Concurrent Fenestrations of the Basilar and Anterior Cerebral Arteries.

Intracranial arterial fenestrations are infrequent variants of the cerebral arterial circle, which generally occur due to incomplete embryological fusion during vascular development. These fenestrations hold clinical significance because of their association with modified hemodynamics and the potential for aneurysm formation. The present imaging report highlights a unique double intracranial fenestration incidentally identified during magnetic resonance angiography (MRA) of a 53-year-old female patient. The initial fenestration was identified in the basilar artery (BA) at the vertebrobasilar junction, measuring 9.22 mm in length and featuring symmetrical limbs, one of which branched off into an aberrant posterior inferior cerebellar artery (PICA). The second fenestration was identified in the anterior cerebral artery (ACA), originating 6.01 mm distal to the internal carotid artery, forming a 4.01 mm arterial ring that ended at the anterior communicating artery (AComA). The coexistence of 2 fenestrations in the same individual is infrequent, with limited documented cases. This case underscores the significance of comprehensive vascular imaging in detecting these morphological variants, which could affect cerebrovascular pathology and guide surgical planning.