Shear accumulation as a means for evaluating risk of thromboembolic events in novel endovascular stent graft designs

J Vasc Surg. 2017 Jun;65(6):1813-1819. doi: 10.1016/j.jvs.2016.07.108. Epub 2016 Sep 29.

Abstract

Objective: This study proposes to establish a simulation-based technique for evaluating shear accumulation in stent grafts and to use the technique to assess the performance of a novel branched stent graft system.

Methods: Computational fluid dynamics models, with transient boundary conditions, particle injection, and rigid walls, simplifying assumptions were developed and used to evaluate the shear accumulation in various stent graft configurations with a healthy aorta as comparison.

Results: Shear streamlines are presented for the various configurations. Shear accumulation was also calculated for each configuration. The number of particles with shear accumulations >3.5 Pa-s for each configuration was compared with the shear accumulation values of commercially available mechanical aortic valves from the literature.

Conclusions: The stent graft configuration with the diaphragm does have particles with shear accumulation >3.5 Pa-s. However, the percentage of particles with shear accumulation above 3.5 Pa-s is less than the two commercially available mechanical aortic valves, and more surprisingly, is smaller than in the healthy aorta.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aorta, Thoracic / physiopathology
  • Aorta, Thoracic / surgery*
  • Blood Flow Velocity
  • Blood Vessel Prosthesis Implantation / adverse effects*
  • Blood Vessel Prosthesis Implantation / instrumentation*
  • Blood Vessel Prosthesis*
  • Computer Simulation
  • Endovascular Procedures / adverse effects*
  • Endovascular Procedures / instrumentation*
  • Humans
  • Hydrodynamics
  • Models, Cardiovascular
  • Prosthesis Design*
  • Pulsatile Flow
  • Regional Blood Flow
  • Risk Assessment
  • Risk Factors
  • Stents*
  • Stress, Mechanical
  • Thromboembolism / etiology*
  • Thromboembolism / physiopathology