title: In vitro analysis of localized aneurysm rupture.
abstract: In this study, bulge inflation tests were used to characterize the failure response of 15 layers of human ascending thoracic aortic aneurysms (ATAA). Full field displacement data were collected during each of the mechanical tests using a digital image stereo-correlation (DIS-C) system. Using the collected displacement data, the local stress fields at burst were derived and the thickness evolution was estimated during the inflation tests. It was shown that rupture of the ATAA does not systematically occur at the location of maximum stress, but in a weakened zone of the tissue where the measured fields show strain localization and localized thinning of the wall. Our results are the first to show the existence of weakened zones in the aneurysmal tissue when rupture is imminent. An understanding these local rupture mechanics is necessary to improve clinical assessments of aneurysm rupture risk. Further studies must be performed to determine if these weakened zones can be detected in vivo using non-invasive techniques.
authors.affiliation: Center for Biomedical and Healthcare Engineering, Ecole Nationale Supérieure des Mines de Saint-Etienne, CIS-EMSE, CNRS:UMR5146, LCG, 158 Cours Fauriel, 42023 Saint Etienne, France. Electronic address: romo@emse.fr.
authors.forename: Aaron
authors.initials: A
authors.lastname: Romo
authors.affiliation: Center for Biomedical and Healthcare Engineering, Ecole Nationale Supérieure des Mines de Saint-Etienne, CIS-EMSE, CNRS:UMR5146, LCG, 158 Cours Fauriel, 42023 Saint Etienne, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Badel
authors.affiliation: Hôpital Nord, Cardiovascular Surgery Service, CHU de Saint Etienne, F-42055 Saint-Etienne Cedex 2, France.
authors.forename: Ambroise
authors.initials: A
authors.lastname: Duprey
authors.affiliation: Hôpital Nord, Cardiovascular Surgery Service, CHU de Saint Etienne, F-42055 Saint-Etienne Cedex 2, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Favre
authors.affiliation: Center for Biomedical and Healthcare Engineering, Ecole Nationale Supérieure des Mines de Saint-Etienne, CIS-EMSE, CNRS:UMR5146, LCG, 158 Cours Fauriel, 42023 Saint Etienne, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Avril
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017545:Aortic Aneurysm, Thoracic / Q000503:physiopathology*; D001019:Aortic Rupture / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D013314:Stress, Mechanical
keywords: Aneurysm; Human aorta; Inflation test; Rupture; Ultimate stress