Anterior Cerebral Artery: An Anatomical Study

Abstract

Introduction: Anterior cerebral artery (ACA), the smaller terminal branch of the internal carotid artery is significant clinically due to its wide variety of complexity and technical difficulty in surgical procedures.Methods and materials: This study was done in 50 embalmed adult brain hemispheres at Institute of Anatomy, Madras Medical College, Tamilnadu. The study of the anterior cerebral artery was undertaken to observe the mode of origin, its course and branches.Results: Anterior cerebral artery originated from the internal carotid artery in 100% of specimens. ACA passed above optic nerve in 32 specimens (64%), above optic chiasma in 16 specimens (32%) and above optic tract in 2 specimens (4%). The average length of A1 segment of right ACA and left ACA were 14.3 mm and 13.7 mm respectively. The difference in diameter of 1mm or more on both sides was observed in 8%. Left A1 segment was duplicated in 1 specimen (2%). Median artery of corpus callosum and Azygous anterior cerebral artery were found in one specimen each. Fenestration of A2 segment was observed in one specimen (4%). Heubner's artery arose from A2 segment in 32 (64%) specimens, from A1 segment in 6 (12%) specimens and from the level of ACoA in 12 (24%) specimens. The orbitofrontal artery originated on an average distance of 5.73mm on right side and average of 4.82mm on left side. Frontopolar artery(FPA) originated at a distance of about 20.2mm on right side and 17.6mm on left side. Callosomarginal artery and pericallosal artery were found in all the specimens. In one specimen the right FPA originated from callosomarginal artery. Conclusion:Rapidly advancing fields of vascular neurosurgery and interventional neuroradiology techniques require a thorough understanding of the anatomy. This detailed study done under various parameters would benefit the radiologists and neurosurgeons.