Transitional flow at the venous anastomosis of an arteriovenous graft: Potential activation of the ERK1/2 mechanotransduction pathway

Francis Loth, Paul F. Fischer, Nurullah Arslan, Christopher D. Bertram, Seung E. Lee, Thomas J. Royston, Wael E. Shaalan, Hisham S. Bassiouny

Research output: Contribution to journalArticlepeer-review


We present experimental and computational results that describe the level, distribution, and importance of velocity fluctuations within the venous anastomosis of an arteriovenous graft. The motivation of this work is to understand better the importance of biomechanical forces in the development of intimal hyperplasia within these grafts. Steady-flow in vitro studies (Re=1060 and 1820) were conducted within a graft model that represents the venous anastomosis to measure velocity by means of laser Doppler anemometry. Numerical simulations with the same geometry and flow conditions were conducted by employing the spectral element technique. As flow enters the vein from the graft, the velocity field exhibits flow separation and coherent structures (weak turbulence) that originate from the separation shear layer. We also report results of a porcine animal study in which the distribution and magnitude of vein-wall vibration on the venous anastomosis were measured at the time of graft construction. Preliminary molecular biology studies indicate elevated activity levels of the extracellular regulatory kinase ERK1/2, a mitogen-activated protein kinase involved in mechanotransduction, at regions of increased vein-wall vibration. These findings suggest a potential relationship between the associated turbulence-induced vein-wall vibration and the development of intimal hyperplasia in arteriovenous grafts. Further research is necessary, however, in order to determine if a correlation exists and to differentiate the vibration effect from that of flow related effects.

Original languageEnglish (US)
Pages (from-to)49-61
Number of pages13
JournalJournal of Biomechanical Engineering
Issue number1
StatePublished - Feb 2003
Externally publishedYes

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physiology (medical)


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