Ascending thoracic aortic aneurysm (ATAA) has been associated with diminished biomechanical strength and disruption in the collagen fiber microarchitecture. Additionally, the congenital bicuspid aortic valve (BAV) leads to a distinct extracellular matrix structure that may be related to ATAA development at an earlier age than degenerative aneurysms arising in patients with the morphological normal tricuspid aortic valve (TAV). The purpose of this study was to model the fiber-reinforced mechanical response of ATAA specimens from patients with either BAV or TAV. This was achieved by combining image-analysis derived parameters of collagen fiber dispersion and alignment with tensile testing data. Then, numerical simulations were performed to assess the role of anisotropic constitutive formulation on the wall stress distribution of aneurysmal aorta. Results indicate that both BAV ATAA and TAV ATAA have altered collagen fiber architecture in the medial plane of experimentally-dissected aortic tissues when compared to normal ascending aortic specimens. The study findings highlight that differences in the collagen fiber distribution mostly influences the resulting wall stress distribution rather than the peak stress. We conclude that fiber-reinforced constitutive modeling that takes into account the collagen fiber defect inherent to the aneurysmal ascending aorta is paramount for accurate finite element predictions and ultimately for biomechanical-based indicators to reliably distinguish the more from the less 'malignant' ATAAs.

Pasta, S., Phillippi, J., Tsamis, A., D'Amore, A., Raffa, G., Pilato, M., et al. (2016). Constitutive modeling of ascending thoracic aortic aneurysms using microstructural parameters. MEDICAL ENGINEERING & PHYSICS, 38(2), 121-130 [10.1016/j.medengphy.2015.11.001].

Constitutive modeling of ascending thoracic aortic aneurysms using microstructural parameters

PASTA, Salvatore
;
D'AMORE, Antonio;
2016-01-01

Abstract

Ascending thoracic aortic aneurysm (ATAA) has been associated with diminished biomechanical strength and disruption in the collagen fiber microarchitecture. Additionally, the congenital bicuspid aortic valve (BAV) leads to a distinct extracellular matrix structure that may be related to ATAA development at an earlier age than degenerative aneurysms arising in patients with the morphological normal tricuspid aortic valve (TAV). The purpose of this study was to model the fiber-reinforced mechanical response of ATAA specimens from patients with either BAV or TAV. This was achieved by combining image-analysis derived parameters of collagen fiber dispersion and alignment with tensile testing data. Then, numerical simulations were performed to assess the role of anisotropic constitutive formulation on the wall stress distribution of aneurysmal aorta. Results indicate that both BAV ATAA and TAV ATAA have altered collagen fiber architecture in the medial plane of experimentally-dissected aortic tissues when compared to normal ascending aortic specimens. The study findings highlight that differences in the collagen fiber distribution mostly influences the resulting wall stress distribution rather than the peak stress. We conclude that fiber-reinforced constitutive modeling that takes into account the collagen fiber defect inherent to the aneurysmal ascending aorta is paramount for accurate finite element predictions and ultimately for biomechanical-based indicators to reliably distinguish the more from the less 'malignant' ATAAs.
2016
Settore ING-IND/34 - Bioingegneria Industriale
Settore ING-IND/14 - Progettazione Meccanica E Costruzione Di Macchine
Pasta, S., Phillippi, J., Tsamis, A., D'Amore, A., Raffa, G., Pilato, M., et al. (2016). Constitutive modeling of ascending thoracic aortic aneurysms using microstructural parameters. MEDICAL ENGINEERING & PHYSICS, 38(2), 121-130 [10.1016/j.medengphy.2015.11.001].
File in questo prodotto:
File Dimensione Formato  
Constitutive.pdf

Solo gestori archvio

Tipologia: Versione Editoriale
Dimensione 2.72 MB
Formato Adobe PDF
2.72 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
nihms740555.pdf

accesso aperto

Descrizione: Author manuscript
Tipologia: Pre-print
Dimensione 1.69 MB
Formato Adobe PDF
1.69 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/222125
Citazioni
  • ???jsp.display-item.citation.pmc??? 12
  • Scopus 43
  • ???jsp.display-item.citation.isi??? 41
social impact