A cadaver study on the anatomical variation and branching of the anterior cerebral artery

Abstract

The cortical branches of the distal anterior cerebral artery (ACA) are responsible for the primary blood supply of the corpus callosum. Anatomical variation in these arteries leads to difficulty in defining a standard vascularisation pattern for the distal ACA, which in turn complicates the task of neurovascular surgeons operating on these structures. The particular aim of this study was to investigate the vascularisation of the corpus callosum by studying the anatomical variations and branching of the ACA. The diameter of the ACA at specific landmarks, its course and branches were studied in 34 embalmed brains. The study revealed that the diameter of the distal ACA was the largest (2.46±0.1mm) at the start of the A4-1 segment. At the start of the A4-2 segment, the ACA was significantly smaller (1.61±0.09mm), while being the smallest (1.31±0.1mm) at the start of the A4-3 segment. Therefore, the artery becomes thinner as it proceeds posteriorly over the corpus callosum. In 29.4% of subjects, 4 branches of the A4-2 segment were found to supply the body of the corpus callosum, causing it to be the most vascular portion. The A4-1 segment had 3 branches in 29.4% of subjects, supplying the genu of the corpus callosum. In 38.2% of subjects, 1 supplying branch of the A4-3 segment was found. Although the most supplying branches were expected to be from the A4-1 segment of the distal ACA, the shorter length of this segment, compared to that of the A42 segment, could possibly be the reason for the fewer number of supplying branches. In conclusion, the blood supply of the corpus callosum differs in the various segments of the distal ACA. Knowledge of this vascular anatomy will aid pre-operative planning and avoidance of complications during neurosurgical procedures