Variations in the brain circulation – the circle of Willis

Background Knowledge of the variations of vascular anatomy of Circle of Willis will guide the neurosurgeons during intracranial surgery. Objectives: The aim of our study is to analyze the variations regarding shape, symmetry, length and diameters of the component arteries. The study also includes other variations like absence, duplication and abnormal origin of component arteries. Methods: In the present study 31 specimens of human brains are obtained from the Department of Anatomy IIMSR Warudi, Badnapur, Dist. Jalna. Careful observation & measurement of the component arteries are done after proper preservation and necessary dissection. The findings are then recorded and analyzed. Results: There were 21 out of 31 specimens (67.74%) found to be classic form of ‘Circle of Willis’, that was, complete, symmetrical, normal caliber and heptagonal in shape. These 21 specimens have, therefore, been considered as ‘Normal’. The rest 10 specimens (33.5%) of human brain were shows variations. Conclusion: Out of 33.5% variations most of the variations are seen in posterior communicating artery 3.22%, followed by anterior cerebral artery (6.45%) and anterior communicating artery (6.45%). Most common type of variation is hypoplasia. Keyword: ‘Circle of Willis cerebral arteries, Arterial variation, Internal Carotid Artery, Vertebral Artery, Hypoplasia