Peripheral Vascular Disease

Question 1

How common is it?

Answer 1

Prevalence = 10%

Question 2

Who does it affect?

Answer 2

Older people, people with cardiac risk factors, more common in men.

Question 3

What causes it?

Answer 3

Occurs due to atherosclerosis causing stenosis of arteries via a multifactorial process involving modifiable and non-modifiable risk factors.

Question 4

What risk factors are there (and how can they be reduced)?

Answer 4

Cardiovascular risk factors:
•	Smoking. 
•	Diabetes mellitus. 
•	Hypertension. 
•	Hyperlipidaemia: high total cholesterol and low high-density lipoprotein (HDL) cholesterol are independent risk factors. 
•	Physical inactivity. 
•	Obesity

Question 5

How does it present?

Answer 5

Symptoms
• Cramping pain felt in calf, thigh or buttock after walking a given distance (claudication distance) and relieved by rest (calf claudication suggests femoral disease while buttock claudication suggests iliac disease).
• Ulceration, gangrene, and foot pain at rest (e.g. burning pain at night releived by hanging legs over side of bed) are cardinal features of critical ischaemia.
• Buttock claudication ± impotence apply Leriche’s syndrome.
• Young heavy smokers at risk from Buerger’s disease.

Signs
• Absent femoral, popliteal or foot pulses.
• Cold white legs.
• Atrophic skin
• Punched out ulcers (often painful)
• Postural/dependent colour change.
• A vascular (Buerger’s) angle of 15s are found in severe ischaemia.

Question 6

Which other conditions may present similarly?

Answer 6

The differential diagnosis of pain in the lower limb when walking includes sciatica and spinal stenosis, deep vein thrombosis, entrapment syndromes and muscle/tendon injury.

Question 7

How would you investigate the patient?

Answer 7

• Exclude DM, arteritis (ESR/CRP).
• FBC (anaemia, polycythaemia), U&E (renal disease), lipids (dyslipidaemia), ECG (cardiac ischaemia).
• Do thrombophilia screen and serum homocysteine if <50mmHg.
• Imaging - colour duplex USS is 1st line (non-invasive and readily available). If considering intervention, MR/CT angiography is used to assess extent and location of stenoses and quality of distal vessels

Question 8

Conservative treatments?

Answer 8

1. Risk factor modification - quit smoking (vital). Treat hypertension and high cholesterol. Prescribe an antiplatelet agent (unless contraindicated) to prevent progression and reduce cardiovascular risk.
2. Management of claudication - Supervised exercise programmes reduce symptoms by improving collateral blood flow. Encourage patients to exercise to the point of maximal pain. Vasoactvie drugs (eg. noftidrofuyrl oxalate) offer modest benefit and are recommended only in those who do not wish to undergo revascularization and if exercise fails to relieve symptoms.

Question 9

If conservative measures have failed and PAD is severely affecting a patient’s lifestyle or is becoming limb threatening, what interventions can be carried out?

Answer 9

• Percutaneous transluminal angioplasty (PTA) is used for disease limited to a single arterial segment (a balloon is inflated in the narrowed segment). Stents can be used to maintain artery patency.
• Surgical reconstruction: If atheromatous disease is extensive but distal run off is good (i.e. distal arteries filled by collateral circulation), consider arterial reconstruction with a bypass graft. Procedures includee femoral-popliteal bypass, femoral-femoral crossover and aorto-bifemoral bypass grafts.

Amputation - <3% of patients with intermittent claudication may require major amputation within 5 years. Amputation may relieve intractable pain and death from sepsis and gangrene. Knee should be preserved whenever possible as it improves motility and rehabilitation potential. Gabapentin can be used to manage phantom pain.