Observations on moyamoya disease: a case treated with superficial temporal-middle cerebral artery anastomosis.

A 24-year-old Caucasian woman with Moyamoya disease was treated by a superficial temporal, middle cerebral artery anastomosis. Her pre and postoperative angiograms revealed that the telangiectatic network in the region of the basal ganglion served as a transcerebral collateral circulation from the internal carotid artery proximal to its occlusion to the cortical branches of the middle cerebral artery. The transit through two capillary systems (basal ganglia and cortical) explains the slow circulation time. Prompt venous drainage was seen to occur once a more direct collateral supply was established by the superficial temporal-middle cerebral artery anastomosis.