Week 9: Lower Extremity Arterial Scanning

Question 1

CHRONIC ATHEROSCLEROTIC OBSTRUCTIVE DISEASE

1. Individuals usually suffer from ____
2. Pain is most located in the ____
3. Arterial obstruction will be ____ to the site of claudication symptoms

Answer 1

1. claudication
2. calf
3. proximal

Question 2

FLOW CHARACTERISTICS: STENOSIS

1. Pre stenotic: flow velocity is _____
2. At the site of stenosis, flow _____ within the stenosis and becomes turbulent distally
3. Arterial stenosis eliminates the ____ phase
4. Flow distal to the stenosis or post stenotic can be characterized as _____

Answer 2

1. decreased
2. accelerates
3. diastolic
4. biphasic or monophasic

Question 3

FLOW CHARACTERISTICS: STENOSIS

1. Proximal pulsatility changes, flow velocity ____
2. ____ velocity in the stenotic zone
   3.____ flow in the post stenotic zone
   4.Distal pulsatility changes, flow velocity decreased, ____ waveform noted

Answer 3

1. decreased
2. Increased
3. Disturbed (turbulent)
4. tardus-parvus

Question 4

FLOW CHARACTERISTICS: STENOSIS

Always take a PW sample prestenosis, at the area of stenosis, and post stenosis

Answer 4

Question 5

ARTERIAL STENOSIS GRADING

1. ____ - Divide the maximum PSV recoded across the stenosis by the PSV recoded in a normal area of the artery just proximal to the stenosis

2.____: focal doubling of the velocity suggests a > 50% arterial stenosis (If the maximal stenotic PSV doubles the pre stenotic PSV)

Answer 5

1. Peak systolic velocity ratio
2. Rule of thumb

Question 6

ARTERIAL STENOSIS GRADING
Jean Ellison at Cedars-Sinai Medical Center in LA:

> 2:1 ratio for ____ stenosis

Answer 6

> 50%

Question 7

ARTERIAL STENOSIS GRADING
Jean Ellison at Cedars-Sinai Medical Center in LA:

> 4:1 ratio for ____ stenosis

Answer 7

> 75%

Question 8

ACUTE ARTERIAL OCCLUSION

1. Symptoms are ____, severely ____, and _____
2. _____ have not had time to develop

Answer 8

1. immediate, painful, cyanotic
2. Collaterals

*note: no color/PW Doppler flow or collaterals formes yet

Question 9

What are the causes of acute arterial occlusion? (2)

Answer 9

1. Thrombotic: from thrombus formation at an aneurysm or pseudoaneurysm
2. Embolic: from thrombus or other material traveling from a proximal level to plug a stenotic segment of the artery

Question 10

HEMATOMA VS PSEUDOANEURYSM

What are they caused by?

Answer 10

Both can occur after a patient undergoes a cardiac catheterization procedure

Both are caused from the artery not closing well after accessing the femoral artery resulting in
blood escaping into the surrounding tissues

Question 11

What are the difference between hematoma and pseudoaneurysm?

Answer 11

Hematoma
- blood escaped the artery then clots and forms a mass
- homogenous and grainiy appearance sonographycally
- DO NOT have blood flow within

Pseudoaneyrysm
- blood continues to flow into and out of a discrete area in the tissue through the interrupted arterial wall (fails to seal)
- Sonographically the color flow pattern will look like a “yin-yang symbol”
- Treated by ultrasound guided thrombin injection

Question 12

What is this?

Answer 12

hematoma

Question 13

What is this?

Answer 13

pseudoaneurysm

*key is to find the neck. notice that there’s severe aliasing, it won’t close its own unless applying the pressure or use thrombin to clot the blood

Question 14

1. PW Doppler waveform within the pseudoaneurysm will demonstrate a____ pattern
2. Systole- ____ flow through the neck/tract into the pseudoaneurysm
3. Diastole- ____ flow out of the pseudoaneurysm due to the pressure being higher in the pseudoaneurysm than in the arterial lumen

Answer 14

1. “to-fro” flow *note: “to-fro” or “to and fro” - constant movement backward and forward.
2. antegrade
3. retrograde

Question 15

What are the 2 common treatment for pseudoaneyrysm?

