A probabilistic and anisotropic failure metric for ascending thoracic aortic aneurysm risk assessment

Minliang Liu, Liang Liang, Qing Zou, Yasmeen Ismail, Xiaoying Lou, Glen Iannucci, Edward P. Chen, Bradley G. Leshnower, John A. Elefteriades, Wei Sun

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

To noninvasively assess the risk of aneurysm rupture and dissection, an accurate material failure metric of the aortic wall is crucial. Previous studies used deterministic or isotropic failure metrics for the aortic wall. However, experimental studies have shown that aortic wall tensile strengths in circumferential and axial directions are significantly different (i.e., anisotropic) and vary greatly among patients. In this study, we developed a new probabilistic and anisotropic material failure metric for rupture risk assessment of ascending thoracic aortic aneurysm (ATAA). We performed uniaxial tensile failure tests using aortic tissue samples of 84 ATAA patients, from which a joint probability distribution of the anisotropic wall strengths was obtained. Subsequently, we derived an anisotropic failure probability (FP) metric based on the Tsai-Hill (TH) failure criterion. The novel FP metric incorporates uncertainty and anisotropy of failure properties. To compare the FP metric with traditional deterministic and isotropic metrics, we numerically estimated “baseline” risks of additional 41 ATAA patients using matching CT images and tissue testing data. We presented different risk assessment methods (e.g., with and without patient-specific hyperelastic properties) and compared them using receiver operating characteristic (ROC) curves. The results demonstrated that: (1) the probabilistic FP metric outperforms the deterministic TH metric and the isotropic maximum principal stress; (2) patient-specific hyperelastic properties can help to improve the performance of probabilistic FP metric in ATAA risk assessment. The proposed probabilistic modeling framework may be adopted for other types of materials.

Original languageEnglish (US)
Article number104539
JournalJournal of the Mechanics and Physics of Solids
Volume155
DOIs
StatePublished - Oct 2021

Keywords

  • Anisotropic
  • Aortic wall
  • Failure
  • Probabilistic
  • Risk assessment

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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