title: A case of vertebral artery duplication at the level of atlas: anatomical description.
abstract: OBJECTIVE
  To present case of vertebral artery duplication surrounding the posterior arch of atlas.
  
  
  METHODS
  The vertebral artery variation was encountered during dissection of specimen from the body of a 62-year-old man.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Precise diagnostic imaging is necessary before surgical interventions at the level of cranio-spinal junction in order to avoid conflict with rare vascular variations.
authors.affiliation: Department of Descriptive and Clinical Anatomy, Centre of Biostructure Research, Medical University of Warsaw, Chałubińskiego 5, 02-004, Warsaw, Poland, maciej.ciolkowski@wum.edu.pl.
authors.forename: Maciej K
authors.initials: MK
authors.lastname: Ciołkowski
authors.forename: Paweł
authors.initials: P
authors.lastname: Krajewski
authors.forename: Bogdan
authors.initials: B
authors.lastname: Ciszek
mesh_terms: D001270:Cervical Atlas; D006801:Humans; D008297:Male; D008875:Middle Aged; D014711:Vertebral Artery / Q000002:abnormalities*
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