Multiple Aneurysms on Inter-PICA Communicating Collaterals: Case Report on a Rare Entity

Aneurysms arising from the posterior inferior cerebellar artery (PICA) to PICA communicating collaterals are very rare. Only five cases have so far been described in the literature. Here, we report the first case with multiple aneurysms occurring on separate inter-PICA communicating collateral arteries, where one of the PICA's was occluded proximally and reconstituted distally through the inter-PICA collateral arteries, in a patient presenting with subarachnoid hemorrhage. After standard management, the ruptured aneurysm was resected, and the other unruptured aneurysm was clipped. Side-to-side PICA-to-PICA anastomosis distal to the communicating collaterals was performed in order to maintain collateral circulation to the brainstem. Clinicians should be aware of the possibility of these rare aneurysms, and should consider in situ bypass in the management of PICA aneurysms where the aneurysm is proximal to the telovelotonsillary segment of PICA. Categories: Neurosurgery