Current status of the revascularization surgery for moyamoya disease

Abstract

Moyamoya disease is a chronic cerebrovascular disease with unknown etiology characterized by steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network at the base of the brain. Moyamoya disease has unique and dynamic nature to convert the vascular supply for the brain from internal carotid(IC) system to the external carotid(EC) system. Malfunction of this‘IC-EC conversion system’leads to cerebral ischemia,as well as to intracranial hemorrhage from inadequate collateral vascular network,both of which represent the clinical presentation of moyamoya disease. Therefore,surgical revascularization by extracranial-intracranial bypass is the optimal procedure to complement‘IC-EC conversion’,thereby preventing cerebral infarction and/or intracranial hemorrhage. Long term outcome of revascularization surgery is favorable,and the recent randomized control trial,such as the Japan Adult Moyamoya trial,further supports the validity of this procedure for moyamoya disease. Cerebral ischemia and hyperperfusion syndrome are potential complications of this procedure,which should be carefully managed by intensive perioperative care. We sought to review the current status of revascularization surgery for moyamoya disease,especially focusing on pre-operative diagnosis,surgical indication/procedure,and peri-operative management.