THE NEUROVASCULAR RELATIONSHIPS AND THE BLOOD-SUPPLY OF THE ABDUCENT NERVE - SURGICAL ANATOMY OF ITS CISTERNAL SEGMENT

TWENTY-EIGHT ABDUCENT NERVES were examined after injecting india ink a nd gelatin into the vertebrobasilar arterial system. All the abducent nerves were found to be crossed and/or penetrated by the surrounding v essels. The ventral surface of the nerves was crossed by the anterior inferior cerebellar artery (AICA) (75.0%), the posterior inferior cere bellar artery (17.85%), the common trunk of the AICA and posterior inf erior cerebellar artery (7.14%), the internal auditory artery (14.28%) , the anterolateral artery (46.43%), the pontomedullary artery (92.86% ), and the corresponding veins (46.43%). The dorsal surface of the cis ternal segment was crossed by the AICA (35.71%), the inferolateral pon tine artery (10.71%), the anterolateral artery (82.14%), and the certa in veins (46.43%). Sixty-four percent of the cisternal segments were p enetrated by one or more of the following vessels: the AICA (25.0%), t he anterolateral artery (17.86%), the pontomedullary artery (3.57%), a nd/or by the corresponding: veins (42.86%). The majority of the cister nal segments of the abducent nerves were supplied by the anterolateral arteries (85.71%), and only some of them by the AICA (14.29%) or the pontomedullary artery (7.14%), The authors discuss the possible clinic al significance of the anatomical data.