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