Endovascular Management of a Ruptured Aneurysm on a Posterior Inferior Cerebellar Artery with Extradural C2-Origin: Case Report and Literature Review.

Extracranial vascular pathology uncommonly causes intracranial subarachnoid hemorrhage (SAH). Among possible lesions are aneurysms at the craniocervical junction arising from a posterior inferior cerebellar artery (PICA) with an extradural origin. We describe a case of a 55-year-old female presenting with a sudden and severe headache. A computed tomography scan revealed a SAH within the fourth ventricle and cervical spinal canal, and a ruptured saccular aneurysm on a PICA with extradural C2-origin. Despite difficult access anatomy, endovascular treatment was feasible and resulted in subtotal initial occlusion and preservation of distal PICA flow. Upon 3-month follow-up, the aneurysm was completely occluded with a patent PICA. The patient's clinical status remained stable at the 1.5-year follow-up. In conclusion, we present a rare case of an aneurysm originating from a PICA with extradural C2-origin that was treated endovascularly with preservation of the PICA.