Abstract
Posterior circulation aneurysms include aneurysms of the posterior inferior cerebellar artery (PICA), the superior cerebellar artery (SCA), the vertebral artery (VA), the basilar artery (BA), the posterior cerebral artery (PCA), and the anterior inferior cerebellar artery (AICA). They occur less frequently than their anterior circulation counterparts, yet are more prone to rupture at a smaller size. This favors intervention over observation in many scenarios. Microsurgical options for treatment include clipping, with more complex scenarios requiring aneurysm trapping and bypass, excision and reanastomosis, and proximal or distal parent artery occlusion. This chapter is organized based on aneurysm location, focusing on the three most common aneurysm types in the posterior circulation (SCA, BA, PICA). The nuances surrounding patient selection and operative technique are emphasized, both of which are paramount to successful outcomes.