Publications associées à Vascular bypass

Novel theory and potential applications of central diastolic pressure decay time constant

Nikolaos Stergiopoulos, Georgios Rovas, Sokratis Anagnostopoulos, Vasiliki Bikia, Patrick Segers

Central aortic diastolic pressure decay time constant ( ) is according to the two-element Windkessel model equal to the product of total peripheral resistance (R) times total arterial compliance (C ). As such, it is related to arterial stiffness, which has ...

2024

Compliance-matching vascular grafts with personalization potential

Georgios Rovas

Aortic diseases are characterized by dire prognosis and inadequate diagnosis, owing to their insidious yet lethal nature. Aortopathies, namely aortic aneurysms and dissections, along with certain congenital diseases, might necessitate surgical replacement ...

EPFL2023

Targeted capillary photothrombosis via multiphoton excitation of Rose Bengal

Paul James Marchand

Microvascular stalling, the process occurring when a capillary temporarily loses perfusion, has gained increasing interest in recent years through its demonstrated presence in various neuropathologies. Studying the impact of such stalls on the surrounding ...

2023

Sodium thiosulfate, a source of hydrogen sulfide, stimulates endothelial cell proliferation and neovascularization

Georges Wagnières, Jaroslava Joniová, Séverine Marguerite Urfer

Therapies to accelerate vascular repair are currently lacking. Pre-clinical studies suggest that hydrogen sulfide (H2S), an endogenous gasotransmitter, promotes angiogenesis. Here, we hypothesized that sodium thiosulfate (STS), a clinically relevant source ...

FRONTIERS MEDIA SA2022

Early Morphofunctional Changes in AngII-Infused Mice Contribute to Regional Onset of Aortic Aneurysm and Dissection

Nikolaos Stergiopoulos, Lydia Aslanidou, Bram Trachet, Goran Lovric

Aortic aneurysms and dissections are silent and lethal conditions, whose pathogenesis remains incompletely understood. Although angiotensin II (AngII)-infused ApoE-/- mice have been widely used to study aortic aneurysm and dissection, early morphofunctiona ...

KARGER2020

Metabolic fingerprints discriminating severity of acute ischemia using in vivo high-field H-1 magnetic resonance spectroscopy

Mario Gaetano Lepore, Hongxia Lei, Lara Buscemi Estefanell

Despite the improving imaging techniques, it remains challenging to produce magnetic resonance (MR) imaging fingerprints depicting severity of acute ischemia. The aim of this study was to evaluate the potential of the overall high-field H-1 MR Spectroscopy ...

Wiley-Blackwell2020

Mapping the site-specific accuracy of loop-based local pulse wave velocity estimation and reflection magnitude: a 1D arterial network model analysis

Nikolaos Stergiopoulos, Patrick Segers

Objective: Local pulse wave velocity (PWV) can be estimated from the waterhammer equation and is an essential component of wave separation analysis. However, previous studies have demonstrated inaccuracies in the estimations of local PWV due to the presenc ...

2019

How Flow Reduction Influences the Intracranial Aneurysm Occlusion: A Prospective 4D Phase-Contrast MRI Study

Mohamed Farhat, Philippe Reymond, Pierre Bouillot

BACKGROUND AND PURPOSE: Flow-diverter stents are widely used for the treatment of wide-neck intracranial aneurysms. Various parameters may influence intracranial aneurysm thrombosis, including the flow reduction induced by flow-diverter stent implantation, ...

American Society of Neuroradiology (ASNR)2019

A systematic review and meta-analysis of the efficacy of aortic anastomotic devices

Nikolaos Stergiopoulos, Dimitrios Schizas

Objective: One of the factors contributing to complications related to open repair of the aorta is the construction of a hand-sewn anastomosis. Aortic anastomotic devices (AADs), such as the intraluminal ringed graft (IRG), and the anastomotic stenting tec ...

