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Should the Proximal Part of a Bifurcated Aortic Graft be Kept as Short as Possible? A Computational Study Elucidates on Aortic Graft Hemodynamics for Various Main Body Lengths

  • Author Footnotes
    # Nikolaos Kontopodis and Konstantinos Tzirakis equally contributed to this work and share 1st authorship.
    Nikolaos Kontopodis
    Correspondence
    Correspondence to: Nikolaos Kontopodis, MD, MSc, PhD, Vascular Surgery Unit, University Hospital of Heraklion, Panepistimiou Street, Heraklion, 71500, GREECE.
    Footnotes
    # Nikolaos Kontopodis and Konstantinos Tzirakis equally contributed to this work and share 1st authorship.
    Affiliations
    Vascular Surgery Unit, Medical School, University of Crete, Heraklion, Crete, GREECE
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  • Author Footnotes
    # Nikolaos Kontopodis and Konstantinos Tzirakis equally contributed to this work and share 1st authorship.
    Konstantinos Tzirakis
    Footnotes
    # Nikolaos Kontopodis and Konstantinos Tzirakis equally contributed to this work and share 1st authorship.
    Affiliations
    Department of Mechanical Engineering, Hellenic Mediterranean University, Heraklion, Crete, GREECE
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  • Fotos Stylianou
    Affiliations
    Department of Mechanical & Manufacturing Engineering, University of Cyprus, Leukosia, CYPRUS
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  • Vasileios Vavourakis
    Affiliations
    Department of Mechanical & Manufacturing Engineering, University of Cyprus, Leukosia, CYPRUS

    Department of Medical Physics & Biomedical Engineering, University College of London, London, UK
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  • George M. Patou
    Affiliations
    Department of Mechanical Engineering, Hellenic Mediterranean University, Heraklion, Crete, GREECE
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  • Christos V. Ioannou
    Affiliations
    Vascular Surgery Unit, Medical School, University of Crete, Heraklion, Crete, GREECE
    Search for articles by this author
  • Author Footnotes
    # Nikolaos Kontopodis and Konstantinos Tzirakis equally contributed to this work and share 1st authorship.
Published:December 23, 2021DOI:https://doi.org/10.1016/j.avsg.2021.12.014

      Background

      It is accepted that surgically placed bifurcated aortic grafts should be shaped as a short proximal main tube with two long distal limbs. We aim to investigate the hemodynamic effect of different main body lengths in bifurcated aortic grafts using 3D computer models.

      Methods

      Five different idealized models are generated to represent an aorto-bifemoral graft. Distance from renal to femoral arteries is set at 25cm and distance between the femoral arteries is set at 14cm. Values of the main body length taken into account to build the idealized models are 3cm, 6cm, 9cm, 12cm and 15cm. Blood flow resistance, Time Average Wall Shear Stress (TAWSS), Oscillatory Shear Index (OSI) and Relative Residence Time (RRT) are estimated using the constructed 3D models.

      Results

      The total resistance decreased monotonically by as far as 40% as the main body length increased. Appropriate hemodynamic simulations show a maximum TAWSS decrease and a corresponding maximum OSI and RRT increase with elongated main body configurations, indicating a hemodynamic benefit of the “Short” main body configuration. Nevertheless, the differences in these later variables are small, affecting a limited portion of the geometries.

      Conclusion

      A long main body of a bifurcated aortic graft results in significantly reduced total resistance in idealized models designed to represent an aorto–bifemoral surgical graft, while the differences observed in TAWSS, OSI and RRT between models are small.
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