# FIGURES

![](media/image1.wmf)

Figure 1. Geometry and nomenclature of the venous anastomosis A-V graft
model.

![](media/image2.png){width="5.625196850393701in"
height="1.75in"}![](media/image3.wmf){width="5.718897637795275in"
height="1.7602362204724409in"}![](media/image4.png){width="5.6200787401574805in"
height="2.0401574803149605in"}

Figure 2. 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.

Figure 3. Computerized tomography images of the AV graft physical model
used to measure the 3D lumen geometry.

![](media/image15.png){width="1.20625in" height="3.375in"}

Figure 4. 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).

![](media/image20.wmf){width="1.8263888888888888in"
height="1.9694444444444446in"} ![](media/image21.wmf)

**Figure 5.** Sketch of the aorto-external iliac vein graft and the
anastomotic geometry with defined regions for biomechanical and biologic
studies.

![](media/image22.wmf){width="5.552777777777778in"
height="8.124305555555555in"}

Figure 6. LDA velocity measurements at Re = 1060 in the plane of the
bifurcation: (a) mean velocity vectors, (b) *u*‑component turbulent
fluctuations, *u*~rms~, (c) v‑component turbulent fluctuations,
*v*~rms~, (d) Reynolds stress, *ρu*′*v*′.

![](media/image23.wmf){width="5.5125in" height="7.884722222222222in"}

Figure 7. LDA velocity measurements at Re = 1820 in the plane of the
bifurcation: (a) mean velocity vectors, (b) *u*‑component turbulent
fluctuations, *u*~rms~, (c) v‑component turbulent fluctuations,
*v*~rms~, (d) Reynolds stress, *ρu*′*v*′.

![](media/image24.wmf){width="5.013888888888889in"
height="1.4034722222222222in"}

![](media/image24.wmf){width="5.0256944444444445in"
height="0.7229166666666667in"}

![](media/image25.wmf){width="2.467361111111111in"
height="0.8333333333333334in"}![](media/image25.wmf){width="2.339583333333333in"
height="0.8333333333333334in"}

Figure 8. LDA measurements of mean velocity for velocity component
parallel to the plane of the bifurcation and perpendicular to the floor
of the graft (*v*~mean~) at different axial locations. (a) secondary
flow within the anastomosis at Re = 1060, (b) secondary flow within and
just upstream of the PVS at Re = 1060, (c) secondary flow within and
just upstream of the PVS at Re = 1820. Note that these are 1D 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.

![](media/image28.wmf){width="5.263888888888889in"
height="1.6895833333333334in"}

![](media/image29.wmf){width="3.6958333333333333in"
height="1.4069444444444446in"}

![](media/image30.wmf){width="3.7597222222222224in"
height="1.4368055555555554in"}

![](media/image31.wmf){width="3.727777777777778in"
height="1.5333333333333334in"}

Figure 9. 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, *u*~rms~, (d) *v*‑component
turbulent fluctuations, *v*~rms~.

![](media/image32.png){width="6.625in" height="1.5625in"}

![](media/image33.png){width="6.645833333333333in"
height="1.6145833333333333in"}

**Figure 10.** CFD simulation of the vorticity distribution at Re = 1060
(top) and 1820 (bottom) in the plane of the bifurcation.

![](media/image34.png){width="2.7375in" height="2.792361111111111in"}
![](media/image35.png){width="3.79375in" height="2.80625in"}

**Figure 11.** Coherent structures (vortices) identified by using the
λ~2~ criterion of Jong and Hussain (75): left - full view, right - zoom
view. Color represents the instantaneous 3D-pressure distribution at
this time point; .

![](media/image36.wmf){width="3.2395833333333335in"
height="2.435416666666667in"}
![](media/image37.wmf){width="3.223611111111111in"
height="2.4229166666666666in"}

![](media/image38.png){width="2.529861111111111in"
height="1.9069444444444446in"}

**Figure 12.** Time-average WSS computed from CFD simulations (a) axial
distribution at Re=1060, (b) axial distribution 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).

![](media/image40.png){width="2.1631944444444446in"
height="2.404166666666667in"}![](media/image41.png){width="2.629861111111111in"
height="2.401388888888889in"}

**Figure 13.** Instantaneous view from the CFD results of the WSS
vectors on the lumen surface and zoom view in which the complex pattern
of WSS magnitude and direction is evident.

![](media/image42.wmf){width="5.18125in" height="3.8868055555555556in"}

**Figure 14.** Vein-wall vibration velocity measured directly on the
vein during surgery. Note the greater vibration at region B compared
with regions A and C. Regions of anastomosis are shown in Figure 5.

![](media/image43.wmf){width="3.7944444444444443in"
height="2.6798611111111112in"}

**Figure 15.** 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.

![](media/image44.png){width="6.941666666666666in" height="1.90625in"}

**Figure 16.** Immunolocalization of ERK1/2 at four hours in (a) normal
vein, (b) region of reduced vein wall vibration, (c) region of elevated
vein wall vibration. ERK1/2 immunostaining is represented by the 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).

![](media/image45.png){width="3.875in" height="2.86875in"}

**Figure 17.** Immunolocalization of ERK1/2 at 4 weeks in (a) region of
elevated vein-wall vibration and (b) reduced vein wall vibration.
Densitometric analysis of immunostaining intensity for (a) and (b) is
shown in (c) and (d), respectively. ERK1/2 immunostaining is
predominately localized in the intimal region and is 2.5 fold greater in
(a) compared with (b). Blue arrows indicated intima media thickness (40X
magnification).

![](media/image46.png){width="5.966666666666667in" height="1.7375in"}

**Figure 18.** Immunostaining for (a) ERK1/2, (b) T-lymphocytes, and (c)
macrophages in region of elevated vein wall vibration at 4 weeks in
immediately adjacent cross sections (5 μm apart). Note the lack of
co-localization between ERK1/2 and the inflammatory cells.