Abstract
Microsurgical anatomy of the middle cerebral artery, important for extracranial-intracranial bypass surgery in the Moyamoya disease, was studied in 50 hemispheres removed at autopsy, using 3-20 X magnification. The lateral surface of the brain was divided into 12 areas as proposed by Salamon and Michotey. Special attention was directed to the relationship of the branches to cerebral cortex and Sylvian fissure. The largest cortical branches found were the temporo-occipital and angular arteries. The distance of each vessel's superficial course, important factor for anastomosis, averaged more than 12mm and there was no regional difference. The posterior end of the Sylvian fissure, where suitable vessels of sufficient intraluminal diameter and length to permit bypass surgery are ordinarily available, was 6.6cm on average above the external auditory meatus. Using the cantho-meatal line and the standard points obtained from the results, a new, simple, and accurate method for approaching each vessel of 12 areas is proposed. The implication of these findings for bypass surgery for Moyamoya disease is reviewed.
