Encephalo-myo-synangiosis (EMS) in moyamoya disease -with special reference to postoperative angiography (author's transl)

Abstract

Surgical treatments to increase cerebral blood flow in moyamoya disease such as STA-MCA anastomosis, encephalo-myo-synangiosis (EMS), encephalo-duro-arterio-synangiosis (EDAS) and omentum transplantation have been reported. Thirteen EMS and three EMS with STA-MCA anastomosis were performed on 12 patients with moyamoya disease, and the postoperative angiograms were analyzed. EMS was followed by recovery of paresis, disappearance of involuntary movement and disappearance or decrease of TIA. Half of the patients showed some recovery of the disturbance of intelligence. Younger patients recovered better than the adult cases. Complications after EMS were a case of transient dysarthria and dysphasia, a case of transient focal convulsvie seizure, a case of subcutaneous wound infection and a chronic subdural hematoma. No more severe side effects of EMS were seen. Selective external carotid angiograms performed over three months after EMS showed extensive filling of the cortical branches of the middle cerebral artery via the fine vascular networks fed by enlarged deep temporal arteries. New anastomoses between the cortical arteries and the middle meningeal artery were demonstrated in four cases. Moyamoya vessels in the region of the basal ganglia decreased in most cases after EMS. Modified EMS in which only the deep sheath of the temporal muscle was used for covering the cerebral surface had a similar effect. This method had less cosmetic disadvantage and less compression of the brain by blocking of the planted muscle. The postoperative external carotid angiograms disclosed multiple irregular narrowing, stenosis and occlusion of the cortical branches of the middle cerebral artery with fine revascularization in the distal region away from the site of EMS. These findings suggested that the primary occlusive process had spread over the cortical branches of the middle cerebral artery. Surgical treatments such as EMS and STA-MCA anastomosis should be tried on patients with moyamoya disease, especially in (1) younger cases, (2) cases with ischemic neurological deficit and/or (3) progressive cases.