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 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 5.26% at autopsy
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.