De Silva K R D, Silva T R N, Gunasekera W S L, Jayesekera R W
Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
Neurol India. 2009 Jan-Feb;57(1):46-9. doi: 10.4103/0028-3886.48821.
The degree of contribution from the vertebro-basilar and carotid systems to the origin of the posterior cerebral artery (PCA) is of clinico-anatomical importance. Three configurations in the bifurcation of the posterior communicating artery (PcomA) have been described, foetal, transitional and adult.
To examine the extent of contribution from the vertebro-basilar and carotid systems to the origin of the PCA in adult autopsy brains in subjects who had died of causes unrelated to the brain.
The external diameter of the PcomA, pre communicating part (P1) and the post communicating part (P2) of PCA in 225 normal Sri Lankan adult cadaver brains was measured using a calibrated grid.
The adult configuration was present in 220 (93.3%); (bilaterally in 200 (88.8%), and unilaterally in 20 (8.8%) ten on each side. Foetal configuration was seen in 17 (4.4%); bilaterally in 3 (1.3%), and unilaterally in 14 (6%) 8 on the left and 6 on the right. Transitional configuration was seen in 8 (2.2%); bilaterally in 2 (0.9%), and unilaterally in 6 (2.5%) 2 on the left and 4 on the right.
This study reveals that the internal carotid artery (ICA) provided the major supply to the PCA in 4.4% of foetal and 2.2% of transitional configurations. The adult configuration was present in 220 (93.3%), the highest recorded in the literature. This finding may be of relevance to vertebrobasilar ischaemia and infarcts in the territory of the PCA.
椎基底动脉系统和颈动脉系统对大脑后动脉（PCA）起始部的供血程度具有临床解剖学意义。后交通动脉（PcomA）分叉处已描述有三种形态，即胎儿型、过渡型和成人型。
研究在死于非脑相关病因的成人尸检大脑中，椎基底动脉系统和颈动脉系统对PCA起始部的供血程度。
使用校准网格测量225例正常斯里兰卡成人尸体大脑中PcomA、PCA的交通前段（P1）和交通后段（P2）的外径。
成人型在220例（93.3%）中出现；双侧200例（88.8%），单侧20例（8.8%），左右各10例。胎儿型在17例（4.4%）中出现；双侧3例（1.3%），单侧14例（6%），左侧8例，右侧6例。过渡型在8例（2.2%）中出现；双侧2例（约0.9%），单侧6例（2.5%），左侧2例，右侧4例。
本研究表明，在4.4%的胎儿型和2.2%的过渡型中，颈内动脉（ICA）为PCA提供主要供血。成人型在220例（93.3%）中出现，为文献中所记录的最高比例。这一发现可能与PCA区域的椎基底动脉缺血和梗死有关。
