MICROSURGICAL ANATOMY OF THE POSTERIOR PORTION OF WILLIS' CIRCLE AND THE POSTERIOR CEREBRAL ARTERY / 解剖学报

ABSTRACT

The posterior portion of Willis' circle and the posterior cerebral artery of 50Chinese brains(40 adults and 10 children)were systematically studied.The hypoplastic posterior communicating artery was found in 56.0%?4.96.The posterior communicating artery gave off,in average,5.3 perforating branchesto the hypothalamus and 3.5 perforating branches to the posterior perforatingsubstance.The posterior cerebral artery was divided into 3 segmentsP_1, P_2 and P_3.The segment P_1 of the posterior cerebral artery gave off,in average,1.8thalamoperforating branches to the interpeduncular fossa and 0.9 mamillary branchto the mamillary body.The segment P_2 gave off direct perforating branches,whichwere divided into 3 groupsin average 4.3 branches to the cerebral peduncule,1.0branch to the pulvinar and brachium quadrigeminum superius and 5.4 thalamogeni-culate branches.Moreover,the posterior cerebral artery also sent short circumflex branches tothe mesencephalic tegmentum,long circumflex branches to the mesencephalic tectum,medial posterior choroidal arteries to the choroid plexus of the third ventricle andlateral posterior choroidal arteries to the choroid plexus of the lateral ventricle.The blood stream of the segment P_2 mainly came from the basilar artery in79.0%?4.07,from the internal carotid artery in 4.0%?1.96 and equally from bothof them in 17.0%?3.76.The posterior cerebral artery sent off five cortical branches,and was mainlydistributed to the inferior surface of a temporal lobe and the medial surface of anoccipital lobe.