Annals of Biomedical Engineering

, Volume 42, Issue 12, pp 2440–2450

The Biaxial Biomechanical Behavior of Abdominal Aortic Aneurysm Tissue

  • Siobhan A. O’Leary
  • Donagh A. Healey
  • Eamon G. Kavanagh
  • Michael T. Walsh
  • Tim M. McGloughlin
  • Barry J. Doyle
Article

Abstract

Rupture of the abdominal aortic aneurysm (AAA) occurs when the local wall stress exceeds the local wall strength. Knowledge of AAA wall mechanics plays a fundamental role in the development and advancement of AAA rupture risk assessment tools. Therefore, the aim of this study is to evaluate the biaxial mechanical properties of AAA tissue. Multiple biaxial test protocols were performed on AAA samples harvested from 28 patients undergoing open surgical repair. Both the Tangential Modulus (TM) and stretch ratio (λ) were recorded and compared in both the circumferential (ϴ) and longitudinal (L) directions at physiologically relevant stress levels, the influence of patient specific factors such as sex, age AAA diameter and status were examined. The biomechanical response was also fit to a hyperplastic material model. The AAA tissue was found to be anisotropic with a greater tendency to stiffen in the circumferential direction compared to the longitudinal direction. An anisotropic hyperelastic constitutive model represented the data well and the properties were not influenced by the investigated patient specific factors however, a future study utilizing a larger cohort of patients is warranted to confirm these findings. This work provides further insights on the biomechanical behavior of AAA and may be useful in the development of more reliable rupture risk assessment tools.

Keywords

Mechanical properties AAA Anisotropy 

Supplementary material

10439_2014_1106_MOESM1_ESM.docx (727 kb)
Supplementary material 1 (DOCX 728 kb)

Copyright information

© Biomedical Engineering Society 2014

Authors and Affiliations

  • Siobhan A. O’Leary
    • 1
  • Donagh A. Healey
    • 2
  • Eamon G. Kavanagh
    • 2
  • Michael T. Walsh
    • 1
  • Tim M. McGloughlin
    • 1
    • 3
  • Barry J. Doyle
    • 4
    • 5
  1. 1.Mechanical, Aeronautical and Biomedical Engineering Department, MSG-013-020, Centre for Applied Biomedical Engineering Research, Materials and Surfaces Science InstituteUniversity of LimerickLimerickIreland
  2. 2.Department of Vascular SurgeryUniversity HospitalLimerickIreland
  3. 3.Department of Biomedical EngineeringKhalifa University of Science, Technology & Research (KUSTAR)Abu DhabiUAE
  4. 4.Vascular Engineering, Intelligent Systems for Medicine Laboratory, School of Mechanical and Chemical EngineeringThe University of Western AustraliaPerthAustralia
  5. 5.Centre for Cardiovascular ScienceThe University of EdinburghEdinburghUK

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