RESUMO
The distal medial striated artery, one of the branches of the anterior complex of the circle of Willis, is important because it supplies the caudate nucleus and adjoining putamen, part of the septal nucleus and fibers of the anterior part of the internal capsule. This vessel situated in a region often dealt with in neurological surgeries and can be injured because of its anatomical relationship with important structures in this region. In this study, we examined the anatomical arrangement in 50 human brains fixed in 20 per cent formaldehyde solution. The origin of this vessel was assessed relative to the pre-, post- and communicating segments of the anterior cerebral artery. Of the 121 arteries found, 49.6 per cent arose from the post-communicating segment and were duplicated in 50.4 per cent of the cases, single in 49.6 per cent and symmetrical in 44.5 per cent. The distal medial striated artery was absent in only one specimen. In relation to the pre-communicating segment, the course of this artery was anterior in 77 per cent of the cases, superior in 20 per cent and posterior in 3 per cent. A division of the anterior perforated substance into anterior, lateral and medial regions served to locate the terminal branches of the artery. The terminal branches penetrated the anterior, lateral and medial regions in 48.8 per cent, 47 per cent and 4.3 per cent of the cases respectively.