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

Compliant vascular grafts and methods of use

Compliant vascular grafts for implantation in the vasculature are provided. The compliant vascular grafts are designed to expand longitudinally and radially within a blood vessel, such as an artery, and is expected to be particularly well suited for treati ...

2024

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

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

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

Hemodynamic effects of a dielectric elastomer augmented aorta on aortic wave intensity: An in-vivo study

Yves Perriard, Yoan René Cyrille Civet, Silje Ekroll Jahren, Thomas Guillaume Martinez, Francesco Clavica, Armando Matthieu Walter, Lorenzo Ferrari

Dielectric elastomer actuator augmented aorta (DEA) represents a novel approach with high potential for assisting a failing heart. The soft tubular device replaces a section of the aorta and increases its diameter when activated. The hemodynamic interactio ...

2023

Design and computational optimization of compliance-matching aortic grafts

Nikolaos Stergiopoulos, Vasiliki Bikia, Georgios Rovas

Introduction: Synthetic vascular grafts have been widely used in clinical practice for aortic replacement surgery. Despite their high rates of surgical success, they remain significantly less compliant than the native aorta, resulting in a phenomenon calle ...

FRONTIERS MEDIA SA2023

The Impact of Left Ventricular Performance and Afterload on the Evaluation of Aortic Valve Stenosis: A 1D Mathematical Modeling Approach

Nikolaos Stergiopoulos

The transaortic valvular pressure gradient (TPG) plays a central role in decision-making for patients suffering from severe aortic stenosis. However, the flow-dependence nature of the TPG makes the diagnosis of aortic stenosis challenging since the markers ...

MDPI2023

Arterial Wave Reflection and Aortic Valve Stenosis: Diagnostic Challenges and Prognostic Significance

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou, Vasiliki Bikia, Georgios Rovas

IntroductionArterial wave reflection is an important component of the left ventricular afterload, affecting both pressure and flow to the aorta. The aim of the present study was to evaluate the impact of wave reflection on transvalvular pressure gradients ...

FRONTIERS MEDIA SA2022

Validation of a Non-invasive Inverse Problem-Solving Method for Stroke Volume

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou, Emma Marie Roussel, Vasiliki Bikia, Georgios Rovas

Stroke volume (SV) is a major biomarker of cardiac function, reflecting ventricular-vascular coupling. Despite this, hemodynamic monitoring and management seldomly includes assessments of SV and remains predominantly guided by brachial cuff blood pressure ...

FRONTIERS MEDIA SA2022

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

Georges Wagnières, Séverine Marguerite Urfer, Jaroslava Joniová

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

In situ photopolymerizable hydrogels for intracranial aneurysms treatment

Oriane Poupart

Intracranial aneurysm is a cerebrovascular disease characterized by an artery dilation in the brain. An aneurysm is prone to rupture, which causes a life-threatening subarachnoid hemorrhage. The major drawbacks of the current treatments, open surgical clip ...

EPFL2021

Pulsatile Flow-Induced Fatigue-Resistant Photopolymerizable Hydrogels for the Treatment of Intracranial Aneurysms

Dominique Pioletti, Andreas Schmocker, Lucio Feo Pancaldi-Giubbini, Christophe Moser, Mahmut Selman Sakar, Oriane Poupart

An alternative intracranial aneurysm embolic agent is emerging in the form of hydrogels due to their ability to be injected in liquid phase and solidify in situ. Hydrogels have the ability to fill an aneurysm sac more completely compared to solid implants ...

2021

Follicular regulatory helper T cells control the response of regulatory B cells to a high-cholesterol diet

Nikolaos Stergiopoulos

Aims B cell functions in the process of atherogenesis have been investigated but several aspects remain to be clarified. ...

OXFORD UNIV PRESS2021

Determination of Aortic Characteristic Impedance and Total Arterial Compliance From Regional Pulse Wave Velocities Using Machine Learning: An in-silico Study

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou, Vasiliki Bikia, Georgios Rovas

In-vivo assessment of aortic characteristic impedance (Zao) and total arterial compliance (CT) has been hampered by the need for either invasive or inconvenient and expensive methods to access simultaneous recordings of aortic pressure and flow, wall thick ...

2021

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

Nikolaos Stergiopoulos, Bram Trachet, Lydia Aslanidou, 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

Cardiotrophin-1 Deficiency Abrogates Atherosclerosis Progression

Nikolaos Stergiopoulos, Rodrigo Araujo Fraga Da Silva

Cardiotrophin-1 (CT-1) is associated with cardiovascular (CV) diseases. We investigated the effect of CT-1 deficiency in the development and progression of atherosclerosis in double knockout Apoe(-/-)ct-1(-/-) mice. Apoe(-/-) C57Bl/6 or Apoe(-/-)ct-1(-/-) ...

Nature Research2020

The effect of the elongation of the proximal aorta on the estimation of the aortic wall distensibility

Nikolaos Stergiopoulos, Bram Trachet, Stamatia Zoi Pagoulatou, Mauro Ferraro, Vasiliki Bikia, Georgios Rovas

The compliance of the proximal aortic wall is a major determinant of cardiac afterload. Aortic compliance is often estimated based on cross-sectional area changes over the pulse pressure, under the assumption of a negligible longitudinal stretch during the ...

2021

Acute effects of transcatheter aortic valve replacement on the ventricular-aortic interaction

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou, Vasiliki Bikia, Georgios Rovas

Transcatheter aortic valve replacement (TAVR) is increasingly used to treat severe aortic stenosis (AS) patients. However, little is known regarding the direct effect of TAVR on the ventricular-aortic interaction. In the present study, we aimed to investig ...

AMER PHYSIOLOGICAL SOC2020

Noninvasive estimation of aortic hemodynamics and cardiac contractility using machine learning

Nikolaos Stergiopoulos, Stamatia Zoi Pagoulatou, Vasiliki Bikia, Georgios Rovas

Cardiac and aortic characteristics are crucial for cardiovascular disease detection. However, noninvasive estimation of aortic hemodynamics and cardiac contractility is still challenging. This paper investigated the potential of estimating aortic systolic ...

Nature Research2020

Long noncoding RNA SNHG12 integrates a DNA-PK-mediated DNA damage response and vascular senescence

Johan Auwerx, Norman Lionel Moullan, Lei Chen

Long noncoding RNAs (lncRNAs) are emerging regulators of biological processes in the vessel wall; however, their role in atherosclerosis remains poorly defined. We used RNA sequencing to profile lncRNAs derived specifically from the aortic intima of Ldlr(- ...

AMER ASSOC ADVANCEMENT SCIENCE2020

In vitro Implementation of Photopolymerizable Hydrogels as a Potential Treatment of Intracranial Aneurysms

Dominique Pioletti, Andreas Schmocker, Christophe Moser, Oriane Poupart

Intracranial aneurysms are increasingly being treated with endovascular therapy, namely coil embolization. Despite being minimally invasive, partial occlusion and recurrence are more frequent compared to open surgical clipping. Therefore, an alternative tr ...

2020