Inclusion Criteria:  Subjects who were diagnosed as moyamoya disease by the diagnostic criteria recommended by the Research Committee on MMD of the Ministry of Health and Welfare of Japan in 2012. Suzuki stage: 2-5 stage Age: between 18 and 65 years old Subjects present with ischemic stroke or transient ischemic attack. Subjects who plan to accept the first EDAS surgery. Informed consent obtained from patient or patient's surrogate  Exclusion Criteria:  Acute ischemic stroke occurred within one month. Suffered Intracranial hemorrhage before Subjects with large infarction spread widely over the territory of a main arterial trunk Aneurysms in the main arterial trunk Severe cardiac diseases like atrial fibrillation，valvular disease，heart failure, infective endocarditis and so on. Malignant tumors or severe disordered function of the heart, lung, liver or kidney. Severe hemostatic disorder or severe coagulation dysfunction. Uncontrolled diabetes mellitus with a serum fasting blood glucose level>300 mg/dL, or requires insulin; hypertension with a systolic blood pressure over 180 mmHg or a diastolic blood pressure over 110 mmHg. Severe injury on upper limbs. Pregnant or lactating women. Life expectancy is less than 3 years. Patients who are not suitable for this trial considered by researchers for other reasons