Peripheral Arterial System 3 Flashcards

1
Q

3What is the role of duplex doppler in the study of bypass graphs? 3

A
  1. Establish baseline hemodynamics
  2. Identify correctable lesions before graft thrombosis
  3. Provide information to aid in decision regarding treatment alternatives
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are indications for arterial bypass and stent surveillance duplex testing? 7

A
  1. Post- op follow up and routine surveillance
  2. Acute onset of pain
  3. Persistent, non-healing ulcers
  4. Decreased ABI >0.15 compared to previous exam
  5. Dismissed or absent peripheral pulses
  6. Recent history of loss of limb swelling and suggestive of graft failure and ischemia
  7. Pulsatile mass near an anastomotic site or intervention site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a Aoroto- Iliac stent or bypass?

A

Abdominal aorta to unilateral or bilateral iliac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Aorto-fem graft?

A

Abdominal aorta to unilateral or bilateral femoral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a Ax-fem graft?

A

Axillary to CFA, Axillary to FA or axillary to DFA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a fem fem graft?

A

Right CFA to left CFA or vice versa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Label the image

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are different types of synthetic grafts? 2

A
  1. PTFE
  2. Dacron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Label the image

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are autogenous bypasses or stents?

A

Vein bypasses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are different types of Vein bypasses? 4

A
  1. In- Situ vein
  2. Reversed vein
  3. Autogenous veins commonly used
  4. Modified biological grafts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is an in-Situ vein?

A

Vein left in original location with valves cut and branches lighted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a reveresed vein?

A

Vein is lighted, reversed and attached to arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some autogenous veins commonly used? 4

A
  1. Great saphenous vein
  2. Small saphenous vein
  3. Basilic vein
  4. Cephalic vein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some modified biological grafts? 3

A
  1. Human umbilical vein
  2. Cryopreserved saphenous vein
  3. Bovine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is composite graft?

A

Synthetic graft connected to vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are different types of bypass anastomoses? 3

A
  1. End to end
  2. End to side
  3. Side to side
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a mechanism of graft failure?

A

Early graft failure (<30days)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is early graft failure (<30 days) due to? 4

A
  1. Technical errors such as poor choice of inflow or outflow vessels, retained valves, intimal flaps, clamp injury, suture placement at the anastomotic site, etc.
  2. Undiagnosed hypercoagulable disorder can cause early thrombosis
  3. Graft infection is rare but possible
  4. Can occur without a mechanical defect or cause
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why would a graft fail within months 1-24?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why would be a mechanism of graft failure greater than 2 years?

A
  1. Atherosclerotic progression: can cause a stenosis within the inflow and outflow vessels
  2. Aneurysmal degeneration in mature vein grafts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the mechanism of trauma in terms of trauma?

A

Trauma to the graft can lead to thrombosis or Thromboembolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a mechanism of stent failure? 2

A
  1. Technical failures
  2. Disease location
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Stunting is often used to treat what?

A

Complicated lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Technical failures (<30 days post op) or >30 days post op is usually caused by what?

A

Re-current stenosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are common locations of graft obstruction? 5

A
  1. Valve site
  2. Anastomoses
  3. Inflow tract
  4. Outflow tract
  5. Graft kink
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Without any specific symptoms, ultrasound is performed on bypass grafts at what intervals?

A

Routine intervals as part of a standard postoperative care

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the arterial bypass graft/stent surveillance protocol? 7

A
  1. Supine, head slightly elevated. Externally rotate the hip and bend the knee
  2. Transducer
  3. Obtain Bilateral ABI’s
  4. Evaluate for abnormalities in the graft or stent
  5. Locate anastomotic site s
  6. Information about graft/ stent length
  7. Locate any previously occluded grafts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

In terms of the arterial bypass graft/ stent surveillance protocol, what do we do in terms of transducer selection? 4

A
  1. 5-7 linear for deep bypass grafts
  2. 10-12 linear for superficial, in Situ vein grafts
  3. 3-5 curvilinear for aorta or iliacs
  4. 10 CW probe for ankle/ arm pressures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Once the graft stent location is determined, obtain images with and without colour, and spectral of what? 7

A
  1. Inflow/ proximal native artery
  2. Proximal anastomosis
  3. Proximal graft/stent
  4. Mid graft/ stent
  5. Distal Graft/ stent
  6. Distal anastomosis
  7. Outflow/ distal native artery
32
Q

When a stenotic area is identified what must we do?

A

Walk the sample through and obtain PSVs and waveforms

33
Q

Where are three areas we “walk” the sample volume?

A
  1. Within 2cm proximal to the stenosis
  2. At the highest point within the stenosis
  3. Distal to stenosis
34
Q

After we walk the sample volume with stenosis what do we do? 3

A
  1. Document post stenotic turbulence and bruits
  2. Measure lumen narrowing in SAG and TRANS
  3. Repeat for other grafts/ stents if present
35
Q

Early post op patterns (first two months), may not be multiphasic and be low resistance due to what?

A

Reactive hyperaemia

36
Q

After the early post op period, waveform will be what?

A

Low resistance and monophasic in initial scans and should change to high resistance and multiphasic in follow up scans

37
Q

Graft material will determine the severity of what?

