Flow dynamics in acute ischemic stroke due to embolic occlusion of a fetal posterior cerebral artery treated with endovascular thrombectomy - report of two cases.

The fetal variant of the posterior cerebral artery (fPCA) conserves a major blood flow from the anterior to the posterior cerebral circulation via a strong persistent caudal portion of the embryonic internal carotid artery. We present two cases where endovascular treatment in acute ischemic stroke was complicated by this flow diversion. Though direct thrombectomy of the fPCA using a stent retriever was feasible and successful in both cases outcome remained unfavourable due to a continuous redirection of embolic material into the posterior circulation. Knowledge of flow dynamics in a fPCA is important for endovascular treatment in acute ischemic stroke.