Direct revascularization to the anterior cerebral artery territory in patients with moyamoya disease: report of five cases

In some patients with moyamoya disease, the development of spontaneous leptomeningeal collateral channels between the anterior cerebral artery (ACA) and other major arteries is poor. These patients require revascularization not only to the territory of the middle cerebral artery (MCA) but also to that of the ACA. For reliable revascularization to the ACA territory, we performed superficial temporal artery (STA)-ACA direct anastomosis in 5 of 58 patients with moyamoya disease who underwent cerebral revascularization at our institute during the last 8 years. Because two patients presented with ischemic symptoms corresponding to the ACA territory after the ipsilateral STA-MCA anastomosis, we subsequently performed STA-ACA anastomosis. In three patients in whom hypoperfusion in the ACA territory was suspected based on preoperative angiograms and/or stimulated cerebral blood flow studies, we performed STA-ACA and STA-MCA anastomoses during a single operative procedure. After paramedian frontal craniotomy (diameter, approximately 5 cm), STA-ACA anastomosis was performed at the convexity, using a cortical branch of the ACA as a recipient. An interposed STA graft was used in four patients; all of the grafts were shorter than 4 cm. Bypass flow was satisfactory in four patients. One patient who underwent simultaneous STA-ACA and STA-MCA anastomoses had poor bypass flow, probably caused by spontaneous leptomeningeal collateral channels between the ACA and MCA. No patient had an ischemic attack after surgery. Our method using a cortical branch of the ACA as a recipient and a branch of the STA for the interposed graft can be performed at the convexity and much more easily than in a deep operative field. Our experience with STA-ACA anastomosis indicates that this procedure is effective for revascularization of the ACA territory in patients with moyamoya disease.