Answer 15

1. Thrombin injection-most common
2. Hold transducer pressure over the area

Question 16

What is this?

Answer 16

arteriovenous (AV) Fistula

Question 17

What is AV fistula?

Answer 17

An abnormal communication between an artery and a vein

*appears arterial flow/pulsatation in veins = a sign of AV fistula

Question 18

AV Fistula:
1. can be ____ or ____
2. Caused when the ____ and ____ are punctured simultaneously
3. It can steal flow from distal circulation, causing ____
4. In severe an AV fistula it can reduce distal resistance so significantly it can cause some degree of ____
5. Most close on their own, do not need surgical intervention

Answer 18

1. congenital or acquired (from a femoral stick at cardiac cath)
2. artery, vein
3. ischemic symptoms
4. heart failure

Question 19

ARTERIOVENOUS (AV) FISTULA

1.Blood typically shunts from the ____ into the ____ at the site of the fistula
2.Loss of the triphasic waveform within the artery ____ to the fistula
3.Decreased blood flow within the artery ____ to the fistula
4.Increased pulsatile blood flow within the vein ____ to the fistula

Answer 19

1. artery, vein
2. proximal
3. distal
4. proximal

Question 20

BYPASS GRAFT SURVEILLANCE

1. Checks for graft ____ and to try to spot impending graft failure
2. Easily ____ and ____
3. Better to repair a narrowed graft than to start all over with a new one
4. Most lower extremity grafts are made using the patient’s ____*Better patency rate than synthetic material

Answer 20

1. patency
2. repeatable, harmless
3. greater saphenous vein (GSV)

Question 21

When a vein graft is not possible surgeons use a synthetic material

1. ____: sonographically has *a double-wall appearance
2. ____: sonographically has a fuzzier, wavy/woven appearance

Answer 21

1. Gore-Tex
2. Dacron

Question 22

What is this?

Answer 22

Gore-tex
*double walls

Question 23

What is this?

Answer 23

Dacron

Question 24

BYPASS GRAFTS

Grafts using the patient’s own GSV have 2 configurations (2 ways to get around the problem if valves allowing flow to only go cephalad)

What are 2 configuration?

Answer 24

1. in situ
2. reversed

Question 25

LOWER EXTREMITY BYPASS GRAFTS: TYPES (5)

Answer 25

1. **Aortoiliac and aortofemoral** -Provide flow around inflow obstructions -Frequently bilateral 2. **Femrofemoral** -Used when the iliac artery on one side is severely obstructed 3. **Axillofemoral** -Run from the axilla artery down to the common femoral artery -Commonly used in combination with femrofemoral grafts 4. **Femropopliteal** -Run from the common femoral artery down to the popliteal artery -Usually used to bypass obstructions in the superficial femoral artery 5.** Femrotibial and popliteal-tibial** -Can be used to try to perfuse a foot that is threatened by ischemia

Question 26

BYPASS GRAFT SURVEILLANCE 1. ____ : the attachment or connection of one vessel to another 2. Most common type of anastomosis in the lower extremities is the ____ (The end of the graft is joined to the side of the native artery). 3. Obstruction often develops at the ____ and ____ anastomoses due to the altered hemodynamics in these areas 4. ____ more commonly due to the** lower velocities** there 5. ____ sites also promote obstructive disease  Spectral velocities can be high within a graft shortly after it is installed, and lower over time

Answer 26

1. Anastomosis 2. end-to-side 3. proximal, distal 4. Distal 5. Valve

Question 27

What type of graft is this?

Answer 27

end-to-side

Question 28

most common type of graft

Answer 28

femropopliteal

Question 29

What type of graft is used to bypass obstruction in the superficial femoral artery?

Answer 29

femropopliteal

Question 30

What type of graft is used to perfuse a foot that is threatened by ischemia?

Answer 30

femrotibial or popliteal-tibial

Question 31

What type of graft commonly used with femrofemoral grafts?

Answer 31

axillofemoral

Question 32

What type of graft is used when the iliac artery on one side is severely obstructed?

Answer 32

femrofemoral

Question 33

What type of graft is used to provide flow around inflow obstruction and frequently bilatreral?

Answer 33

aortoiliac or aortofemoral