Annals of Biomedical Engineering

, Volume 45, Issue 8, pp 1908–1916 | Cite as

The Association Between Geometry and Wall Stress in Emergently Repaired Abdominal Aortic Aneurysms

  • Sathyajeeth S. Chauhan
  • Carlos A. Gutierrez
  • Mirunalini Thirugnanasambandam
  • Victor De Oliveira
  • Satish C. Muluk
  • Mark K. Eskandari
  • Ender A. Finol


Abdominal aortic aneurysm (AAA) is a prevalent cardiovascular disease characterized by the focal dilation of the aorta, which supplies blood to all the organs and tissues in the systemic circulation. With the AAA increasing in diameter over time, the risk of aneurysm rupture is generally associated with the size of the aneurysm. If diagnosed on time, intervention is recommended to prevent AAA rupture. The criterion to decide on surgical intervention is determined by measuring the maximum diameter of the aneurysm relative to the critical value of 5.5 cm. However, a more reliable approach could be based on understanding the biomechanical behavior of the aneurysmal wall. In addition, geometric features that are proven to be significant predictors of the AAA wall mechanics could be used as surrogates of the AAA biomechanical behavior and, subsequently, of the aneurysm’s risk of rupture. The aim of this work is to identify those geometric indices that have a high correlation with AAA wall stress in the population of patients who received an emergent repair of their aneurysm. In-house segmentation and meshing algorithms were used to model 75 AAAs followed by estimation of the spatially distributed wall stress by performing finite element analysis. Fifty-two shape and size geometric indices were calculated for the same models using MATLAB scripting. Hypotheses testing were carried out to identify the indices significantly correlated with wall stress by constructing a Pearson’s correlation coefficient matrix. The analyses revealed that 12 indices displayed high correlation with the wall stress, amongst which wall thickness and curvature-based indices exhibited the highest correlations. Stepwise regression analysis of these correlated indices indicated that wall stress can be predicted by the following four indices with an accuracy of 76%: maximum aneurysm diameter, aneurysm sac length, average wall thickness at the maximum diameter cross-section, and the median of the wall thickness variance. The primary outcome of this work emphasizes the use of global measures of size and wall thickness as geometric surrogates of wall stress for emergently repaired AAAs.


Finite element modeling Arterial biomechanics Geometric modeling 



The authors have no conflicts of interest to disclose and would like to acknowledge research funding from National Institutes of Health Award R01HL121293 and American Heart Association Award 15PRE25700288. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the American Heart Association.

Supplementary material

10439_2017_1837_MOESM1_ESM.pdf (700 kb)
Supplementary material 1 (PDF 700 kb)


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Copyright information

© Biomedical Engineering Society 2017

Authors and Affiliations

  • Sathyajeeth S. Chauhan
    • 1
  • Carlos A. Gutierrez
    • 1
  • Mirunalini Thirugnanasambandam
    • 1
  • Victor De Oliveira
    • 2
  • Satish C. Muluk
    • 3
  • Mark K. Eskandari
    • 4
  • Ender A. Finol
    • 1
    • 5
  1. 1.UTSA/UTHSCSA Joint Graduate Program in Biomedical EngineeringUniversity of Texas at San AntonioSan AntonioUSA
  2. 2.Department of Management Science and StatisticsUniversity of Texas at San AntonioSan AntonioUSA
  3. 3.Department of Thoracic & Cardiovascular Surgery, Allegheny General HospitalAllegheny Health NetworkPittsburghUSA
  4. 4.Division of Vascular Surgery and Department of Radiology, Northwestern Memorial Hospital, Feinberg School of MedicineNorthwestern UniversityChicagoUSA
  5. 5.Department of Mechanical EngineeringUniversity of Texas at San AntonioSan AntonioUSA

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