Vertebral artery variations revised: origin, course, branches and embryonic development

Abstract

Background: The vertebral artery originates from the subclavian artery and is divided into four segments. The aim of this study is to investigate the anatomical variations in the course and branches of the vertebral artery. Materials and methods: A research was performed via Pubmed database, using the terms; "variations of vertebral artery AND cadaveric study", "variations of vertebral artery AND cadavers" and "anomalies of vertebral artery AND cadavers". Results: A total of 24 articles met the inclusion criteria, 13 of them referring to variations of the origin of the vertebral artery, 9 to variations of the course and 3 to variations of its branches. On a total sample of 1192 cadavers of different population, origin of the left vertebral artery directly from the aortic arch was observed at 6.7%. In addition, among 311 cadavers, 17.4% were found with partially or fully ossified foramen of the atlas for the passage of the vertebral artery, while the bibliographic review also showed variants at the exit site of the artery from the transverse foramen of the axis. Conclusions: Despite the fact that variations of both the course and the branches of vertebral artery are in most cases asymptomatic, good knowledge of anatomy and its variants is of particular importance for the prevention of vascular complications during surgical and radiological procedures in the cervix area.

Are Strokes Mostly Genetically Based or Acquired? Stenosis vs Hypoplasia of Vertebral Artery Anomalous as The Leading Cause of Stroke (Anatomical Study of VA Anomalies in Neck Three-Dimensional Computed Tomography Angiography)

“…Extradural origins of VA, similar to our ndings, were reported in about 4% of patients through previous studies [20]. PICA termination is widespread in cases of left VA origin from the aortic arch, and the extradural branches of VA should be taken into consideration [13].…”

“…With advances in interventional radiology and surgical methods in the neck, a thorough knowledge of VA's anatomical variations regarding its origin, course, and branches is crucial to minimize procedurerelated complications [13]. Although colour Doppler ultrasonography has been traditionally considered the primary diagnostic modality in VA variations, CTA and MR angiography more accurately depict these variations and anomalies [14].…”

Clinical Importance of the Posterior Inferior Cerebellar Artery: A Review of the Literature

“…An extradural origin PICA from the VA is not rare. The frequency of an extradural origin of the PICA ranges from 0.4% to 20.8% 1 , 4 , 12 , 18 , 19 , 22 - 25 . The extradurally located PICAs are exposed to injury during posterior approaches to the lower brainstem and upper cervical spine.…”

Vertebral Artery Variations at the Craniovertebral Junction in “Sandwich” Atlantoaxial Dislocation Patients

“…A normal VA is divided into 4 segments: V1 segment (It originates from the subclavical artery and enters the C6 transverse process), V2 segment (walks through C6-2 transverse process), V3 segment (the segment courses from C2 to the foramen magnum), and V4 segment is coursing from entering the cranium to attending the basilar artery. 9 Wang et al 10 has previously reported anatomical V3 segment variations of VA in patients with atlas occipitalization. The bone deformity of "sandwich" AAD patients was more serious than mere atlas occipitalization, and the combined VA deformities may be more complex, which have not been reported yet.…”