J 2018

Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms

MAN, V., S. POLZER, T.C. GASSER, Tomáš NOVOTNÝ, J. BURSA et. al.

Basic information

Original name

Impact of isotropic constitutive descriptions on the predicted peak wall stress in abdominal aortic aneurysms

Authors

MAN, V. (203 Czech Republic, guarantor), S. POLZER (203 Czech Republic), T.C. GASSER (752 Sweden), Tomáš NOVOTNÝ (203 Czech Republic, belonging to the institution) and J. BURSA (203 Czech Republic)

Edition

MEDICAL ENGINEERING & PHYSICS, OXFORD, ELSEVIER SCI LTD, 2018, 1350-4533

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

30212 Surgery

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 1.785

RIV identification code

RIV/00216224:14110/18:00102966

Organization unit

Faculty of Medicine

UT WoS

000429510600005

Keywords in English

Abdominal aortic aneurysm; Wall stress; Non-linear material model

Tags

International impact, Reviewed
Změněno: 10/2/2019 14:40, Soňa Böhmová

Abstract

V originále

Biomechanics-based assessment of Abdominal Aortic Aneurysm (AAA) rupture risk has gained considerable scientific and clinical momentum. However, computation of peak wall stress (PWS) using state-ofthe-art finite element models is time demanding. This study investigates which features of the constitutive description of AAA wall are decisive for achieving acceptable stress predictions in it. Influence of five different isotropic constitutive descriptions of AAA wall is tested; models reflect realistic non-linear, artificially stiff non-linear, or artificially stiff pseudo-linear constitutive descriptions of AAA wall. Influence of the AAA wall model is tested on idealized (n = 4) and patient-specific (n = 16) AAA geometries. Wall stress computations consider a (hypothetical) load-free configuration and include residual stresses homogenizing the stresses across the wall. Wall stress differences amongst the different descriptions were statistically analyzed. When the qualitatively similar non-linear response of the AAA wall with low initial stiffness and subsequent strain stiffening was taken into consideration, wall stress (and PWS) predictions did not change significantly. Keeping this non-linear feature when using an artificially stiff wall can save up to 30% of the computational time, without significant change in PWS. In contrast, a stiff pseudo-linear elastic model may underestimate the PWS and is not reliable for AAA wall stress computations. (C) 2018 IPEM. Published by Elsevier Ltd. All rights reserved.