A case of vertebral artery duplication at the level of atlas: anatomical description

To present case of vertebral artery duplication surrounding the posterior arch of atlas. The vertebral artery variation was encountered during dissection of specimen from the body of a 62-year-old man. The vertebral artery formed a circle located extraduraly, surrounding the posterior arch of atlas vertebra. Topography and morphometry of the finding is described. Embryology and clinical significance based on literature review are discussed. Precise diagnostic imaging is necessary before surgical interventions at the level of cranio-spinal junction in order to avoid conflict with rare vascular variations.