The significance of persistent trigeminal artery. Carotid-Basilar anastomosis.

Abstract

THE MEDICAL literature contains numerous references citing the coincidence of ersistent trigeminal artery and other cerebrovascular anomalies, the most commonly reported being saccular aneurysm (1–3). Other reports attempt to relate specific clinical syndromes to this morphological variant (4–7). The involution of the trigeminal artery during embryonic development is directly related to the formation of the circle of Willis. When the trigeminal artery is still present postnatally, there is usually hypoplasia or agenesis of the ipsilateral posterior communicating artery (S). Developmental saccular aneurysms are often associated with morphological variation of the circle of Willis (9), and, as one might expect, a saccular aneurysm associated with persistent trigeminal artery is most commonly located on the internal carotid artery where the posterior communicating artery would normally arise. As will be shown in this report, there is little evidence to support a relationship between persistent carotid-basila...