Human cadaveric study of the morphology of the basilar artery

Nourishment for the brain, a highly vascular organ, is derived from a unique structure called the 'circle of Willis', which is formed by the terminal branches of the internal carotid arteries (ICAs) and basilar arteries (BAs). The circle of Willis forms an anastomotic link between the carotid and vertebrobasilar systems in the arterial supply of the brain, while the BA forms an important component of the brain's posterior circulation and supplies its many vital parts.

A study was performed on 20 brain specimens used for routine dissections at the Anatomy Department, Kasturba Medical College, in order to examine the morphology of BAs in the brain.

In most specimens, the position of the termination of BA was normal, although variations were present in the mode of termination. In one specimen, the BA terminated by dividing into two superior cerebellar arteries. The posterior cerebral arteries (PCAs) arose from ICAs on both sides in this specimen, and a communicating branch was present between the terminal point of the BA and PCA on the left. In another specimen, unilateral variation was seen, with the PCA arising from the ICA on the right and a posterior communicating artery arising from the PCA, connecting it with the BA. The anatomy on the left side was normal.

We highlight the morphological aspects of the BA, the knowledge of which would help neurosurgeons safely diagnose, as well as plan and execute vascular bypass and shunting procedures for the treatment of stenosis, aneurysms and arteriovenous malformations in the posterior cranial fossa.