Vertebral-posterior inferior cerebellar artery aneurysm in a patient presenting with subclavian steal phenomenon: A case report

Abstract

A 75-year-old woman, whose radial pulse had been faint on the left side for the previous 15 years, suddenly experienced a severe headache, followed by loss of consciousness. Computed tomography obtained by a local doctor revealed a subarachnoid hemorrhage. She was referred to our hospital and subsequently admitted. On admission, she was stuporous, but her consciousness level improved to moderate confusion by the next day. Vertebral angiography revealed a right vertebral-posterior inferior cerebellar artery aneurysm as well as the retrograde filling of the left vertebral artery. The left subclavian artery was occluded at the origin presumably due to atherosclerosis. The aneurysmal neck was clipped successfully through a right lateral suboccipital approach. The postoperative course was uncomplicated except for transient hoarseness, and the patient was discharged 36 days after admission. Intracranial vertebral artery aneurysm in patients diagnosed with subclavian steal phenomenon is extremely rare. The increased hemodynamic stress in the vertebral artery, induced by contralateral proximal subclavian or innominate artery occlusions, may play a role in the development of the aneurysm.