0
TECHNICAL PAPERS: Fluids/Heat/Transport

Transitional Flow at the Venous Anastomosis of an Arteriovenous Graft: Potential Activation of the ERK1/2 Mechanotransduction Pathway

[+] Author and Article Information
Francis Loth

Department of Mechanical Engineering and Industrial Engineering, The University of Illinois at Chicago, Chicago, Illinois, 60607e-mail: floth@uic.edu

Paul F. Fischer

Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, 60439e-mail: fischer@mcs.anl.gov

Nurullah Arslan

Department of Industrial Engineering, Fatih University, Istanbul, Turkeye-mail: narslan@fatih.edu.tr

Christopher D. Bertram

Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia, 2033e-mail: c.bertram@unsw.edu.au

Seung E. Lee

Department of Mechanical Engineering, The University of Illinois at Chicago, Chicago, Illinois, 60607e-mail: slee48@uic.edu

Thomas J. Royston

Department of Mechanical Engineering, The University of Illinois at Chicago, Chicago, Illinois, 60607e-mail: troyston@uic.edu

Wael E. Shaalan

Department of Surgery, The University of Chicago, Chicago, Illinois, 60637e-mail: wshaalan@surgery.bsd.uchicago.edu

Hisham S. Bassiouny

Department of Surgery, The University of Chicago, Chicago, Illinois, 60637e-mail: hbassiou@surgery.bsd.uchicago.edu

J Biomech Eng 125(1), 49-61 (Feb 14, 2003) (13 pages) doi:10.1115/1.1537737 History: Received September 01, 2001; Revised August 01, 2002; Online February 14, 2003
Copyright © 2003 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Geometry and nomenclature of the venous anastomosis A-V graft model
Grahic Jump Location
Color Doppler ultrasound images on a dialysis patient’s graft-to-vein junction (venous anastomosis). Velocity traces are shown for measurements taken near the centerline of the (a) PTFE graft, (b) proximal venous segment (PVS), and (c) distal venous segment (DVS). Note the large magnitude of velocities in the graft and PVS with significant spectral broadening in the PVS trace.
Grahic Jump Location
Computerized tomography images of the AV graft physical model used to measure the 3D lumen geometry
Grahic Jump Location
Three curved tubes with two angled surfaces (a) are joined to create the 3-D bifurcation representing the arteriovenous geometry (b). This mesh is refined and extensions are added to produce the final mesh (c).
Grahic Jump Location
Sketch of the aorto-external iliac vein graft (LEFT) and the anastomotic geometry with defined regions for biomechanical and biologic studies (RIGHT)
Grahic Jump Location
LDA velocity measurements at Re=1060 in the plane of the bifurcation: (a) mean velocity vectors, (b) u-component turbulent fluctuations, urms, (c) v-component turbulent fluctuations, vrms, (d) Reynolds stress, ρuv
Grahic Jump Location
LDA velocity measurements at Re=1820 in the plane of the bifurcation: (a) mean velocity vectors, (b) u-component turbulent fluctuations, urms, (c) v-component turbulent fluctuations, vrms, (d) Reynolds stress, ρuv
Grahic Jump Location
LDA measurements of mean velocity for velocity component parallel to the plane of the bifurcation and perpendicular to the floor of the graft (vmean) at different axial locations. (a) secondary flow within the anastomosis at Re=1060, (b) secondary flow within and just downstream of the PVS at Re=1060, and (c) secondary flow within and just downstream of the PVS at Re=1820. Note that these are 1-D vectors of v-component amplitude; the other component in the cross-section plane, the w-component (flow normal to the bifurcation plane), was not measured.
Grahic Jump Location
CFD velocity results in the plane of the bifurcation: (a) mean velocity vectors at Re=1060, (b) mean velocity vectors at Re=1820, (c) u-component turbulent fluctuations, urms, (d) v-component turbulent fluctuations, vrms
Grahic Jump Location
CFD simulation of the instantaneous vorticity distribution at Re=1060 (top) and 1820 (bottom) in the plane of the bifurcation
Grahic Jump Location
Coherent structures (vortices) identified using the λ2 criterion of Jong and Hussain 47. Color represents the instantaneous 3D-pressure distribution. Left-full view, Right-detailed view downstream of toe.
Grahic Jump Location
Time average WSS computed from CFD simulations (a) axial distribution (θ=0°) at Re=1060, (b) axial distribution (θ=0°) at Re=1820, (c) axial and circumferential distribution at Re=1820. (Note: the spike in WSS at the toe of the graft is caused by the sharp angle of the flow model.)
Grahic Jump Location
Instantaneous view from the CFD results of the WSS vectors on the lumen surface (LEFT), zoom view in which the complex pattern of WSS magnitude and direction is evident (RIGHT)
Grahic Jump Location
Vein-wall vibration velocity measured directly on the vein during surgery. Note the greater vibration at region B compared to regions A and C. Regions of anastomosis are shown in Fig. 5.
Grahic Jump Location
MAP kinase assay (top panel) and Western blot assay (center and bottom panels) for ERK1/2 activity and phosphorylation from different regions (A and B) of anastomotic vein and normal control vein (NV). The bands of β-Actin indicate the loading conditions.
Grahic Jump Location
Immunolocalization of ERK1/2 at four hours in (a) normal vein, (b) region of reduced vein wall vibration (region A), (c) and region of elevated vein wall vibration (region B). ERK1/2 immunostaining is represented by dark brown color in the intima and media. Note the markedly increased ERK1/2 density in the intimal and media of vein wall with elevated vibration (c) relative to (a) and (b). Internal elastic lamina is indicated as IEL (40X magnification).
Grahic Jump Location
Immunolocalization of ERK1/2 at four weeks in (a) region of reduced vein wall vibration (region A) and (b) region of elevated vein-wall vibration (region B). Densitometric analysis of immunostaining intensity for (a) and (b) is shown in (c) and (d). ERK1/2 immunostaining is predominately localized in the intimal region and is 2.5 fold greater in (b) compared to (a). Magnification 40X.
Grahic Jump Location
Immunostaining for (a) ERK1/2, (b) T-lymphocytes and (c) macrophages in region of elevated vein wall vibration (region B) at 4 weeks in immediately adjacent cross sections (5 μ apart). Note the lack of co-localization between ERK1/2 and the inflammatory cells.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In