Arterial (Quiz 4)

Question 1

What are the treatment options for PAD?

Answer 1

medical treatment, surgical reconstruction/bypass grafting, endovascular therapy

Question 2

The type of intervention depends on what?

Answer 2

disease location and extent

Question 3

List the five endovascular treatment types.

Answer 3

balloon angioplasty, stent angioplasty, atherectomy, subintimal angioplasty, and stent-graft angioplasty

Question 4

When is endovascular intervention preferred?

Answer 4

preferred for focal, less than 5cm in length regions of stenosis

Question 5

What are patient risk factors associated with angioplasty failure?

Answer 5

lesion calcification, occlusions, poor tibial runoff, diabetes mellitus, renal failure

Question 6

Three ways to surveillance things?

Answer 6

segmental pressures, segmental plethysmography, duplex sonography

Question 7

What is surveillance used for?

Answer 7

to look for failure of intervention, and progression of disease
perform studies immediately post-procedure

Question 8

What is PTA?

Answer 8

percutaneous translumenal angioplasty

Question 9

What is the failure rate for PTA within the first year? And is highest within….

Answer 9

20-40%

the first 6 months

Question 10

What are the expectations of indirect physiologic testing after treatment?

Answer 10

• in claudicant, ABI should improve to normal
• all patients should show improved ABI of at least >0.2
• in critical limb ischemia patients, toe pressure should have increased to predict healing (at least 30-40mmhg)
• duplex scan may not be needed if ABI is normal

Question 11

Hemodynamic information provides what?

Answer 11

functional and anatomic assessment

Question 12

With no stenosis, what velocity information should be expected with duplex imaging?

Answer 12

<50% diameter reduction
PSV of <180 cm/s
Velocity ratio of <2
a normal digital artery waveform

Question 13

With a moderate stenosis, what velocity information should be expected with duplex imaging?

Answer 13

>50% diameter reduction
PSV of 180-300 cm/s
velocity ratio of 2-3.5
end diastolic velocity greater than zero
monphasic waveform

Question 14

With a severe stenosis, what velocity information should be expected with duplex imaging?

Answer 14

>70% diameter reduction
PSV >300 cm/s
velocity ratio of >3.5 
end diastolic velocity greater than 45 cm/s
dampened, monophasic, and lower velocity

Question 15

With an occulded artery, what velocity information should be expected with duplex imaging?

Answer 15

no flow will be detected and a dampened, monophasic, low velocity waveform may be present

Question 16

When should reintervention be scheduled?

Answer 16

greater than 70% stenosis

Question 17

Because use of angioplasty and stenting doesn’t remove plaque, PSV values may be higher in these areas due to what?

Answer 17

plaque dissection, stent geometry, myointimal hyperplasia, and decreased arterial wall compliance

Question 18

Angioplasty failure can manifest as occulsion or stenosis. Test findings on in-stent stenosis include:

Answer 18

lumen reduction, elevated PSV values (200-300 cm/s), reduction in ABI, and damped, low-velocity spectral waveform distally

Question 19

List the three types of grafts.

Answer 19

prosthetic (synthetic) bypass graft, autogeneous vein, and in-situ vein

Question 20

Describe a synthetic bypass graft.

Answer 20

made of various manufactured materials (PTFE - teflon, Dacron - polyester)
associated with poor long term patency rates

Question 21

Describe an autogeneous bypass graft.

Answer 21

autogeneous vein is the preferred graft material; has better long term patency rates; must be carefully monitered in short term for early complications and failure

Question 22

What veins may be used for an autogeneous bypass graft?

Answer 22

cephalic or basilic veins
greater saphenous or lesser saphenous veins
radial artery

Question 23

What may cause au autogeneous bypass graft to fail?

Answer 23

veins have valves, so graft may be reversed and work against blood flow

Question 24

Describe an in situ vein for a bypass graft.

Answer 24

the vein being used for bypass is left in its original anatomic position; the branches of the vein must be ligated and valves must be lyzed to allow blood to flow downward; the large end of the vein is anastomosed to the large end of the artery while the small end of the vein is anastomosed to the small end of the artery

Question 25

What is an orthograde graft?

Answer 25

when the vein is freed from it's original position and involved lyzing of the valves

Question 26

What is a retrograde bypass graft?

Answer 26

when the freed vein is flipped so the valves do not need to be removed; the large end of the vein is anastomosed to the small end of the artery and vice versa

Question 27

Orthograde and retrograde bypass grafts only relate to which grafts?

Answer 27

autogeneous

Question 28

Where does the proximal anastomosis usually occur?

Answer 28

at the CFA or SFA

Question 29

Where does distal anastomosis usually occur?

Answer 29

popliteal artery (above or below knee) or tibial artery

Question 30

During the first 30 days of the graft, what technical problems are more likely to occur?

