Peripheral Artery Disease

Question 1

What is Poiseulle’s Law?

Answer 1

• 70% stenosis is where we start operating
  
  • pulsatile flow– important for optimal organ function

Question 2

Why is the diabetic patient at increased risk of amputation?

Answer 2

• Risk amputation increased due to:
  
  • reduced sensation in feet
  • reduced resistance to infectin
  • reduced arterial flow
  • deformity of the food (charcot joint)
• Ischemia & Infection

Question 3

What is something to look out for in a diabetic patient that would indicate they are having a reduced blood flow to their limbs?

Answer 3

If they shuffle or step really high

indicated a loss of sensation

Question 4

What are the clinical findings of peripheral artery disease?

Answer 4

• Claudication
  
  • b/c lack of blood flow, have lack of oxygen
    
    • increases monocytes, neutrophils, free radicals, and lactic acidosis (the burning)
    • source of blockage will be one segment above where they are having pain
• Leriche Syndrome
  
  • ​pain of claudication in buttox or hips
  • indicative of an aorta or aortic/iliac disease
• Rest Pain
  
  • if blood flow extremely decreased
  • have to get up and walk around in the middle of the night, often sleep with legs hanging over side of bed
• Ischemia, gangrene

Question 5

What are the “6-Ps” for Peripheral Artery Disease?

They are the same “6-Ps” for what other syndrome

Answer 5

• 6 Ps- intermittend claudication in claves or arch of feet
  
  1. pulselessness
  2. pain
  3. pallor
  4. paresthesia
  5. Poikilothermy (cold)
  6. paralysi
• Same as compartment syndrome

Question 6

What finding would you expect to see upon physical examination of a patient with peripheral artery disease?

Answer 6

• physical examination
  
  • bruits, thrills (buzzing)
  • skin temperature
  • capillary refill
  • ulcers
• Pulse examination
  
  • carotids
  • radial
  • brachial
  • femoral
  • popliteal (hard to feel)
  • dorsalis pedis
  • posterior tibial
• Monofilament testing
  
  • ask them to close their eyes and drag a small wire across:
    
    • front of shins, sides of legs, top of foot, heel and toes
    • note neuropathies

Question 7

What is the purpose of taking an ABI?

What do you do if it abnormal?

Answer 7

the pressure in the legs should be higher than the pressure in the arms

If it is abnormal (below 0.9) you take a lower-extremity arterial doppler

Question 8

What does Duplex ultrasound measure?

What do brighter colors on the scan indicate?

Answer 8

• measures peak systolic & end-diastolic blood velocities to estimate severity of stenosis
• fast arterial velocity (indicated by brighter colors on scan) indicates narrowing of artery

Question 9

If the Doppler indicates disease, what is the next diagnostic step?

What is helpful about this next step?

Answer 9

• Angiogram
  
  • definitive method of srterial diagnosis prior to selecting intervention
  • provides anatomical informaiton about lesion
  • shows surrounding anatomy including branch arteries

Question 10

If a limb becoes gangrene within about 6 hours of complete occlusion, how do people with severe blockages not have gangrene limbs?

Answer 10

The blockage did not happen overnight. As the disease progressed, other arteries develop collateral branches to supply the ischemic area

Question 11

The provided angiogram is missing what major artery?

Answer 11

the left hypogastric (internal iliac)

Question 12

What artery is missing in the provided angiogram?

Answer 12

From lateral to medial: anterior tibial artery, peroneal artery, and posterior tibial

Missing: right posterior tibial

Question 13

What are strategies for risk factor reduction for peripheral arterial disease?

Answer 13

• stop smoking
• diet
• cholesterol control
• hypertension control
• diabetic control
• ambulation, aerobic exercise

Question 14

Describe the mechanism of action for Clopidogrel (Plavix)?

Answer 14

Blocks ADP receptor P₂Y₁₂, an extra carbodymethyl side group

Question 15

What does the drug, Cilostazol (pletal), do?

Answer 15

drug for last resort

inreases endogenous nitric oxide & nitrogen carries oxygen to the tissues better then oxygen on its own

It also makes the RBC more maleable so they are able to get through the

Question 16

What are conservative treatment approaches to peripheral artery disease?

Answer 16

• ambulation, aerobic exercise
• platelet inhibitors- aspirin, plavix
• multivitamins
• vitamin E, 400IU daily
• Vitamin C, 1000mg daily
• B-complex vitamins with B₆, B₁₂, and folic acid
• omega 3 fish oil
• cilostazol (pletal)
• continued close obersvartions

Question 17

Identify the branches of the aorta

Answer 17

Question 18

Identify the arterial branches of the leg

Answer 18

Question 19

Where do blockages most commonly occur?

Answer 19

they often occur at bifurcations– specifically superficial & deep femoral

have a bigger artery coming into smaller arteries, causing friction and then the blood bangs into the bifurcation, causing a little injury/friction

Question 20

What are the forms of invasive treatment for peripheral artery disease?

Answer 20

• angioplasty
  
  • balloons, now about 80% making it to a year
• stenting
• cryoplasty
  
  • freezes the artery & the plaque will liquify and be carried away & we don’t get apoptosis
• anthrectomy devices, laser, and brachytherapy
  
  • paque is moved or excised by laser
• bypass– veins, prosthetic grafts
  
  • often used with long lesions
• endoprosthetic devices,
  
  • viabahn

Question 21

What are the 3 indications for amputation?

Answer 21

• pain
• sepsis, multiple organ failure
• hygeine

Question 22

What are the steps to a preoperative evaluation?

Answer 22

• cardiac clearance – stress testing
• pulmonary function testing
• beta blocker protocol