Morphology and Variations of the Posterior Cerebral Artery: A Literature Review.

The human brain is supplied by a complex network of vessels, including the circle of Willis (CoW), which provides collateral circulation to ensure optimal perfusion during vascular blockages. An essential component of the CoW is the posterior cerebral artery (PCA), which supplies blood to the occipital lobe, visual cortex, and other cortical brain areas. The PCA typically originates from the bifurcation of the basilar artery but can show variations, such as "fetal-type" PCA. These variations, including hypoplasia, aplasia, duplication, and fenestration, can considerably impact cerebral vasculature and increase the risk of ischemic stroke, aneurysms, and visual impairment. The PCA is divided into multiple segments (P1, P2, P3, P4, and sometimes P5), each with diverse anatomical and morphological variations. Variations in PCA morphology can complicate cerebrovascular management and influence surgical approaches. Understanding these variations is crucial for accurate diagnosis and effective treatment of PCA-related complications. This literature review explores the anatomy of the PCA, including its embryological development, the implications of its variations, and the possible clinical outcomes related to these anomalies.