Diagnostic ultrasound ( PDFDrive )

CHAPTER 27 Peripheral Vessels 1001
A
B
C
FIG. 27.57 Thigh Graft Preoperative Mapping. (A) Heavy arterial
calciication is seen in the common femoral artery (CFA; *) with
normal common femoral vein compression (compression not shown).
(B) Longitudinal view of the mid supericial femoral artery (SFA) also
shows heavy arterial calciication. (C) Spectral Doppler waveform of
the mid SFA does not have a normal triphasic or biphasic waveform.
These arteries may be too heavily calciied to sew into, and would
likely prompt further evaluation of the patient’s arterial inlow to assess
whether thigh graft placement is possible in this patient.
color and spectral Doppler in the longitudinal plane to document
normal low-resistance low (Fig. 27.58). Measurements of PSV
and EDV can be obtained in the feeding artery, and at least at
the anastomosis(es). here may be multiple anastomoses in the
case of a grat. he draining vein of the AVF or grat is inspected
for wall thickening, stenosis, and thrombosis along its entire
length. 143
If a stenosis is seen, the highest PSV either within the stenosis
or in the jet downstream from the stenosis is measured, using
angle correction parallel to the jet if diferent from the angle with
the posterior vascular wall, keeping the angle to 60 degrees or
less. he PSV 2 cm upstream to the stenosis is measured, and
a PSV ratio of the PSV at the stenosis divided by the upstream
PSV is calculated. A longitudinal gray-scale image is obtained
to document any intraluminal thrombus identiied within a
draining vein or grat. Duplex Doppler should be performed to
conirm absence of low, with use of the more sensitive power
Doppler as needed. Description of artery and vein location
with regard to the AVF and grat can be diicult. Terminology
including cranial and caudal location with regard to a
particular anastomosis, and upstream or downstream position,
may be more useful than the conventional proximal and distal
terminology.
Arteriovenous Fistula
he feeding artery luminal diameter is measured. Spectral and
color Doppler evaluations of the feeding artery are performed
to evaluate for arterial stenosis or occlusion. he anastomosis is
assessed for visible narrowing with subsequent spectral and color
Doppler evaluation. he AVF draining vein diameter is evaluated
at several levels from the anastomosis to 15 cm cranial to the
anastomosis. he intraluminal draining vein diameter and the
depth of the vein from the skin surface are measured at several
points cranial to the arteriovenous anastomosis. Access challenges
may result with a depth greater than 5 to 6 mm and require
supericialization. 131,150 he draining vein is interrogated for
accessory branches (Fig. 27.59). Intraluminal diameter and
distance from the anastomosis are recorded for each identiied
accessory vein within 10 to 15 cm of the anastomotic site. he
low volume rate measurements are obtained within the midportion
of the draining vein of an AVF, typically at 10 cm cranial
to the anastomosis. Optimal low volume measurement is obtained