Answer 30

retained valve or valve leaflet; intimal flap; problems at anastomotic site due to suture placement; graft entrapment due to improper positioning; and thrombosis due to inadequeate conduit or limited runoff

Question 31

What problems may occur between 1 and 24 months of the graft?

Answer 31

myointimal hyperplasia (usually at valve site); stenosis at proximal or distal anastomosis

Question 32

What is the most common cause of graft revision in the time period of 1-24 months?

Answer 32

stenosis at prox or distal anastomosis

Question 33

What problems may occur after 2 years of the graft?

Answer 33

progression of atherosclerotic disease in inflow or outflow vessels; waveform characteristics must be carefully monitored for changes in diastolic flow, increases in acceleration time, decreases in PSV; aneurysmal dilation

Question 34

When is the bypass graft routinely surveillanced?

Answer 34

first ultrasound performed within 3 months postoperative; within the first year, surveinllanced every three months; second year surveillanced every 6 months; and annually thereafter

Question 35

What patients may need more than routine scanning?

Answer 35

those with intraoperative revision, early postoperative revision of thrombectomy, and/or limited venous conduits

Question 36

What are signs that the graft is not healing?

Answer 36

acute onset of pain; diminished or absent pedal pulses; persistent nonhealing ulcers; recent history of loss of limb swelling; poor physiologic testing results (ABI decrease of more than 0.15 between exams)

Question 37

When imaging a graft with duplex imaging, what should be imaged with color Doppler and PSV?

Answer 37

inflow artery, proximal anastomosis, mid-graft, distal anastomosis, outflow artery

Question 38

Why should transverse view be used to image the graft?

Answer 38

to gain an overview of anastomotic sites and graft itself

Question 39

How is the graft usually anstomosed?

Answer 39

to native vessel in an end-to-side orientation

Question 40

What is the primary goal of duplex examination of a graft?

Answer 40

to document anatomic and hemodynamic characteristics of bypass graft and adjacent vessels

Question 41

What are the pitfalls of duplex scanning?

Answer 41

obesity may limit exam; deeply placed grafts may require lower frequencies; dressings, skin staples, and sutures limit access to portions of graft

Question 42

How does a vein graft appear? PTFE graft?

Answer 42

vein: smooth and uniform walls, intimal-medial layer visible PTFE: wall should be smooth and uniform, distinct double line appearance

Question 43

How should plaque be characterized?

Answer 43

homogeneous/heterogeneous, calcification noted, smooth/irregular surface

Question 44

What is a retained valve?

Answer 44

valve or valve remnant that remain due to incomplete valve disruption during surgery larger remnants or valve leaflets can produce flow limiting stenosis - appears as bright echoes within graft lumen

Question 45

What is myointimal hyperplasia?

Answer 45

rapid proliferation of cells into the intimal layer; it can occur at any point along bypass conduit, but typically occurs in areas where vein has sustained injury or valve sinus

Question 46

What other abnormalities can be found from the bypass?

Answer 46

dissections, intimal flaps, aneurysms, pseudoaneurysms, hematomas or other perigraft fluid collections

Question 47

With spectral Doppler, a normal bypass should demonstrate what?

Answer 47

multiphasic waveform with sharp upstroke and narrow systolic peak high resistance (reversal component may be absent in early postoperative period; forward flow in diastole may also be in indication of hyperemia or arteriovenous fistula

Question 48

What is an arteriovenous fistula?

Answer 48

abnormal connection between artery and vein

Question 49

When does an AV fistula take place?

Answer 49

when branch of GSV is left unligated, creating a connection between venous system and arterial system blood flow can be diverted into deep venous system

Question 50

How will spectal Doppler look proximal to the fistula?

Answer 50

low resistance pattern with continuous antegrade flow in diastole

Question 51

How will the waveform look distal to the fistula?

Answer 51

little or no diastolic flow will be present

Question 52

A distal stenosis or occlusion (sample taken proximal to the stenosis/occlusion), what will the waveform look like?

Answer 52

blunted, monophasic with no diastolic flow abnormally high resistance energy loss, lower velocities can progress to staccato waveform

Question 53

What will the waveform look like with a proximal stenosis?

Answer 53

continuous diastolic flow and prolonged rise to peak systole

Question 54

Analysize velocites with stenosis.

Answer 54

normal: below 150 cm/s abnormal: >180 cm/s greater than or equal to 50% stenosis: PSV of 180-300 cm/s and PSV ratio of 2 greater than or equal to 75% stenosis: PSV greater than 300 cm/s and PSV ratio of 3.5

Question 55

What is the mean graft flow velocity?

Answer 55

additional parameter to access bypass graft patency | calculated by taking average of 3-4 PSV values in nonstenotic graft segments at various levels

Question 56

What is the normal GFV?

Answer 56

greater than 45 cm/s

Question 57

What is an abnormal GFV?

Answer 57

less than 40 cm/s consistent with large graft diameter or those with limited outflow decrease in GFV or more than 30 cm/s indicates pending graft failure