Extracranial-intracranial Bypass Surgery Versus Medical Treatment Alone for Symptomatic Chronic Middle Cerebral Artery Occlusion: the CMOSS-2 Trial
The CMOSS-2 trial is a government-funded, prospective, multicenter, randomized controlled trial. It will recruit symptomatic chronic occlusion of the middle cerebral artery in patients with severe hemodynamic insufficiency. Only high-volume center with a proven track record will be included. Patients will be randomized (1:1) to best medical treatment alone or medical treatment plus bypass surgery. Primary outcome is ischemic stroke in the territory of the target artery within 24 months after randomization.
• 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.