Direct Bypass Versus Indirect Bypass in Treatment of Adults Hemorrhagic Moyamoya Disease

Inclusion Criteria: 1. cerebral digital subtraction contrast angiography (DSA) revealed severe stenosis or occlusion of the distal internal carotid or proximal middle and anterior cerebral arteries with prominent lenticulostriate "moyamoya collaterals" 2. patients had experienced at least one intracranial hemorrhage which was verified by computed tomography (CT) scanning, magnetic resonance imaging MRI), or lumbar puncture. 3. Patients requiring surgery Exclusion Criteria: 1. Patient whose initial onset was marked by ischemia but subsequently suffered from intracranial hemorrhage 2. patients refused to participate in the study