MOSBY-ELSEVIER2019

Co-localization of microstructural damage and excessive mechanical strain at aortic branches in Angiotensin-II-infused mice

Nikolaos Stergiopoulos, Lydia Aslanidou, Bram Trachet, Goran Lovric, Mauro Ferraro, Patrick Segers

Animal models of aortic aneurysm and dissection can enhance our limited understanding of the etiology of these lethal conditions particularly because early-stage longitudinal data are scant in humans. Yet, the pathogenesis of often-studied mouse models and ...

2019

Computational study of the risk of restenosis in coronary bypasses

Alfio Quarteroni, Christian Vergara

Coronary artery disease, caused by the buildup of atherosclerotic plaques in the coronary vessel wall, is one of the leading causes of death in the world. For high-risk patients, coronary artery bypass graft is the preferred treatment. Despite overall exce ...

Springer Heidelberg2017

A Monolithic Approach to Fluid–Composite Structure Interaction

Simone Deparis, Davide Forti, Annalisa Quaini

We study a nonlinear fluid–structure interaction (FSI) problem between an incompressible, viscous fluid and a composite elastic structure consisting of two layers: a thin layer (membrane) in direct contact with the fluid, and a thick layer (3D linearly ela ...

Springer Verlag2017

A computational fluid-structure interaction analysis of coronary Y-grafts

Alfio Quarteroni, Christian Vergara

Coronary artery disease is one of the leading causes of death worldwide. The stenotic coronary vessels are generally treated with coronary artery bypass grafts (CABGs), which can be either arterial (internal mammary artery, radial artery) or venous (saphen ...

Elsevier Sci Ltd2017

Imaging of the stroke-related changes in the vascular system of the mouse brain with the use of extended focus Optical Coherence Microscopy

Theo Lasser, Daniel Pawel Szlag

We used Optical Coherence Microscopy (OCM) to monitor structural and functional changes due to ischemic stroke in small animals brains in vivo. To obtain lateral resolution of 2.2 μm over the range of 600 μm we used extended focus configuration of OCM inst ...

SPIE digital Library2016

Intra-aneurysmal hemodynamics: evaluation of pCONus and pCANvas bifurcation aneurysm devices using DSA optical flow imaging

Pierre Bouillot

Background Implantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging sten ...

BMJ2015

Novel non-invasive techniques for hemodynamic monitoring

Orestis Vardoulis

The monitoring of hemodynamic parameters is crucial for optimal patient management and treatment. However, established methods are often invasive and possibly inapplicable to sensitive age groups. Novel, non-invasive techniques have the potential to transf ...

EPFL2014

The chicken chorioallantoic membrane model in biology, medicine and bioengineering

Patrycja Nowak-Sliwinska

The chicken chorioallantoic membrane (CAM) is a simple, highly vascularized extraembryonic membrane, which performs multiple functions during embryonic development, including but not restricted to gas exchange. Over the last two decades, interest in the CA ...

Springer2014

Local in vivo optical measurements of neurometabolic and neurovascular coupling mechanisms in the rodent cortex

Elena Migacheva

This thesis introduces a novel approach for in vivo separation and quantification of spatio-temporal dynamics of optical coefficients (absorption, scattering), oxygen saturation (SO2) and haemoglobin concentrations within rat brain somatosensory cortex und ...

EPFL2012

Impact of Aortic Grafts on Arterial Pressure: A Computational Fluid Dynamics Study

Nikolaos Stergiopoulos, Philippe Reymond, Orestis Vardoulis, Bryn Andrew Martin, Eline Coppens

Objective: Vascular prostheses currently used in vascular surgery do not have the same mechanical properties as human arteries. This computational study analyses the mechanisms by which grafts, placed in the ascending aorta (proximal) and descending aorta ...

Elsevier2011

Biomechanical, morphological and zero-stress state characterization of jugular vein remodeling in arteriovenous fistulas for hemodialysis

Nikolaos Stergiopoulos

While the role of hemodynamic variables on the development of intimal hyperplasia in arteriovenous fistulas for hemodialysis has been examined, less is known about the intramural biomechanical factors. In this study, arteriovenous fistulas were created by ...

2010