A

Stenosis

38
Q

What do we analyze with arterial bypass and stent surveillance duplex testing? 6

A
  1. ABI or TBI
  2. PSV and flow direction
  3. Velocity ratio
  4. Waveform patterns and changes including flow direction and post stenotic turbulence
  5. Image data
  6. Consider reasons that the image and velocity data may not agree
39
Q

What does a normal greyscale and colour look like for grafts/bypass? 5

A
  1. No intraluminal echoes
  2. Colour fills the lumen form wall to wall in SAG and TRV
  3. Vein graft walls are smooth and uniform
  4. Synthetic grafts have “double line” wall appearance
  5. Stent walls are typically seen within the lumen
40
Q

What does the normal inflow artery bypass look like? 2

A
  1. Multiphasic
  2. VR <2.0
41
Q

How does the normal proximal anastomosis graft present?3

A
  1. VR <2.0
  2. Bifurcations and branches- waveforms may display disturbed patterns which become normal distally
  3. Due to size changes, a large inflow artery feeding a small diameter graft may produce a higher VR
42
Q

What does a normal Body of graft/ stent look like with bypass/ stents? 2 (psv values)

A
  1. PSV <150cm/s and VR <2.0 throughout
  2. Vein grafts <4mm, PSV at least >40-45 cm/s
43
Q

In terms of a normal Body of graft/stent, larger grafts may demonstrate what?

A

Lower velocities, 35 cm/s

44
Q

In terms of a normal Body of graft/stent, waveform patterns should remain the same as what?

A

Inflow artery unless it displays hyperemic flow due to recent placement

45
Q

What does a normal distal anastomosis look like?

A
  1. usually there is a size change from a wider graft to a narrower artery which results in an increased velocity
  2. Normal VR is <3.0
46
Q

In a normal distal anastomosis, due to the vessel angle and size change, what happens to the waveform?

A

May display a disturbed pattern

47
Q

What does a normal outflow artery look like? 3

A
  1. Velocities remained unchanged
  2. VR <2.0
  3. Waveforms similar to graft/ stent body
48
Q

What are some abnormal stenotic disease features? 7

A
  1. Post stenotic turbulence
  2. Waveform changes
  3. Colour bruit
  4. Aliasing within the stenosis
  5. Increased PSV
  6. Spectral broadening
  7. Echogenic material
49
Q

In an abnormal graft/ stent what would greyscale and colour look like? 5

A
  1. Lumen reduction
  2. Residual valve cusps
  3. Aneurysmal dilation and thrombus in aging grafts
  4. Colour does not fill the lumen
  5. Aliasing within a stenosis
50
Q

What does an abnormal inflow artery look like with a graft/stent? 2

A
  1. VR >2.0 (indicates hemodynamically significant lesions >50%)
  2. Significant inflow artery obstruction is indicated by monophasic waveform pattern (at least 2cm proximal to the anastomosis)
51
Q

What does a abnormal proximal anastomosis look like with grafts/ stents? 2

A
  1. Hemodynamically significant stenosis (>50%)
  2. VR > 2.0 (or >3.0 if graft diameter is much smaller than the inflow vessel)
52
Q

What does an abnormal body of graft/stent (variable by lab or source) look like on any graft body?

A
  1. > 50% stenosis: PSV >180 and Vr >2.0
  2. > 70% stenosis: PSV >300 cm/s and Vr >3.5
53
Q

What does an abnormal graft/stent look like?3

A
  1. Impending vein graft failure
  2. Obstruction in the inflow tract
  3. Distal anastamosis or outflow tract obstruction
54
Q

In terms of the impending vein graft failure with an abnormal body of graft/stent, what does it entail? Think psv and size.

A

PSV <40-45 cm/s throughout a normally sized graft (<4mm in diameter)

55
Q

What does the obstruction in the inflow tract of a abnormal body of graft/stent look like?

A

Monophasic waveform in the graft

56
Q

What does the distal anastomosis or outflow tract obstruction look like with an abnormal body of graft/ stent?

A

High resistance or “staccato” pattern

57
Q

What does an abnormal distal anastomosis look like?2

A
  1. Vr >3.0
  2. Consider a size mismatch between the bypass and outflow artery if there is an increased velocity without intraluminal echoes
58
Q

What an abnormal graft/stent occlusion look like?2

A
  1. No flow detected by spectral doppler or colour in TRV and SAV
  2. Intraluminal echoes may be seen
59
Q

What does this image demonstrate?

A

Vein graft stenosis

60
Q

Label the image

A
61
Q

Label the classification of graft stenosis

A
62
Q

What does this image demonstrate?

A

In situ graft stenosis

63
Q

What does this image demonstrate?

A

The colour bruit that appears distal to a stenosis of a graft

64
Q

What does this image demonstrate?

A

A waveform of a graft stenosis IN the stenosis

65
Q

What is other pathology that can be seen with Abnormal arterial bypass?2

A
  1. Pseudoaneurysm
  2. Aneurysmal dilatation
66
Q

Where might pseudoaneurysms appear?

A

May occur at anastomotic sites

67
Q

What is aneurysmal dilatation?3

A
  1. Focal or diffuse enlargement 1.5x the proximal arterial segment
  2. Intraluminal thrombus may be seen within the aneurysm
  3. Occurs most commonly in native artery near the anastomosis
68
Q

What does this image demonstrate?

A

Vein graft aneurysm

69
Q

Arteriovenous fistulas are unique to what type of grafts?

A

In-situ bypass grafts

70
Q

Arteriovenous fistulas are a tributary of what?

A

The GSV which connects via a perforator with the deep system and is left un-ligated after creation of the bypass

71
Q

In the arteriovenous fistula the perforator vein as what?

A

A fistula from the graft into the deep system

72
Q

What does the proximal arteriovenous fistula look like?

A

Constant antegrade flow (monophasic)

73
Q

What does a distal arteriovenous fistula look like?

A

Bypass graft shows little to no diastolic flow

74
Q

Where can entrapment of graft occur?

A

Knee

75
Q

In terms of entrapment of a graft, if a knee slightly bent, what is seen?

A

Normal flow

76
Q

In terms of entrapment of a graft, if the knee is straight what is seen?

A

no flow is detected in the graft by doppler or colour flow

77
Q
A