Anatomical variations in the posterior portion of the circle of Willis
DOI:
https://doi.org/10.15448/1983-652X.2015.1.17217Keywords:
Circle of Willis. Anatomic variation. Basilar artery.Abstract
Introduction: The brain is vascularized by the internal carotid and vertebral arteries, which form, at the base of the skull, an anastomotic polygon, the cerebral arterial circle (CAC), also known as the circle of Willis. The anatomical variation in the CAC is frequent, many of them being correlated to the occurrence of cerebrovascular diseases.
Objectives: This study aimed at identifying the prevalence of anatomical variations of the arteries of the posterior portion of the CAC based on data obtained from autopsies of cadavers of the Serviço de Verificação de Óbitos, located at Federal University of Paraiba.
Materials and Methods: 30 human cerebral hemispheres of both sexes between 18 and 70 years of age were dissected. Next, the vertebrobasilar and the internal carotid circulation were studied.
Results: There was a rate of 60% of abnormalities in the anatomic posterior cerebral circulation. The cerebral hemisphere more affected was the right one. Anatomical variations were more prevalent in the posterior communicating artery, and the type of anatomical variation that occurred most frequently was hypoplasia.
Conclusion: Knowing the peculiarities of the anatomical variations of CAC is fundamental, due to its high prevalence and its essentiality to understand the emergence of cerebrovascular diseases, such as aneurysms, to perform microvascular reconstructive procedures, as well as to provide essential information on radiological examinations.
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