C22 Ruptured blood blister-like aneurysm arising from fenestrated basilar artery

<h3>Introduction</h3> Blood blister-like aneurysms (BBA) arise mostly at the internal carotid artery (ICA). We report a case of a ruptured BBA from a branch of a fenestrated basilar artery (BA) that was successfully treated with coil embolization. <h3>Case Description</h3> A 41-year-old female was diagnosed with subarachnoid hemorrhage (figure A). Digital subtraction angiogram showed rebleeding at the small branch of the fenestrated BA (figure B, C). We planned to trap a ruptured area while saving the right anterior inferior cerebellar artery (AICA). Enterprise (4.0*16mm, figure D, white arrowhead) was deployed from the larger fenestrated BA to the proximal BA with jailing two microcatheters located at the ruptured site (figure D, small black arrow). Then trapping was attempted, but it was not possible because the AICA could not be saved. Another microcatheter was navigated retrogradely through the left posterior communicating artery of ICA and positioned at the right AICA origin (figure D, small white arrow). Trapping of the BBA was performed using three microcatheters while preserving the AICA (figure E). After embolization, an infarction in the pons was observed on DWI (figure F), but there was no neurologic deficit. <h3>Conclusions</h3> Although BBA arising in the posterior circulation is rare and difficult to treat, various neurointerventional approaches can adequately solve it. <h3>Conflict of Interest</h3> No