Fenestrated vertebral artery

Fenestrations of the vertebral arteries (VAs) are usually identified angiographically. A left fenestrated vertebral artery (fVA) is reported here, identified in an adult specimen by microdissection. The distal segment of this VA was fenestrated and it consisted of two arms, the caudal one being larger than the cranial one. The caudal end of the rostral arm and the left posterior inferior cerebellar artery (PICA) were inserted at the same point. The anterior spinal artery was leaving the caudal arm of the fVA. On that side the anterior inferior cerebellar artery (AICA) was rudimentary, its cerebellar hemispheric territory being supplied by the PICA. The rostral arm of the fVA and the AICA were united by an anastomosis coursing on the ventral side of the olive. The AICA-to-fVA anastomosis, as well as the PICA, were supplying perforator arteries of the retro-olivary sulcus. Anatomical details of various arterial morphologies are important during specific surgical and interventional procedures.