Giant thrombosed vertebral artery aneurysm treated by extracranial-intracranial bypass and aneurysmectomy--case report.

A 42-year-old male presented with a giant thrombosed aneurysm of the left vertebral artery. The aneurysm was resected through a combined subtemporal and suboccipital approach after a saphenous vein bypass graft was placed between the right external carotid artery and the posterior cerebral artery. Intraoperative measurements of the blood flow volume and pressure demonstrated good blood flow in the bypass. Postoperatively, uncontrollable hypertension resulted in huge intracerebral hematoma formation and increased intracranial pressure. Control of systemic hypertension is essential in such patients.