Aneurysm

Aneurysms are focal abnormal dilatation of a blood vessel. They typically occur in arteries, venous aneurysms are rare. Aneurysms may also occur in the heart.

Pathology

Pathological types

1. true aneurysm
2. false aneurysm (or pseudoaneurysm)

Causes

• congenital
• atherosclerosis
• hypertension
• vasculitis
• hereditary connective tissue disorders
  • Marfan syndrome
  • Ehlers-Danlos syndrome
• fibromuscular dysplasia
• infection: mycotic aneurysm, syphilis (luetic aneurysm)
• trauma
• iatrogenic
• myocardial infarction: may cause left a ventricular aneurysm
• flow related (in cerebral AVM, contralateral ICA occlusion etc)

Morphology

Morphologically there are two main types of aneurysms. The morphology is not specific for any cause:

1. saccular aneurysm: eccentric, involving only a portion of the circumference of the vessel wall
2. fusiform aneurysm: concentric, involving full circumference of the vessel wall

Occasionally a 3^rd type, serpentine aneurysm has been classified as a separate entity ³.

Complications

• rupture
• distal thromboembolism
• pressure effects

See also

• thoracic aortic aneurysm
• abdominal aortic aneurysm
• popliteal artery aneurysm
• cerebral berry aneurysm
• coronary artery aneurysm
• splenic artery aneurysm
• coeliac artery aneurysm
• mycotic aneurysm