A simulation framework for estimating wall stress distribution of abdominal aortic aneurysm

Annu Int Conf IEEE Eng Med Biol Soc. 2011:2011:900-3. doi: 10.1109/IEMBS.2011.6090201.

Abstract

Abdominal aortic aneurysm (AAA) rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue. In endovascular aneurysm repair, a stent-graft in a catheter is released at the aneurysm site to form a new blood vessel and protect the weakened AAA wall from the pulsatile pressure and, hence, possible rupture. In this paper, we propose a framework to estimate the wall stress distribution of non-stented/stented AAA based on fluid-structure interaction, which is utilized in a surgical simulation system (IRAS). The 3D geometric model of AAA is reconstructed from computed tomography angiographic (CTA) images. Based on our experiments, a combined logarithm and polynomial strain energy equation is applied to model the elastic properties of arterial wall. The blood flow is modeled as laminar, incompressible, and non-Newtonian flow by applying Navier-Stokes equation. The obtained pressure of blood flow is applied as load on the AAA meshes with and without stent-graft and the wall stress distribution is calculated by fluid-structure interaction (FSI) solver equipped in ANSYS. Experiments demonstrate that our analytical results are consistent with clinical observations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aortic Aneurysm, Abdominal / physiopathology*
  • Aortic Aneurysm, Abdominal / surgery*
  • Blood Flow Velocity
  • Blood Pressure
  • Blood Vessel Prosthesis*
  • Computer Simulation
  • Elastic Modulus
  • Humans
  • Models, Cardiovascular*
  • Shear Strength
  • Stents*
  • Stress, Mechanical
  • Tomography, X-Ray Computed