Publication detail

poroelastic model of intraluminal thrombus in FEA of aortic aneurysm

POLZER, S. BURŠA, J.

Original Title

poroelastic model of intraluminal thrombus in FEA of aortic aneurysm

English Title

poroelastic model of intraluminal thrombus in FEA of aortic aneurysm

Type

conference paper

Language

en

Original Abstract

The influence of the intraluminal thrombus (ILT) on the biomechanics of the abdominal aortic aneurysm (AAA) has been investigated for several years both numerically and experimentally. The FE analyses published till now simplified the material of the ILT as a homogenous continuum, but there is a contradiction between experiments and FE results. Therefore we use a poroelastic constitutive model for ILT. Poroelastic behaviour of the used finite element is based on the Biot theory of consolidation, the model consists of fluid and solid parts. By using idealized AAA models, we showed that the pres-sure decrease through the ILT is small for an 18mm thick ILT. Therefore approx. 90% of the blood pressure is acting on the inner AAA wall surface. These results agree very well with all experimental results, which show either slight or no pressure reduction. The wall stresses calculated by our approach are almost the same as those obtained by using the homogenous material model for ILT. Remarkably the model with poroelastic thrombus loaded by the blood pressure on the luminal surface of the ILT gives the same results as the model with homogeneous thrombus loaded on the inner surface of the AAA wall. These results support the theory that the stress reduction by ILT is caused by the adherent fibers, which serve as load bearing ropes stretched between different points on the arterial wall and consequently reduce the wall stress although the pressure is allowed to pene-trate through without a substantial reduction

English abstract

The influence of the intraluminal thrombus (ILT) on the biomechanics of the abdominal aortic aneurysm (AAA) has been investigated for several years both numerically and experimentally. The FE analyses published till now simplified the material of the ILT as a homogenous continuum, but there is a contradiction between experiments and FE results. Therefore we use a poroelastic constitutive model for ILT. Poroelastic behaviour of the used finite element is based on the Biot theory of consolidation, the model consists of fluid and solid parts. By using idealized AAA models, we showed that the pres-sure decrease through the ILT is small for an 18mm thick ILT. Therefore approx. 90% of the blood pressure is acting on the inner AAA wall surface. These results agree very well with all experimental results, which show either slight or no pressure reduction. The wall stresses calculated by our approach are almost the same as those obtained by using the homogenous material model for ILT. Remarkably the model with poroelastic thrombus loaded by the blood pressure on the luminal surface of the ILT gives the same results as the model with homogeneous thrombus loaded on the inner surface of the AAA wall. These results support the theory that the stress reduction by ILT is caused by the adherent fibers, which serve as load bearing ropes stretched between different points on the arterial wall and consequently reduce the wall stress although the pressure is allowed to pene-trate through without a substantial reduction

Keywords

Abdominal aortic aneurysm, intraluminal thrombus, poroelasticity, finite element model

RIV year

2010

Released

01.07.2010

Publisher

springer

Location

singapore

ISBN

978-3-642-14514-8

Book

6th world congress of biomechanics

Pages from

763

Pages to

767

Pages count

4

Documents

BibTex


@inproceedings{BUT35633,
  author="Stanislav {Polzer} and Jiří {Burša}",
  title="poroelastic model of intraluminal thrombus in FEA of aortic aneurysm",
  annote="The influence of the intraluminal thrombus (ILT) on the biomechanics of the abdominal aortic aneurysm (AAA) has been investigated for several years both numerically and experimentally. The FE analyses published till now simplified the material of the ILT as a homogenous continuum, but there is a contradiction between experiments and FE results. Therefore we use a poroelastic constitutive model for ILT. Poroelastic behaviour of the used finite element is based on the Biot theory of consolidation, the model consists of fluid and solid parts. 
By using idealized AAA models, we showed that the pres-sure decrease through the ILT is small for an 18mm thick ILT. Therefore approx. 90% of the blood pressure is acting on the inner AAA wall surface. These results agree very well with all experimental results, which show either slight or no pressure reduction. The wall stresses calculated by our approach are almost the same as those obtained by using the homogenous material model for ILT. 
Remarkably the model with poroelastic thrombus loaded by the blood pressure on the luminal surface of the ILT gives the same results as the model with homogeneous thrombus loaded on the inner surface of the AAA wall. These results support the theory that the stress reduction by ILT is caused by the adherent fibers, which serve as load bearing ropes stretched between different points on the arterial wall and consequently reduce the wall stress although the pressure is allowed to pene-trate through without a substantial reduction",
  address="springer",
  booktitle="6th world congress of biomechanics",
  chapter="35633",
  howpublished="electronic, physical medium",
  institution="springer",
  year="2010",
  month="july",
  pages="763--767",
  publisher="springer",
  type="conference paper"
}