Chronic peripheral arterial occlusive disease

Question 1

List the clinical manifestations of chronic peripheral arterial occulsive disease

(signs and symtoms)

Answer 1

Symptoms:

• The classic symptom is leg pain when walking which resolves with rest, known as intermittent claudication
• Ischaemic ‘cramping’ muscle pain on walking, relieved by rest
• Pain is reproducible at a similar level, the ‘claudication distance’
• Most commonly in the calf, suggesting femoral disease
• Pain in the thigh/buttock suggests ileal disease, which will often be bilateral
  
  • Associated absent penile function = Leriche syndrone

Signs:

• Absent pulses
• Cold, pale legs
• Atrophic, hairless & shiny skin
• Beurger’s angle <20 degrees
• Arterial ulcers

Question 2

How is chronic peripheral lower limb peripheral arterial disease classified?

Answer 2

The Fontaine classification outlines the progression of chronic lower limb peripheral arterial disease:

1. Asymptomatic
2. Intermittent claudication (a condition in which cramping pain in the leg is induced by exercise, due to narrowing of arteries)
3. Ischaemic rest pain
4. Ulceration/gangrene

Question 3

How can you differentiate between symptoms of ischaemic rest pain and neuropathy as a cause of chronic foot pain?

Answer 3

Peripheral neuropathy has 3 main effects whch ischaemic rest pain doesn’t:

• Sensory neuropathy
  
  • Reduces protective reactions to minor injury, and reduces awareness of symptoms of infection/ischaemia
• Autonomic neuropathy
  
  • A lack of sweating leads to development of dry, fissured skin, allowing entry of bacteria
• Motor neuropathy
  
  • Wasting of the small muscles of the foot lead to loss of the arches and development of abnormal pressure areas in the feet

Neuropathy is associated with tingling and numbness, and is not relieved by swinging a leg out of bed.

Neuropathy general conforms to a glove and stocking distribution.

Ischaemic pain will get worse on raising the leg; unlike neuropathic pain unless it is caused by nerve entrapment (Buerger’s test can differentiate for vascular causes as the leg will go pale).

Question 4

Describe the pathophysiology of intermittent claudication

(how and why does it occur)

Answer 4

• The calf is most often affected, as it the femoral artery that most comonly becomes atheromatous
• At rest, the oxygen requirement of muscles is met by the collateral system of the profunda femoris (therefore no pain)
• Exercise produces a demand that cannot be met, and the calf muscles become ischaemic
• By resting, the collateral system can once again supply enough blood for the pain to be relieved

Question 5

What are differential diagnosis for intermittent claudication? (other leg pain causes)

Answer 5

Spinal stenosis

• Most commonly due to spinal osteophyte formation
• Symptoms are due to lumbar nerve root/cauda equina compression
• Features similar to intermittent claudication, but pain is relieved by sitting down or flexing the spine rather than standing still
• Variable symptoms from day to day

Venous claudication

• Obstruction of the venous outflow of the leg (iliofemoral occulsion)
• Pain comes on gradually from the moment walking starts
• Pain affects the whole leg, and is ‘bursting’ in nature
• Leg elevation can relieve the pain
• There are signs of venous disease and often history of DVT

Other causes of leg pain are musculoskeletal (osteoarthritis/rheumatoid arthritis), pepherial neuorpathy, Buergers disease (young men, heavy smokers) or popliteal artery entrapment

Question 6

What is the conservative management of arterial occlusive disease?

Answer 6

• Lifestyle changes:
  
  • Stop smoking
  • Exercise to the point of claudication to improve collaterals
  • Weight loss
• Raising the heel of shoes (decrease calf work)
• Foot care to prevent minor trauma leading to ulceration ect.
• Optimisation of blood pressure (avoid B-blockers) and diabetes
• Started on antiplatelet (clopidogrel) and a statin (atorvastatin)

Question 7

How can you investigate arterial disease?

Answer 7

• Doppler ultrasound scan
• Duplex ultrasound scan
• angiography
• Ankle/Brachial pressure index
  
  • Management depends on ABPI result & level of symptoms

Intermittent claudication is associated with an ABPI of 0.4-0.9, values of <0.4 are associated with critical limb ischaemia. ABPI may appear higher than its actual value in calcified/hardened arteries