Peripheral vascular disease: claudication and critical ischemia

Question 1

Define peripheral vascular disease

Answer 1

PVD = disease of the arteries (not in brain or heart).

Question 2

Describe the epidemiology of PVD

Answer 2

• More men affected than women

- In US: 12% of the population have PVD

Question 3

Describe the aetiology of PVD

Answer 3

1. ) Atherosclerotic plaque: gradual
2. ) Thromboembolism: CLI
   - CLI also caused by emboli, graft occlusion and trauma

Question 4

What are the risk factors for developing PVD

Answer 4

• Smoking
• Dyslipidaemia
• Hypertension (HTN)
• Diabetes mellitus

Question 5

Describe the pathology of PVD

Answer 5

• Atherosclerotic plaque is a build up of lipid/fibrous material and calcium. This begins as fatty streaks that build up in a persons arteries. This results in a narrowing of the arteries that commonly affects lower limbs most severely. This causes intermittent claudication and gangrene as blood cannot get to more distal points. Arteries it affects:
• Thromboembolism: sudden cause of PVD, happens when a blood clot blocks artery, preventing blood flow

Question 6

What are the clinical presentations (signs) of PVD

Answer 6

Intermittent claudication:

• Round shaped, slow healing ulcers (punched out ulcers)
• Absent pulses
• Affected areas are hairless
• Postural colour change (Buerger’s Test): foot turns white when elevated and red when lowered
• 6 P’s of limb ischaemia: Pain/pallor/pulseless/perishing cold/paraesthesia/paralysis (also applies to critical leg ischaemia
• CLI: deep duskiness of limb + sudden deterioration shows arterial occlusion or cellulitis/foot pain at resr

Question 7

What are the symptoms of PVD

Answer 7

• Intermittent claudication: achy nerve pain caused by release of adenosine in response to muscle ischemia. Results in two symptoms: cramping pain in calves/thighs buttocks when active and pain relieved by rest
• Critical leg ischaemia: pain in thigh/calves/feet/buttocks and ulcers

Question 8

Describe the investigations for PVD

Answer 8

To exclude DM/arthritis/anaemia/renal disease:

1. ) ABPI (ankle brachial pressure index): normal is 1-1.2 but PAD will be 0.5-0.9
2. ) Colour Duplex USS: quick/non-invasive. Can show vessels and blood flow
3. ) MRI/CT angiography: identify stenosis + quality f vessels
4. ) Bloods: raised CK-MM shows muscle damage
5. ) Auscultation: bruit

Question 9

Give an example of a differential diagnosis for PVD

Answer 9

DM/arthritis/anaemia/renal disease

Question 10

What are the treatment options for PVD?

Answer 10

1. ) Lifestyle: smoking cessation/healthier diet/losing weight/regular exercise
2. ) Medical:
   - First line: antiplatelet therapy: clopidogrel
   - Anticoagulants: aspirin
   - Lipid lowering drugs (statins): Atorvastatin
   - Diabetes drugs
3. ) Surgical: percutaneous transluminal angioplasty

For critical leg ischaemia: surgical embolectomy/local thrombolysis with t-PA (risk of repurfusion injury)

Question 11

What arteries are affected in PVD

Answer 11

1. ) Hip/buttocks pain: aorta or iliac arteries
2. ) Thigh: common femoral artery
3. ) Upper 2/3rd of calf: superior femoral artery
4. ) Lower 1/3rd of calf: popliteal artery
5. ) Foot: tibial/peroneal artery

Question 12

Describe buerger’s test

Answer 12

1. ) Patient supine: elevate legs to angle of 45 degrees and hold. Observe colour of feet. Peripheral arterial pressure can’t overcome gravity so pallor happens
2. ) Sit patient uo and ask them to hang their legs down over the side of the bed at 90 degree angle. Gravity aids blood flow, colour returns to ischaemic leg. Skin is blue and then red (due to reactive hyperaemia)

Question 13

What are the 4 stages of chronic limb ischaemia

Answer 13

1. ) Stage I: asymptomatic
2. ) Stage II: intermittent claudication
3. ) Stage III: rest pain/nocturnal pain
4. ) Stage IV: necrosis/gangrene