ANATOMICALVARIATIONS AND ITS CLINICAL SIGNIFICANCE IN VERTEBROBASILAR SYSTEM - A CADAVERIC STUDY IN THE INDIAN POPULATION

Aim: To study the microsurgical anatomy and variations in the vertebrobasilar system of the Indian population and its clinical significance. Materials and Methods: We have studied 40 cadaveric brain specimens in the forensic department at our Coimbatore Medical College Hospital.Microsurgical dissection was carried out and length and diameter of vertebrobasilar artery and its major branches and its associated anomalies were also recorded. Results: The mean diameter of right vertebral artery(VA) was 3.01mm and 3.3mm on the left. Mean angle of fusion is 53o. The diameter of basilar artery ranged from 3-4.7mm (mean 3.9mm) and length varied from 22-41.2mm (mean 35.55mm). No fenestrations or duplication were noted in our study. Variations in VA caliber between both sides were noted. The diameter of the Anterior Inferior Cerebellar artery (AICA) varied from being 0.6-1.42 mm (mean 1.1mm). Superior Cerebellar Artery (SCA) arises very close to basilar bifurcation.No fetal Posterior cerebral artery(PCA) was noted. Conclusion: The understanding of micro vascular anatomy of vertebrobasilar system and its variations is of utmost importance for safe surgery.