Extracranial-intracranial Bypass Surgery for Symptomatic Chronic Middle Cerebral Artery Occlusion: the CMOSS-2 Trial

Prior treatment

• Previous treatment with EC-IC bypass surgery
• Having received a clinical trial drug or device within 30 days prior to screening, or being enrolled in another clinical trial;

Other illness

• History of intracranial hemorrhage, subarachnoid hemorrhage, subdural hemorrhage, or extradural hemorrhage within 6 weeks;
• Unstable angina pectoris or myocardial infarction, congestive heart failure within 6 months;
• Other diseases with a life expectancy of less than 2 years
• Known allergy or contraindication to aspirin or clopidogrel or other antiplatelet drugs.
• Uncontrolled hypertension with a sitting systolic blood pressure \>180 mmHg or a sitting diastolic blood pressure \>110 mmHg;
• Active peptic ulcer disease;
• Other diseases or medical history that, in the judgment of the investigator, may affect the efficacy or safety evaluation of this study.

Lab values

• Coagulation dysfunction or hemorrhagic tendency (e.g. INR \> 1.5 and/or platelet count \< 100,000 mcL);
• Known cardiac conditions that may lead to cardiogenic embolism: including prosthetic valves, infective endocarditis, left atrial or left ventricular thrombosis, atrial fibrillation, sick sinus node syndrome, atrial mucinous tumor or cardiomyopathy, ejection fraction \<25%;
• Allergy to iodine or x-ray contrast, blood creatinine \> 3.0 mg/dl or other contraindications to arteriography
• Uncontrolled diabetes mellitus with fasting blood sugar (FBS) \>16.7 mmol/L
• Severe liver dysfunction, defined as serum alanine transaminase (ALT) and/or glutamic oxalacetic transaminase (AST) \> 3 times the upper limit of normal range;

Other

• Women who are pregnant or lactating;
• Persistent worsening of neurological symptoms within 72 hours;

• Age of 18-65 years;
• Confirmed as chronic occlusion of unilateral middle cerebral artery (MCA) by digital subtraction angiography (DSA) or computed tomography angiography (CTA). Other cerebral artery stenosis should be less than 50%.
• CT perfusion demonstrates severe hemodynamic insufficiency in the territory of the qualifying MCA with MTT (symptomatic side) ≥ 6s or rCBF (symptomatic side/contralateral side) ≤ 0.8;
• mRS score is 0-2 points;
• A history of ischemic events (including\<1/2 cerebral infarction in the middle cerebral artery supply area, or transient ischemic attack \[TIA\]) related to the qualifying artery within 12 months ;
• The onset of acute stroke should be more than 1 month;
• CT or MRI excludes large cerebral infarction (infarction\>1/2 of the territory of the qualifying middle cerebral artery);
• Patients or their guardians voluntarily participate of the study and sign the consent form.