De Silva K Ranil D, Silva Rukmal, De Silva Chandu, Gunasekera W S L, Dias P, Jayesekera R W
Department of Anatomy, Faculty of Medical Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka.
Ann Indian Acad Neurol. 2010 Jul;13(3):198-201. doi: 10.4103/0972-2327.70886.
The purpose of this study was to examine the degree of contribution from the vertebrobasilar and carotid systems to the origin of the PCA in fetal autopsy brains of last trimester of pregnancy and to compare with published data on the configuration of adult and fetal brains in a population of Sri Lankan origin.
The external diameter of the PcomA, pre-communicating part (P1), and the post-communicating part (P2) of posterior cerebral artery (PCA) of 34 fetal brain in the last trimester of pregnancy (30 to 40 weeks of gestation) was measured using a stereomicroscope equipped with a micrometer calibrator.
The blood supply to the occipital lobe mainly via the PCA was seen in 25 (59%) of fetal brains as compared to that in the literature 220 (93%) in adults brains and the blood supply to the occipital lobe mainly via the internal carotid artery (ICA) was seen in 16 (34%) of fetal brains as compared to 25 (7%) of adults brains (P < 0.0001), transitional configuration where the PcomA is equal in diameter to P1 segment of the PCA was seen in 5 (7.4%) of fetal brains and 8 (2%) of adults brains.
The present study reveals that from the newborn to the adult there is shift from carotid system to the vertebrobasilar system, this justifies further studies on different racial and geographic regions which may give a clearer picture about the cerebral hemodynamics from childhood to adult.
本研究旨在探讨妊娠晚期胎儿尸检脑内椎动脉基底动脉系统和颈动脉系统对大脑后动脉（PCA）起源的贡献程度，并与斯里兰卡裔人群中已发表的成人大脑和胎儿大脑结构数据进行比较。
使用配备测微校准器的体视显微镜测量34例妊娠晚期（妊娠30至40周）胎儿大脑大脑后动脉（PCA）的后交通动脉（PcomA）、交通前段（P1）和交通后段（P2）的外径。
与文献报道的成人大脑中220例（93%）主要通过PCA供应枕叶血液相比，25例（59%）胎儿大脑主要通过PCA供应枕叶血液；与成人大脑中25例（7%）主要通过颈内动脉（ICA）供应枕叶血液相比，16例（34%）胎儿大脑主要通过ICA供应枕叶血液（P<0.0001）；5例（7.4%）胎儿大脑和8例（2%）成人大脑中观察到PcomA直径与PCA的P1段相等的过渡构型。
本研究表明，从新生儿到成人，存在从颈动脉系统向椎动脉基底动脉系统的转变，这为进一步研究不同种族和地理区域提供了依据，可能会更清楚地了解从儿童到成人的脑血流动力学情况。
