Direct Cerebral Bypass Supplements Indirect Bypass Procedures in Moyamoya Disease

Moyamoya disease is a unique disease of unknown etiology characterized by progressive occlusion of the supraclinoid portion of bilateral internal carotid arteries (IC), and the proximal portions of anterior (ACA) and middle cerebral arteries (MCA). Occlusion of the posterior circulation is also involved in 30–40% of patients. In most of the recommended procedures till date, either direct and/or indirect bypass surgery has been advocated to improve cerebral perfusion. In the present study, we performed combined surgery that included both the direct bypass procedures as well as the indirect ones [1,2]. The combination of procedures ensured perfusion of a wider ischemic zone and salvaging of the penumbric area. Indirect procedures like encephalo-duro-arterio-synangiosis (EDAS), encephalo-myo-synangiosis (EMS) or galeal flaps are safe and easy. Direct bypass surgery, however, is more reliable in providing adequate cerebral blood flow but is technically difficult as the recipient artery running on the cortical surface is usually fine and fragile in moyamoya disease.