| Segments | Extent | Branches |
|---|---|---|
| V1 (Extraosseous) | Each VA arises from the ipsilateral subclavian artery and courses posterosuperiorly to enter the C6 transverse foramen | Unnamed segmental branches |
| V2 (Foraminal) | C6-C1 transverse foramina | Anterior meningeal artery |
| Unnamed segmental branches | ||
| V3 (Extraspinal) | The V3 segment begins after the VA exits the C1 transverse foramen | Posterior meningeal artery |
| V4 (Intradural) | Once the VA becomes intradural, it courses superomedially behind the clivus and in front of the medulla | Anterior & posterior spinal arteries |
| Medullary perforating branches | ||
| Posterior inferior cerebellar artery (PICA) |
Vertebral Artery Anatomy A, aorta; B, basilar artery; C, common carotid artery; SC, subclavian artery; V, vertebral artery. Segments of the path of the vertebral artery; V1, preforaminal; V2, foraminal; V3, atlantoaxial; V4, intradural.
Shafafy R, Suresh S, Afolayan JO, Vaccaro AR, Panchmatia JR. Blunt vertebral vascular injury in trauma patients: ATLS® recommendations and review of current evidence. Journal of Spine Surgery. 2017;3(2):217-225. doi:10.21037/jss.2017.05.10
Vertebral Arteries Defined by 4 Segments Along Their Course: Right vertebral artery with origin from the right subclavian artery. a = artery; br = branch; C = cervical vertebral body; V1, V2, V3, and V4 segments of the vertebral artery.
Novakovic-White R, Corona JM, White JA. Posterior circulation Ischemia in the endovascular era. Neurology. 2021;97(20_Supplement_2). doi:10.1212/wnl.0000000000012808