Blood blister-like aneurysm

Blood blister-like aneurysm is a broad-based bulge at a non-branch point of a vessel, which is unlike saccular (or 'berry') aneurysms which usually occur at branch points.

Middle-aged patients with subarachnoid hemorrhage.

A focal defect in the arterial wall covered with fibrous tissue is usually seen. Potential causes include atherosclerotic vascular disease with ulceration, hemodynamic stress, and dissection.

  • shape: blood blister-like or half-domed shallow outpouching with wide neck
  • common sites: supraclinoid ICA (dorsal wall), less likely MCA, ACA, basilar artery
  • size: usually small (<6 mm) with a mean of 3 mm 1
  • rapid change in size and morphology on follow-up angiograms
  • CT angiography: often negative
  • digital subtraction angiography: is the best diagnostic tool

These aneurysms are difficult to treat:

  • endovascular coiling is difficult due to their small size and wide neck; flow-diverter stents are an acceptable alternative 4
  • surgical clipping carries a high risk of tearing the aneurysm or internal carotid laceration during surgery

They have a higher complication rate than saccular aneurysm because they are often missed on CTA, have a higher rate of rebleed, tend to rupture at a smaller size and have a high risk of rupture if there is an underlying dissection (45% in a small series) 4,5.  

Article information

rID: 47875
Tag: cases, cases
Synonyms or Alternate Spellings:
  • Small saccular aneurysm
  • Tiny saccular aneurysm

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Cases and figures

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  • Case 2
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