Anatomical Study of Variation of Vertebral Artery Entering the Foramen Transversarium of Cervical Vertebrae

Introduction: The vertebral artery is unique among the cervico-cephalic vessels by virtue of its position and relationship to the adjacent structures. The advent of new techniques and materials for surgical treatment of lower cervical spinal condition has come along with possible potential complications. As vertebral artery normally passes through transverse foramen of sixth cervical vertebra, these procedures can safely be done on seventh cervical vertebra. Aim: To study the anatomical variation of vertebral artery entering the transverse foramen of cervical vertebrae. Material & Methods: 50 vertebral arteries were dissected in 25 embalmed cadavers, out of which 19 cadavers were male and 6 were female. Vertebral artery was dissected from its origin to its entry into foramen magnum. Results: 4 (8 %) cases were found where vertebral artery entered into transverse foramen of 7th cervical vertebrae out of which 1 was bilateral, and 2 was on left side. In 46 cases (92%) it entered through transverse foramen of 6th cervical vertebrae. Conclusion: In 8% cases as vertebral artery enters through C7 transverse foramina, the relation is important while performing transpedicular fixation or other spinal surgeries.