Peripheral Arterial Disease

Question 1

What is the underlying process that causes PAD?

Answer 1

Atherosclerotic disease- 65% have co-existing cerebral and coronary artery disease

Question 2

What are some of the symptoms of PAD?

Answer 2

Intermittent claudication- there is pain on exertion in the area supplied by the diseased vessel
Ulceration
Hair loss
Pain on elevation of the leg

Question 3

Describe the nature of intermittent claudication and the processes underlying it

Answer 3

Pain is brought on by exertion as the diseased vessel lumen is not large enough to meet the demands during exercise. This results in ischaemia distally which causes pain.

Question 4

Which area of the body is most commonly affected by PAD?

Answer 4

The lower legs

Question 5

What is the biggest risk factor for PAD?

Answer 5

Smoking

Question 6

What is the difference between thrombosis and embolisms?

Answer 6

A thrombosis is when a clot formed in the vessel obstructs that vessel
An embolus is when a clot is formed that travels to obstruct a vessel elsewhere- clots form on atherosclerotic plaques

Question 7

What do muscle cells release in ischaemia that causes pain to be felt?

Answer 7

Adenosine

Question 8

What is meant by critical ischaemia in PAD?

Answer 8

Critical ischaemia occurs when pain is felt at rest, often during the night time and patients describe having to hang their legs over the side of the bed to reduce the pain

Question 9

Why might people with significant PAD be asymptomatic at rest?

Answer 9

Due to the recruitment of collateral vessels that provide alternative routes of blood flow meaning ischaemia is not experienced

Question 10

Where would pain be felt in PAD affecting the lower aorta/iliac arteries?

Answer 10

Hips or buttocks

Question 11

Where would pain be felt in PAD affecting the iliac or common femoral?

Answer 11

Thigh

Question 12

Where would pain be felt in PAD affecting the superficial femoral artery?

Answer 12

Upper 2/3 of the calf

Question 13

Where would pain be felt in PAD affecting the popliteal artery?

Answer 13

Lower 1/3

Question 14

Where would pain be felt in PAD affecting the tibial or peroneal artery?

Answer 14

Foot

Question 15

Describe the blood supply to the lower limb?

Answer 15

Abdominal Aorta
Common Iliac
External Iliac—> Common Femoral Artery
Internal Iliac —> Pelvic blood vessels
Common Femoral Artery
Gives of Profunda Femoris (Supply to Thigh)
Continues as Superficial Femoral (travels through adductor canal)
Enters popliteal artery when entering the popliteal fossa
Divides into anterior and posterior tibial arteries
Posterior tibial descends and gives of peroneal/fibular artery (supplies lateral compartment of leg).
Posterior tibial passes posteriorly to the medial malleolus and then becomes the lateral and medial plantar arteries
Anterior tibial descends down and at the foot becomes the dorsalis pedis artery

Note- Dorsalis pedis gives off deep plantar artery which anastomoses with the lateral plantar artery to form the deep plantar arch

https://www.youtube.com/watch?v=JNczJx2ju3I

Question 16

When does the internal iliac become the common femoral?

Answer 16

When it crosses the inguinal ligament

Question 17

Where can the femoral artery be palpated?

Answer 17

At the mid inguinal point- halfway between the asis and the pubic symphysis

Note- midpoint of the inguinal ligament is the location of the deep ring- this is halfway between the pubic tubercle and the ASIS

Question 18

Describe the ulcers seen in PAD?

Answer 18

Painful
Sharp punched out lesions
Often over pressure points

Note- Neuropathic ulcers can also have a punched out appearance but sensation will be reduced whereas arterial ulcers are painful

Question 19

What are some of the risk factors for PAD?

Answer 19

As for atherosclerotic disease

Smoking
HTN
Diabetes
Hyperlipidaemia
Age
Male Gender
Family  History

Question 20

What are some signs of PAD?

Answer 20

Absent foot pulses
Hair loss
Arterial ulcers- sharp boundaries and punched out appearance
Bruit heard in the diseases artery
Cold and pale legs
Atrophic skin
Buerger's angle <20 degrees
Decreased CRT in the toes

Question 21

What is buerger’s angle?

Answer 21

Angle at which the leg goes pale when raised up off the bed

Question 22

What investigations should be done for PAD?

Answer 22

ABPI
Duplex- Ultrasound with a picture generated
CT/MR Angiogram

Question 23

Describe the values for ABPI that indicate PAD is present?

Answer 23

Normal is 1-1.2
PAD= 0.5-0.9
Critical limb ischaemia <0.5 or ankle systolic <50 mmHg

Question 24

What would cause falsely high values for ABPI?

Answer 24

Atheroscelrotic vessels- the calcification process makes them difficult to compress meaning that artificially high pressures are needed to compress them (this is greater than the actual systolic pressure)

Question 25

What value defines PAD for ABPI?

Answer 25

<0.9

Question 26

What value defines critical limb ischaemia for ABPI?

Answer 26

<0.5

Question 27

What is the treatment for PAD?

Answer 27

Risk factor reduction- this is because there is a far more concerning risk of MI/Stroke due to the systemic atherosclerotic disease process occuring

Conservative- Smoking cessation, alcohol reduction, diet and exercise, supervised exercise programmes
Medical- Statins, Antihypertensives, Anti-platelets (Clopidogrel 1st line), Glycaemic control
Surgical Interventions- Angioplasty, Stenting, Bypass Surgery, Amputation

Question 28

How do supervised exercise programmes help with PAD?

Answer 28

Improve collateral flow
Weight loss
Blood pressure reduction

Patients should exercise to the point of maximal pain