The persistent trigeminal artery (PTA) represents an important anatomical finding with significant implications for clinical practice, particularly within the field of radiology and neurosurgery.

The persistent trigeminal artery (PTA) is a fascinating anatomical variant that highlights the complexities of cranial vascular development and the importance of thorough anatomical knowledge among medical professionals. As the most common persistent embryonic carotid-basilar anastomosis, the PTA serves as a critical reminder of the vascular structures established during early development, which, in certain individuals, may persist into adulthood. This variant connects the internal carotid artery (ICA) to the basilar artery, generally near the origin of the trigeminal nerve (cranial nerve V). The recognition of the PTA is crucial not only for its anatomical significance but also for its implications in various clinical scenarios.

Understanding the embryological underpinnings of the PTA is vital for appreciating its prevalence and occurrences in the adult population. Normally, in utero, the PTA provides a temporary connection facilitating blood flow during the early stages of development when the vascular system is still forming. As the neural and vascular systems mature, this artery typically undergoes regression, giving way to more permanent vascular connections. However, in approximately 0.1% to 0.6% of the population, this regression does not occur, leading to the persistence of the trigeminal artery as an identifiable structure that can be visualized on imaging studies. 

This discussion aims to provide a comprehensive understanding of the PTA, encompassing its anatomical features, associated clinical conditions, and the implications for diagnosis and treatment planning.