Persistent trigeminal artery.

Abstract

IN the early fetal life, the internal carotid artery anastomoses with the basilar artery through three vessels (the primitive trigeminal, the otic, and the hypoglossal arteries) all of which usually disappear by the 14-mm stage of the embryo. Up to this stage, the trigeminal artery is a prominent vessel carrying the major supply of blood to the mid-brain and hind-brain. This vessel gradually disappears with the appearance of the stem of the posterior communicating artery at the 14-mm stage. Persistence of the primitive trigeminal artery forming a carotid-basilar anastomosis is rare. Quain 1 first reported the existence of an abnormal communication between the internal carotid and basilar arteries and Padget 2 identified this as persistence of the primitive trigeminal artery. But it was Sutton 3 who first described this carotid-basilar anomaly on angiographic evidence. Prior to Sutton's report, 15 cases were recorded in literature on the basis of autopsy