Microsurgical anatomical study on A1 segment of anterior cerebral artery and its perforating arteries

AIM:To study the microanatomy of A1 segment of anterior cerebral artery(ACA) and its perforating arteries and to provide anatomical data for neurosurgeons.METHODS:Microsurgical anatomy and measurement about ACA and its perforating arteries in 14 cadaveric heads were observed under microscope.RESULTS:Many anatomical variations were found in A1 segment of ACA.Hypoplasia was common in the right A1 segment and the diameter of the left A1 was larger than that of the right A1.Most perforating arteries arose from superior and medial-superior A1 segments and coursed postero-superiorly.A1 segment sent 2-15(mean 8)branches and supplied the anterior perforated substance,basal nuclei,optic chiasm,frontal lobe and hypothalamus.All Heubner recurrent arteries arose from the anterior cerebral artery,usually near the anterior communicating artery.In case of dysplasia at the side of A1 segment,Heubner recurrent arteries could be mixed with the ipsilateral A1 segment.CONCLUSION:Good knowledge of the microsurgical anatomy of the perforating branches of the ACA and good protection of the branches are crucial to prevention of serious operative complications.