LE Extremilty Arterial Angioplasty and Grafts Flashcards
what are some conservative medical treatments for arterial dx (5)? how about some interventional surical treatments? (2)
Conservative/Medical treatment
Cessation of smoking – decrease vasoconstriction
Regular exercise-promote collaterals
Lowering cholesterol and LDL
Medications options: Trental, Pletal – reduce blood viscosity, inhibits platelet aggregtion
Interventional/Surgical treatment
Bypass grafts
Angioplasty and stents
what types of bypass are there
Synthetic: PTFE (more common) and Dacron
Organic
angioplasty
stent with a balloon to open up the vessel
what is this?
ptfe graft
what type of aorto-femoal grafts are there? (3)
what types of organic bypass grafts are there? (4)
Reversed
In situ
Composite
Great or Lesser saphenous, basilic,cephalic)
what type of graft
Uses greater saphenous vein (GSV) in native bed
Valves leaflets are excised
Perforators / tributaries are ligated
Proximal and distal ends are anastomosed to artery
Femoral - distal graft In situ Vein Graft
what is this?
Valvulatome - cuts out valves in vessels
what type of graft is this
in situ vein graft (rt) due to occluded sfa (lt)
what type of graft
In situ
femoro-popliteal
graft
what type of graft
In situ fem-tibial graft
what type of graft has these procedures?
GSV harvested
Perforating veins and tributaries are ligated and cut
Vein reversed and implanted as bypass
Valves are not excised
Small diameter proximally, large diameter distally is advantageous
Reverse vein graft
how often are grafts surveyed after complete?
Evaluation immediately post op
1 week post op
6 week post op
Every 3 months x 2 years
Every 6 months for life
a few days after a graft patients experience _______. describe the waveform. how long before this resolves?
Acute Hyperperfusion
1-2 days post op.
Revascularization hyperemia because patient still vasodilated
High peak systolic
High diastolic (low resistance)
Resolves in 2-3 weeks
what type of graft failures might you expect w/ a synthetic graft?
1-2 years out = technical error or fibrointimal lesions at anastomosis
2-5 years out = progression of atherosclerotic disease of native vessels proximal or distal to graft with chronic thrombus
5-10 years out = pseudoaneurysms (esp aorto-femoral) secondary to infections
what type of graft failure
0-2 months = technical error such as poor anastomosis, AVF from perforators, poorly lysed valves
1-2 years = fibro-intimal lesions at anastomosis or at valves sinuses
>2 years = progression of atherosclerotic disease
autogenous
what can slow flow in a graft (failure) be due to?
Decreased inflow:
Arterial disease proximal to graft
Stenosis at proximal anastomosis
Decresed outflow:
Arterial disease distal to graft
Stenosis at distal anastomosis
Stenosis within the graft causing slow flow distal to the stenotic area AVF of the graft decreasing flow distally
what % is the stenosis rate within 1 year of a graft?
if graft occludes, ______% patency rate after thrombectomy
_____% of graft stenoses are ASX, due to limited ambulation - limb salvage
20-30 %
20-50
60
the following steps are _________
Identify graft type
Perform ABI – if applicable, also could do toe PPG and metatarsal
Map graft and record spectral waveforms
Prox to graft
Prox anastomosis site
Mid graft
Distal anastomosis site
Distal to graft
Measure PSV and EDV
Evaluate waveform morphology – triphasic, high resistance, acceleration, etc.
Bypass graft surveillance
what is the avg graft flow velocity?
what do you look for when evaluating a graft?
wall irregularity
partially excised valve leaflets
A-V in non-ligated perforators (insitu only)
Aneurysm
P-aneurysm
what type of testing can you do over a graft?
a ____ drop in ABI suggests graft stenosis
_______ is more sensitve than ABI for stenosis
PVR, not segmentals
0.15
duplex
50% stenosis
Peak Velocities > ______
Velocity ratio > ____
Post stenotic turbulence
>75% stenosis
Peak vel > ___
Velocity ratio >____
Post stenotic turbulence
Distal flow of <____ cm/s associated with high rate of graft failure
Color flow shows _____ and __________
Be aware of increased velocities large vein graft entering smaller artery as with reversed.
Peak Velocities > 150cm/s
Velocity ratio > 2.0
Peak vel > 250 cm/s
Velocity ratio > 3.0
45
aliasing, turbulence
what velocity is considered normal in a vein graft?
What is the threshold for graft revision?
> 300 cm/s
VR > 3.5
low velocity < 40-45 cm/s
ABI
what type of graft stenosis is this?
reverse vein graft stenosis
what is this?
vein graft aneurysm
what is happening here?
how can you tell?
pseuodoaneurysm
Most commonly at anastomosis site
Perigraft fluid collection with swirling flow
To and Fro
Ying-Yang with color
what will the waveforms look like for an AV Fistula in the graft pro and distal and in the ein prox and distal?
Connection from deep vein to superficial vein graft, via a non-ligated perforator
Graft proximal – low resistance
Graft distal – high resistance, low flow volume
Vein proximal – pulsatile
Vein distal – no change
what is the purpose of Percutaneous angioplasty (PTA)?
what types are there?
Access to obstruction via vessel
Palmaz - balloon deployed
Wallstent - self expanding
Dilatation with balloon
Stents: Post PTA. stent helps reduce restenosis
what are the peripheral vascular stent sites?
Aorta
renals
iliacs
femoral - popliteal
carotid
what is this?
stent deployment
