Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.
Keywords: AICA; BA; EC-IC; IEL; MR angiography; MRA; PCA; PCFA; PED; PICA; Pipeline; Pipeline embolization device; SAC; SAH; SCA; STA; VA; anterior inferior cerebellar artery; basilar artery; bypass; coil; embolization; extracranial-intracranial; fusiform; internal elastic lamina; posterior cerebral artery; posterior circulation fusiform aneurysm; posterior inferior cerebellar artery; stent-assisted coiling; stroke; subarachnoid hemorrhage; superficial temporal artery; superior cerebellar artery; vertebral artery.