The investigators conducted a prospective multi-center study assessing the effect of direct bypass and indrect bypass in treatment of 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