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AArteMIS

Aneurysmal Arterial Mechanics: Into the Structure


ERC Starting Grant funding n°638804

Principal Investigator: Dr. Pierre BADEL

 

AArteMIS is a five year research project started in 2015 which aims to understand, describe and quantify the mechanisms underpinning arterial rupture, which are still totally unknown.

The project is led by Dr. Pierre Badel and gathers about 15 researchers involving permanent faculty, postdocs and PhD students.
It is funded by the European Research Council (ERC) which attributed a grant of 1.5 million euros to P. Badel in 2015 (ERC-2014-StG 638804).

The rationale behind AArteMIS

The rupture of an Aortic Aneurysm (AA), which is often lethal, is a biomechanical phenomenon that occurs when the wall stress state exceeds the local strength of the tissue. Current understanding of arterial rupture mechanisms is poor, as the physics taking place at the microscopic scale in collagenous structures remains an open area of research.


Background of the group

The PI's group was recently able to detect, in advance, at the macro-scale, rupture-prone areas in bulging arterial tissues. The next step is to characterize the details of the arterial microstructure in order to elucidate the mechanisms controlling the rupture response.


Approach

Through the achievements of AArteMIS, the local mechanics of the tissue, especially close to its rupture state, will be quantitatively analyzed using in situ mechanical tests performed in multi-photon confocal microscopy and X-ray micro-tomography environments. Then the local mechanical state of the structure will be numerically reconstructed to establish quantitative micro-scale rupture criteria. AArteMIS will also address micro-macro modelling based on the collected data.
The entire project will be completed through collaboration with medical doctors and engineers, experts in all required fields for the success of AArteMIS.


Roadmap

The main steps of the research implemented in AArteMIS are described in what follows.

1 - Development of original experiments
Aim: In situ mechanical testing of arterial tissue within 3D imaging devices allowing to reconstructing the internal structure of opaque materials

2 - Acquisition and analysis of 3D images of arterial specimens
Aim: qualitative and quantitative analysis of the microstructural images, hence relating microstructure evolutions to the mechanical loading applied.

3 - Numerical reconstruction of the microstructures
Aim: images cannot provide the whole mechanical state (stresses, forces) of the microstructure observed. Numerical techniques will be implemented to obtain this information.

4 - Implementation of the results in multi-scale homogenization models
Aim: including the previous results and findings in such models will enable use of these findings in a clinical context at the stage of diagnosis of arterial rupture risk.


AArtemIS team

Faculty and permanent staff members at Center for Biomedical and Healhcare Engineering

  1. Dr BADEL Pierre (Principal investigator)
  2. Prof AVRIL Stéphane
  3. Prof MOLIMARD Jérôme
  4. Dr MORIN Claire
  5. Faculty and permanent staff members at Saint-Etienne University Hospital

    1. MD PhD DUPREY Ambroise
    2. Faculty and permanent staff members at CNRS Lab. 3S-R, Grenoble, France

      1. Prof GEINDREAU Christian
      2. Dr ORGEAS Laurent (CNRS Res. Dir.)
      3. Collaboration with members of CNRS lab MATEIS, INSA Lyon, France

        1. Dr MAIRE Éric (CNRS Res. Dir.)
        2. Dr ADRIEN Jérôme (CNRS Res. Dir.)
        3. Post-doc fellows

          1. Dr DIDIER Clémentine
            Clémentine spent one year in the group and led the development of the experimental testing benches to be used in situ in a multiphoton confocal microscopy setup or in X-ray micro-tomography
          2. Dr BIANCHI Daniele
            Daniel joined the group in 2018 and leads the implementation and validation of a multi-scale homogenization model in a FE model setup
          3. PhD students

            1. CAVINATO Cristina
              Cristina was involved in developing and performing microscopy experiments as well as other mechanical tests on the specimens collected from the Hospital group. She develops the associated methods to improve and analyze the images of the arterial microstructure obtained.
            2. AYYALASOMAYAJULA Venkat Siva Radha Krishna
              Radha recently joined the group to work on the numerical reconstruction of arterial microstructures and their mechanical state during the in situ loading imposed in the experiments.
            3. BRUNET Joseph
              Joseph works on obtaining and analyzing data from in situ mechanical testing of arteries in an X-ray micro-tomography environment. In particular the mechanisms of medial dissection are investigated in this work.

            4. Communication

              Journal articles

              Brunet J, Pierrat B, Adrien J, Maire E, Badel P. A combined experimental-numerical lamellar-scale approach of tensile rupture in arterial medial tissue using X-ray tomography. Journal of the Mechanical Behavior of Biomedical Materials, 2019, in press. Manuscript coming soon.

              Helfenstein-Didier C, Taïnoff D, Viville J, Adrien J, Maire E, Badel P.. Tensile rupture of medial arterial tissue studied by X-ray micro-tomography on stained samples. Journal of the Mechanical Behavior of Biomedical Materials, 2018, 78:362-368. Manuscript in Open Access.

              F. Condemi F, Campisi S, Viallon M, Troalen T, Xuexin G, Barker AJ, Markl M, Croisille P, Trabelsi O, Cavinato C, Duprey A, Avril S. Fluid- and Biomechanical Analysis of Ascending Thoracic Aorta Aneurysm with Concomitant Aortic Insufficiency. Annals of Biomedical Engineering, 2017, 45:2921-2932.

              Cavinato C, Helfenstein-Didier C, Olivier T, Rolland du Roscoat S, Laroche N, Badel P. Biaxial loading of arterial tissues with 3D in situ observations of adventitia fibrous microstructure: a method coupling multi-photon confocal microscopy and bulge inflation test. Journal of the Mechanical Behavior of Biomedical Materials, 2017, 74:488-498. Manuscript in Open Access.


              Book chapters

              Cavinato C, Badel P, Krasny W, Avril S, Morin C. Experimental characterization of adventitial collagen fiber kinematics using second harmonic generation imaging microscopy: similarities and differences across arteries, species and testing conditions. . In Zhang KY (Ed.), Multi-Scale Extracellular Matrix Mechanics and Mechanobiology, in the series by Gefen A., Studies in Mechanobiology, Tissue Engineering and Biomaterials, Springer-Verlag, to be published in 2019.


              Conference communications

              Cavinato C, Helfenstein-Didier C, Olivier T, Badel P.  In situ microscopic investigation of arterial tissue during a bulge inflation test. 23rd Congress of the European Society of Biomechanics, July 2 - 5, 2017, Seville, Spain.

              Cavinato C, Helfenstein-Didier C, Olivier T, Badel P.  A new experimental approach to characterize arterial deformation micro-mechanisms. EUROMECH Colloquium 585: Advanced experimental methods in tissue biomechanics. February 12–16, 2017, Burg Warberg, Germany.

              Cavinato C, Helfenstein-Didier C, Olivier T, Badel P.  A new experimental approach to characterize arterial deformation micro-mechanisms. ESB-ITA Thematic Conference 2016, September 8-9, 2016, Palermo, Italy.

              Helfenstein-Didier C, Taïnoff D, Viville J, Adrien J, Maire E, Badel P.  In situ tensile tests of medial arterial tissue in x-ray microtomography. 22nd Congress of the European Society of Biomechanics, July 10-13, 2016, Lyon, France.