Abstract
Blood-blister like aneurysms (BBAs) are challenging lesions because of their wide fragile neck. Flow-diverting stents (FDSs), such as the Pipeline Embolization Device (PED), have been applied to treat BBAs less amenable to more established techniques of treatment. However, the use of FDSs, including the PED, in acute subarachnoid hemorrhage (SAH) still remains controversial. We report a case of aneurysm regrowth following PED application for a ruptured BBA that overlapped the origin of the dominant posterior communicating artery (PCoA), which was successfully treated after coil trapping of the origin of the fetal-type PCoA. And, we discuss the clinical significance of the fetal-type PCoA communicating with a BBA in terms of PED failure.