ABSTRACT
Background: Atherosclerosis of cerebral arteries particularly basilar artery has become common today. Theatherosclerosis of BA can lead to loss of memory, depression and also cerebrovascular accidents. Variations ofthe BA are main cause in the occurrence of cerebrovascular diseases.Context and purpose of study: The knowledge of occurrence of variation of BA can help in early diagnosis andsuccessful surgical intervention. Most of the western studies are mainly based on the radiology. An anatomicalmorphological study of BA and variations will enhance the existing knowledge of BA.Results: The average length of BA is 26.7 mm (with the range of 17.4 mm to 45mm) and the mean diameter is 3.8mm (with the range of 2.1mm to 5.2 mm). The mean angle of formation is 58.6° (with the range between 45° to 70°).In 80% of the specimens the level of formation is normal i.e. at the pontomedullary junction. The position oftermination is normal in 75% of specimens i.e. at the pons midbrain junction.Conclusion: Variations of BA are common both in respect of angle of formation and termination of BA intobranches. Knowledge of the vascular variations will increase the success of the surgical procedures andradiological procedures used in the treatment of vertebro -basilar cerebrovascular pathology.
ABSTRACT
Background: The basilar artery is the large median and major artery of the posterior circulation of the brain. Many variations are seen in the basilar artery, majority of them in position, origin and shape of the artery. Many authors have documented various anomalies as well as differences of the anatomy in this area in the Indian population as compared to the Western literature. Context and purpose of study: Many studies are available on the anterior circulation of the brain i.e. on vessels of the circle of Willis but studies on the posterior circulation are very few. And such studies so far had been done mostly in the American and European races and are mostly based on imaging techniques. Studies in the Indian population have been few. Hence the present study is concentrated on the morphological study of the basilar artery of human adult brain, to show the frequency and type of variations in the morphology of the basilar artery. Results: The basilar artery most commonly takes origin from the vertebral artery where left vertebral artery is greater in size than the right vertebral artery (72.5%). Level of formation of the basilar artery is most commonly observed at the ponto-medullary junction (62.5%). Length of the basilar artery varied from minimum 2.4cm to maximum 3.6cm. More commonly artery lies in the range of 2.6-3.0cm (57.5%). Diameter of the basilar artery at origin ranges from 3.2-4.2mm, at mid level from 3-4mm and at termination 3.1-4mm. Level of termination of the basilar artery is more commonly at the mid brain-pons junction (50%). Most of the basilar arteries are of straight type (55%) and next common is bent or curved type (37.5%). Fenestration of 4mm is seen in proximal part of the one basilar artery (2.5%). Conclusion: Variations of the basilar artery are common. Neurosurgical importance of this study lies during the exposure of the region for different purposes. Knowledge of the vascular variations will increase the success of the surgical procedures and radiological procedures used in interventional radiology.