Occurs when a tear in the tunica intima of the aorta creates a false lumen whereby blood can flow between the inner and outer layers of the walls of the aorta

Aetiology

• Usually presents in men over the age of 50

Risk factors

• Hypertension
• Connective tissue disease e.g. Marfan's syndrome
• Valvular heart disease
• Cocaine/amphetamine use

Pathophysiology

Stanford classification

• Stanford Type A: involves the ascending aorta, arch of the aorta
  • 2/3 of cases
  • Associated with Marfan’s
• Stanford Type B: involves the descending aorta
  • 1/3 of cases
  • Associated with atherosclerosis and (rarely now) syphillis

Clinical features

Symptoms

• Sudden onset 'tearing' chest pain or interscapular pain radiating to the back
• It can also present with (depending on how far the dissection extends):
  • Bowel/limb ischaemia
  • Renal failure
  • Syncope

Signs

• Radio-radial delay seen in type A
• Radio-femoral delay seen in type B
• Blood pressure differential between arms