van Raamt A Fleur, Mali Willem P T M, van Laar Peter Jan, van der Graaf Yolanda
Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
Cerebrovasc Dis. 2006;22(4):217-24. doi: 10.1159/000094007. Epub 2006 Jun 20.
In a fetal-type posterior circle of Willis (FTP) there is an embryonic derivation of the posterior cerebral artery (PCA) from the internal carotid artery (ICA). Besides the fact that a larger area is thus dependent on the ICA, leptomeningeal vessels cannot develop between the anterior and posterior circulation. The tentorium namely prevents cerebellar vessels from connecting to the PCA territory. Therefore patients with an FTP could be more prone to develop vascular insufficiency. An overview of the literature is given. We propose to define a partial FTP, in which a small P1 segment between the basilar artery and the postcommunicating part of the PCA is present, and a full FTP, in which the P1 segment is absent. Whether a full FTP is a risk factor for stroke should be subject of further investigation.
在胎儿型威利斯后循环（FTP）中，大脑后动脉（PCA）由颈内动脉（ICA）胚胎发育而来。除了更大的区域因此依赖于颈内动脉这一事实外，软脑膜血管在前循环和后循环之间无法发育。小脑幕会阻止小脑血管与PCA区域相连。因此，患有FTP的患者可能更容易发生血管供血不足。本文对相关文献进行了综述。我们建议定义一种部分性FTP，即基底动脉与PCA的后交通部之间存在一小段P1段；以及一种完全性FTP，即不存在P1段。完全性FTP是否为中风的危险因素应是进一步研究的课题。
