Abstract
Two patients with severe subarachnoid hemorrhage caused by vertebral artery (VA) dissecting aneurysms underwent endovascular coil embolization. As both patients developed devastating rebleeding, endovascular trapping was performed and the affected VA was occluded although the posterior inferior cerebellar artery (PICA) originated from the affected portion. Extraventricular drainage was placed for the accompanying acute hydrocephalus. Both patients developed massive cerebellar and brainstem infarction and deteriorated. Computed tomographic scans clearly showed upward dislocation of the brainstem beyond the tentorium. Clinical management of severe posterior fossa subarachnoid hemorrhage complicated by PICA involved VA dissection and acute hydrocephalus is hazardous, especially when rebleeding occurs. Tolerance to PICA and VA occlusion is unpredictable. Proximal VA occlusion or stent assisted embolization might have been an option in these two cases.
