Blister Like Pseudoaneurysm

Synonyms:

Blood blister-like aneurysm a.k.a. blister-like pseudoaneurysm a.k.a. trunk aneurysm

Pathology:

  • Atherosclerosis with ulceration & hematoma
  • A small defect in the vessel wall covered only with overlying fibrous tissue
  • Atherosclerosis in parent vessel

Diagnosis:

Catheter Angiography:

  • Small lateral wall bulge (asymmetric i.e. only one side of the lateral wall), hemispherical in shape
  • Usually <10mm
  • May be read as negative
  • Usually in internal carotid artery, but can occur in Posterior communicating artery PCOM

CT: SAH may occur
CTA:

  • Asymmetrical bulge of arterial wall
  • Often false-negative on CTA

MRI: features of SAH
MRA: may show it or be negative

Treatment:

Very difficult and controversial. Treated if they rupture, options:

  • Endovascular:
    • Multiple overlapping flow diverting stents
    • Stent assisted coiling
    • Parent vessel sacrifice
  • Surgical:
    • Surgical wrapping

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