Peripheral Arterial System 3 Flashcards
3What is the role of duplex doppler in the study of bypass graphs? 3
- Establish baseline hemodynamics
- Identify correctable lesions before graft thrombosis
- Provide information to aid in decision regarding treatment alternatives
What are indications for arterial bypass and stent surveillance duplex testing? 7
- Post- op follow up and routine surveillance
- Acute onset of pain
- Persistent, non-healing ulcers
- Decreased ABI >0.15 compared to previous exam
- Dismissed or absent peripheral pulses
- Recent history of loss of limb swelling and suggestive of graft failure and ischemia
- Pulsatile mass near an anastomotic site or intervention site
What is a Aoroto- Iliac stent or bypass?
Abdominal aorta to unilateral or bilateral iliac
What is a Aorto-fem graft?
Abdominal aorta to unilateral or bilateral femoral
What is a Ax-fem graft?
Axillary to CFA, Axillary to FA or axillary to DFA
What is a fem fem graft?
Right CFA to left CFA or vice versa
Label the image
What are different types of synthetic grafts? 2
- PTFE
- Dacron
Label the image
What are autogenous bypasses or stents?
Vein bypasses
What are different types of Vein bypasses? 4
- In- Situ vein
- Reversed vein
- Autogenous veins commonly used
- Modified biological grafts
What is an in-Situ vein?
Vein left in original location with valves cut and branches lighted
What is a reveresed vein?
Vein is lighted, reversed and attached to arteries
What are some autogenous veins commonly used? 4
- Great saphenous vein
- Small saphenous vein
- Basilic vein
- Cephalic vein
What are some modified biological grafts? 3
- Human umbilical vein
- Cryopreserved saphenous vein
- Bovine
What is composite graft?
Synthetic graft connected to vein
What are different types of bypass anastomoses? 3
- End to end
- End to side
- Side to side
What is a mechanism of graft failure?
Early graft failure (<30days)
What is early graft failure (<30 days) due to? 4
- Technical errors such as poor choice of inflow or outflow vessels, retained valves, intimal flaps, clamp injury, suture placement at the anastomotic site, etc.
- Undiagnosed hypercoagulable disorder can cause early thrombosis
- Graft infection is rare but possible
- Can occur without a mechanical defect or cause
Why would a graft fail within months 1-24?
Myointimal hyperplasia can develop and cause a stensois. Can occur anywhere in the bypass but occurs most often at a valve site or at either anastomosis site
Why would be a mechanism of graft failure greater than 2 years?
- Atherosclerotic progression: can cause a stenosis within the inflow and outflow vessels
- Aneurysmal degeneration in mature vein grafts
What is the mechanism of trauma in terms of trauma?
Trauma to the graft can lead to thrombosis or Thromboembolism
What is a mechanism of stent failure? 2
- Technical failures
- Disease location
Stunting is often used to treat what?
Complicated lesions
Technical failures (<30 days post op) or >30 days post op is usually caused by what?
Re-current stenosis
What are common locations of graft obstruction? 5
- Valve site
- Anastomoses
- Inflow tract
- Outflow tract
- Graft kink
Without any specific symptoms, ultrasound is performed on bypass grafts at what intervals?
Routine intervals as part of a standard postoperative care
What is the arterial bypass graft/stent surveillance protocol? 7
- Supine, head slightly elevated. Externally rotate the hip and bend the knee
- Transducer
- Obtain Bilateral ABI’s
- Evaluate for abnormalities in the graft or stent
- Locate anastomotic site s
- Information about graft/ stent length
- Locate any previously occluded grafts
In terms of the arterial bypass graft/ stent surveillance protocol, what do we do in terms of transducer selection? 4
- 5-7 linear for deep bypass grafts
- 10-12 linear for superficial, in Situ vein grafts
- 3-5 curvilinear for aorta or iliacs
- 10 CW probe for ankle/ arm pressures