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. 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 MRA
  • up to 5% at autopsy

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 aneurysm formation at the site of fenestration, presumably due to abnormal flow dynamics. They are reported in 7% of fenestrations.

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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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    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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