Aneurysm

An aneurysm is an abnormal blood-filled swelling of an artery or vein, resulting from a localized weakness in the wall of the vessel.

Aneurysm
Diagnosis in short
Temporal artery aneurysm. H&E stain.
Gross	dilation of blood vessel
Site	mostly cerebral, blood vessels
Clinical history	variable
Prognosis	dependent on size, location and subtype

Aortic aneurysm

Main article: Aortic dissection

• Dilation < 1.5 times

• 

  Aortic dissection (WC).

• 

  Mycotic pulmonar aneurysm (Yale Rosen).

Cerebral (intracranial) aneurysm

Clinic

• usu. asymptomatic.
  • after rupture: sudden severe headache, nausea, vision impairment, vomiting, loss of consciousness.

Classification

• Size:
  • Small < 15 mm, large (15 to 25 mm), giant (25 to 50 mm) and super-giant (> 50 mm).
• Shape:
  • Saccular, Fusiform
• Location:

Micro

• Berry aneurysm:
  • See Cerebral saccular aneurysm.
• Fusiform aneurysm:
  • often middle segment of basal arteries.
  • enlagement: several centimeters.
  • marked atreriosclerosis (histiocytes, hemorrhage, calcification, inflammation).
• Infective aneurysm:
  • high mortality (30% in bacterial, 90% in fungal).
  • seen in 3% of patients with infectious endocarditis.
  • history of drug abuse.
  • inflammation of the vessel wall (ectasia).
    • usu. from the adventitia inwards.
  • Presence of microorganisms.

Image

• 

  Cerebellar aneurysm (Dr. Bollinger / WC)

See also

• Cerebral saccular aneurysm.
• Subarachnoid hemorrhage.