Vascular: Chronic and Critical Limb Ischaemia

Question 1

What is the pathophysiology of chronic limb ischaemia?

Answer 1

Peripheral arterial disease = symptomatic reduced blood supply to the limbs

Atherosclerosis

Question 2

What are the risk factors for chronic limb ischaemia

Answer 2

Smoking

DM

HTN

Hyperlipidaemia

Increasing age

FH

Obesity and physical inactivity

Question 3

How is chronic limb ischaemia symptoms classified?

Answer 3

1 = asymptomatic

2 = intermittent claudication

• a = >200m
• b = <200m

3 = rest pain

4 = ulcers, gangrene

Question 4

What investigations should be performed for chronic limb ischaemia?

Answer 4

Buerger’s test = lying supine, raise legs until they go pale, lower them until the colour returns, angle at which limb goes pale is termed Buerger’s angle, <20 degrees = severe ischaemia.

ABPI

Doppler = to assess severity and location of occlusion

CT/MR angiography

CVS assessment = BP, BM, lipid profile, ECG

Question 5

How can critical limb ischaemia be defined?

Answer 5

1. Ischaemic rest pain for > 2 weeks, requiring opiate analgesia
2. Ischaemic lesions or gangrene objectively attributable to the arterial occlusive disease
3. ABPI (ankle-brachial pressure index = ankle systolic : brachial systolic) less than 0.5

Question 6

How should chronic and critical limb ischemia be managed?

Answer 6

Lifestyle advice (smoking cessation, regular exercise, weight reduction)

Statin therapy (ideally atorvastatin 80mg OD)

Anti-platelet therapy (ideally clopidogrel 75mg OD)

Optimise diabetes control

Angioplasty with or without stenting

Bypass grafting, typically used for diffuse disease or in younger patients

Amputations = pts that are unsuitable for revascularisation

Question 7

What are the possible complications from chronic and critical limb ischaemia?

Answer 7

Sepsis

Acute-on-chronic ischaemia

Amputation

Reduced mobility and QoL