Persistent trigminal artery in the fetus.

Radiological and anatomical studies of a persistent trigeminal artery in three human fetuses are reported. In one fetus there was also an anastomotic artery connecting one of the carotid arteries to the contralateral inferior cerebellar artery. In all three cases, the trigeminal arteries gave branches to the pons. In addition to the pontine branches, one trigeminal artery gave an anastomotic branch to the posterior inferior cerebellar artery and the other trigeminal artery gave branches to both the superior cerebellar artery and the internal auditory artery.