Computational fluid dynamics analysis to determine shear stresses and rates in a centrifugal left ventricular assist device.

Published

Journal Article

Axial flow left ventricular assist devices (LVADs) are a significant improvement in mechanical circulatory support. However, patients with these devices experience degradation of large von Willebrand factor (vWF) multimers, which is associated with bleeding and may be caused by high shear stresses within the LVAD. In this study, we used computational fluid mechanics to determine the wall shear stresses, shear rates, and residence times in a centrifugal LVAD and assess the impact on these variables caused by changing impeller speed and changing from a shrouded to a semi-open impeller. In both LVAD types, shear rates were well over 10,000/s in several regions. This is high enough to degrade vWF, but it is unclear if residence times, which were below 5ms in high-shear regions, are long enough to allow vWF cleavage. Additionally, wall shear stresses were below the threshold stress of 10Pa only in the outlet tube so it is feasible to endothelialize this region to enhance its biocompatibility.

Full Text

Duke Authors

Cited Authors

  • Selgrade, BP; Truskey, GA

Published Date

  • April 2012

Published In

Volume / Issue

  • 36 / 4

Start / End Page

  • E89 - E96

PubMed ID

  • 22360826

Pubmed Central ID

  • 22360826

Electronic International Standard Serial Number (EISSN)

  • 1525-1594

International Standard Serial Number (ISSN)

  • 0160-564X

Digital Object Identifier (DOI)

  • 10.1111/j.1525-1594.2011.01416.x

Language

  • eng