard - - 2012
To characterize total retinal blood flow in a group of healthy subjects. Included in this study were 64 healthy volunteers. Retinal venous diameters were measured using a dynamic vessel analyzer. Retinal blood velocities were measured using bidirectional laser Doppler velocimetry. All vessels with a diameter of >60 μm entering the ...
Kyriakou Adamos - - 2012
This paper investigates the main characteristics of the magneto-hemodynamic (MHD) response for application as a biomarker of vascular blood flow. The induced surface potential changes of a volunteer exposed to a 3 T static B0 field of a magnetic resonance imaging (MRI) magnet were measured over time at multiple locations by ...
Glatz Andrew C - - 2012
Systemic-pulmonary collateral (SPC) flow occurs commonly in single ventricle patients after superior cavo-pulmonary connection, with unclear clinical significance. We sought to evaluate the association between SPC flow and acute post-Fontan clinical outcomes using a novel method of quantifying SPC flow by cardiac magnetic resonance (CMR) imaging. All patients who had ...
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