Peripheral Vascular Disease

Atherosclerosis

• Affects medium and large arteries
• Caused by chronic inflammation and activation of the immune system in the artery wall
• This cause deposition of lipids in the wall, followed by fibrotic plaques
• These plaques can cause:
  • Stenosis leading to reduced blood flow (e.g. in claudication)
  • Rupture giving off a thrombus that blocks a distal vessel leading to ischaemia (e.g. in acute coronary syndrome)

Atherosclerosis Risk Factors

• Older age
• Family history
• Male
• Smoking and alcohol consumption
• Poor diet (i.e. high trans-fat and reduced fruit and vegetables and omega 3 consumption)
• Low exercise
• Obesity
• Diabetes

End Results of Atherosclerosis

• Angina
• Acute Coronary Syndrome
• Transient Ischaemic Attacks
• Strokes
• Peripheral Arterial Disease
• Chronic Mesenteric Ischaemia

Definitions

Peripheral Arterial Disease results from atherosclerosis and narrowing of the arteries supplying the limbs and periphery

Critical Limb Ischaemia is the end-stage of peripheral arterial disease, where there is an inadequate supply of blood to a limb to allow it to function normally at rest.

Intermittent Claudication is the symptom of having ischaemia in a limb during exertion that is relieved by rest. It is typically a crampy, achy pain in the calf muscles associated with muscle fatigue when walking beyond a certain intensity.

Leriche’s Syndrome

• Associated with occlusion in the distal aorta or proximal common iliac artery
• A clinical triad:
  • Thigh / buttock claudication
  • Absent femoral pulses
  • Male impotence

Examination

• Weak peripheral pulses
  • Radial
  • Brachial
  • Carotid
  • Aorta
  • Femoral
  • Popliteal
  • Dorsalis Pedis
  • Femoral
• Pallor
• Cold
• Skin changes (ulceration, hair loss)
• Buerger’s Test
• You can use a handheld doppler to more accurately assess pulses

Investigation

• Ankle-Brachial Pressure Index (ABPI)
• Arterial Doppler
• Angiography (CT or MRI)

Ankle-Brachial Pressure Index

• The ratio of systolic blood pressure in the ankle (around the lower calf) vs the arm
• E.g. an ankle SBP of 80 and an arm SBP of 100 gives a ratio of 0.8
• Results
  • >0.9 is normal
  • 0.6 – 0.9 is mild disease
  • 0.3 – 0.6 is moderate to severe disease
  • <0.3 is severe disease to critical ischaemic

Critical Limb Ischaemia (6 P’s mnemonic)

• Pain
• Pallor
• Pulseless
• Paralysis
• Paraesthesia
• Perishing cold

Management of Intermittent Claudication

• General lifestyle changes to reverse modifiable risk factors (diet, smoking, exercise etc)
• Optimise medical treatment of comorbidities (hypertension, diabetes etc)
• Medical treatments
  • Atorvastatin 80mg
  • Clopidogrel 75mg once daily (alternatively aspirin plus dipyridamole)
  • Naftidrofuryl oxalate (peripheral vasodilator)
• Surgical treatments
  • Angioplasty and stenting
  • Bypass Surgery

Managing Critical Limb Ischaemia

• Urgent referral to vascular team
• Analgesia
• Urgent revascularization by
  • Angioplasty and stenting
  • Bypass surgery