Arterial dissection

Arterial dissection occurs when blood enters the media through a tear or ulcer in the intima and tracks along the media, forming a second blood-filled channel within the wall. The normal lumen lined by intima is called the true lumen and the blood-filled channel in the media is called the false lumen. The false lumen is at a higher pressure than the true lumen due to poor outflow.

Pathology

Etiology

In most cases the vessel wall is abnormal.

• hypertension ³ (pathogenesis: medial degeneration)
• inherited connective tissue disorders (pathogenesis: medial degeneration)
  • Marfan syndrome
  • Ehlers-Danlos syndrome
  • arterial tortuosity syndrome: very rare
• atherosclerosis (pathogenesis: penetrating ulcer)
• vasculitides (pathogenesis: inflammation)
  • e.g. Behcet disease
• pregnancy (pathogenesis: unknown)
• iatrogenic: aortic catheterization, intra-aortic balloon pump
• relapsing polychondritis (rare): pathogenesis?

Locations

• aortic dissection
• ICA dissection
• vertebral arterial dissection
• intracranial arterial dissection
• visceral arterial dissection