Basilar artery fenestration

Basilar artery fenestration (or more simply, basilar fenestration) is the most common intracranial arterial fenestration. It refers to duplication of a portion of the artery, thought to occur due to failed fusion of plexiform primitive longitudinal neural arteries 4. Its reported prevalence is highly variable depending on the technique used:

  • ~0.5% (0.3-0.6%) at angiography (presumably low due to preferential laminar flow in only one lumen at a time)
  • 2% on MR angiography
  • up to 5% at autopsy 5

Typically fenestration occurs at the lower end of the basilar artery just as the vertebral arteries join. However, it can also be seen in the mid-basilar and distal tip.

Related pathology

There is an increased incidence of basilar artery aneurysm formation at the site of fenestration, presumably due to abnormal flow dynamics. They are reported in 7% of fenestrations.

Anatomy: Brain
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Article information

rID: 5870
Section: Anatomy
Synonyms or Alternate Spellings:
  • Basilar fenestration
  • Fenestration of the basilar artery

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Cases and figures

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    CE-MRA: RAO MIP
    Case 1
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    Basilar artery fe...
    Case 2: small
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    Case 3: distal
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    Case 4
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    Case 5: with aneurysm
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    Case 6
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    Case 7
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    Case 8: CT
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