Class 13: Duplex Imaging of UEA & Hemodialysis Grafts Flashcards
what are the normal waveforms for the upper extremity arteries?
triphasic or biphasic. may be monophasic if arm has been heated or exercised
at the stenosis in the UE, you can expect to see (high/low) velocity
high velocity
what is hemodialysis?
a treatment used in renal failure
what is a dialyzer?
machine used during hemodialysis that removes waste products from blood through a filter – acts like the kidneys
how often is hemodialysis treatment?
typically 3x/week for 3-5 hours
what is a fistula?
abnormal connection bw artery & vein
what is an access graft?
a synthetic material placed between artery & veinn
what is an access graft used for?
hemodialysis puncture
what is another name for an AV fistula?
brescia-cimino
what is the most recommended type of hemodialysis graft?
AV fistula
why is the AV fistula the most recommended type of hemodialysis graft?
it provides long-term patency with low complication rates
which arteries & veins does an AV fistula connect?
radial artery to cephalic vein
or
ulnar artery to basilic vein
what are the other types of grafts made from PTFE?
- straight grafts
- looped grafts
what is another name for PTFE?
gortex
what does PTFE stand for?
polytetrafluoroethylene
what artery & vein does the forearm straight graft connect?
radial artery to median antecubital v. or basilic v.
what artery & vein does the upper arm reverse straight graft connect?
brachial a. to basilic v.
what does the forearm looped graft connect?
brachial artery to cephalic v./ median cubital v./basilic v.
what does the upper arm looped graft connect?
brachial a. to axillary v.
what does the looped graft in the LE connect?
SFA to GSV
what 5 areas do we need to evaluate for grafts?
- inflow artery
- PROX anastomotic area
- within graft
- DIST anastomotic area
- outflow vein
what are you looking for when evaluating grafts?
- aneurysms
- leaks at puncture sites
- peri-graft fluid collection
- other abnormalities
6 graft complications
- thrombosis/occlusion
- stenosis
- arterial steal syndrome
- venous hypertension
- aneurysm
- pseudoaneurysm
PSV & EDV velocity & resistance within the graft?
both slightly elevated velocities with low resistance
a low PSV within a graft may be due to ____
arterial inflow problems
most common sites for stenosis with grafts?
- venous anastomosis
- outflow vein
what is arterial steal syndrome?
flow is stolen from the distal part of graft
what are 3 S&S of arterial steal syndrome?
- pain with exertion of affected UE
- pallor of affected UE
- skin is cool distal to the graft
what size is problematic for a pseudoaneurysm for the UE?
> 1 cm
what can cause a pseudoaneurysm in the UE?
graft disintegration, problems at the site of graft anastomosis
what causes venous hypertension?
- retrograde venous flow
- forearm loop graft with venous stenosis
2 S&S with a patient with venous hypertension?
- hand swelling
- venous stasis
