How I do it? Posterior inferior cerebellar artery-intracranial vertebral artery reimplantation bypass and trapping of dissecting aneurysm involving the proximal posterior inferior cerebellar artery.

BACKGROUND: Proximal posterior inferior cerebellar artery (PICA) aneurysms are surgically challenging due to the high variability in the anatomy of the PICA origin, their deep-seated nature, and their entanglement with the lower cranial nerves. Direct or reconstructive clipping may not be achievable if the aneurysm is large, or dissecting, or exhibits atherosclerosis or calcification.

METHOD: We present a case of a proximal PICA lateral medullary segment (P2) aneurysm that was successfully cured by trapping the aneurysm and reconstructing the PICA using the PICA-intracranial vertebral artery (PICA-V4) via end-to-side reimplantation bypass with the far lateral approach.

CONCLUSION: This case demonstrates the feasibility and safety of PICA-V4 reimplantation bypass, especially if the origin of the PICA is highly seated and the intracranial VA, or V4 segment, is long enough and well-exposed supra or under hypoglossal nerves.