Vertebral artery

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Vertebral artery
Arteries of the neck. The vertebral arteries arise from the subclavian arteries and join to form the basilar artery
Details
SourceSubclavian artery
BranchesBasilar artery
Posterior spinal artery
Anterior spinal artery
Posterior inferior cerebellar artery
VeinVertebral vein
Identifiers
Latinarteria vertebralis
MeSHD014711
TA98A12.2.08.002
TA24538
FMA3956
Anatomical terminology

The vertebral arteries are major arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, midline basilar artery. As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.[1]

Structure

The vertebral arteries usually arise from the posterosuperior aspect of the central subclavian arteries on each side of the body,[2] then enter deep to the transverse process at the level of the 6th cervical vertebrae (C6),[1] or occasionally (in 7.5% of cases) at the level of C7. They then proceed superiorly, in the transverse foramen of each cervical vertebra.[1] Once they have passed through the transverse foramen of C1 (also known as the atlas), the vertebral arteries travel across the posterior arch of C1 and through the suboccipital triangle[citation needed] before entering the foramen magnum.[1]

Nunziante Ippolito, a Neapolitan physician, identified the "angle of Nunziante Ippolito" to find the vertebral artery, between the anterior scalene muscle and the longus colli muscle.[3]

Inside the skull, the two vertebral arteries join to form the basilar artery at the base of the pons. The basilar artery is the main blood supply to the brainstem and connects to the Circle of Willis to potentially supply the rest of the brain if there is compromise to one of the carotids. At each cervical level, the vertebral artery sends branches to the surrounding musculature via the anterior spinal arteries.

Segments of vertebral artery anterior projection

The vertebral artery may be divided into four parts:

Triangle

Triangle of the vertebral artery is a region within the root of the neck and has following boundaries:[4]

The vertebral artery runs from base to apex (prior to entering the transverse foramen of 6th cervical vertebra).[citation needed]

The carotid tubercle separates the vertebral artery which passes directly behind it from the common carotid artery which lies directly in front of it. The ideal site for palpating the carotid pulse is to gently press the common carotid artery against the carotid tubercle.[5]

Variation

There is commonly variations in the course and size of the vertebral arteries, usually on both sides artery diameters are asymmetrical.[6] For example, differences in size between left and right vertebral arteries may range from a slight asymmetry to marked hypoplasia of one side, with studies estimating a prevalence of unilateral vertebral artery hypoplasia between 2% and 25%.[7] In 3-15% of the population, a bony bridge called the arcuate foramen covers the groove for the vertebral artery on vertebra C1. Rarely, the vertebral arteries enter the subarachnoid space at C1-C2 (3%) or C2-C3 (only three cases have been reported) vertebral levels instead of the atlanto-occipital level.[8]

The portion of vertebral arteries located within the skull (intracranial) have diameters of 3.17 mm. The intracranial length for the left vertebral artery (32.4 mm) is longer than the right (31.5 mm). The angle where vertebral arteries meet the basilar artery (vertebrobasilar junction), is 46 degrees.[9]

Vertebral artery dominance

Vertebral artery dominance (VAD) is typically a normal congenital vascular variation of the vertebral arteries. It refers to the asymmetry of the VA diameters on both sides, with the larger diameter being the dominant side and the smaller diameter being the nondominant side.[6]

In one study, the left vertebral artery diameter dominance was present in 54% of cases, while the right diameter was dominant in 30%. In 16% of cases, the left and right arterial diameters were equal.[10]

Function

As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.[1]

Clinical significance

As the supplying component of the vertebrobasilar vascular system, the vertebral arteries supply blood to the upper spinal cord, brainstem, cerebellum, and posterior part of brain.[1] A stroke of the arteries may result in a posterior circulation stroke.[citation needed]

Chiropractic manipulation of the neck has the potential to cause a vertebral arterial dissection.[11][12][13]

Diagnostics

Sagittal section of the right vertebral artery on Doppler ultrasound

The condition and health of the vertebral carotid arteries is usually evaluated using Doppler ultrasound, CT angiography or phase contrast magnetic resonance imaging (PC-MRI).

Typically, blood flow velocities in the carotid artery are measured in terms of peak peak systolic velocity (PSV) and end diastolic velocity (EDV).[14]

Normally, vertebral artery blood flow velocity can be 63.6 ± 17.5 cm/s during PSV and 16.1 ± 5.1 cm/s during EDV according to a study done by Kuhl et al.[15] Due to vertebral artery dominance, measurements can vary on both sides, for example, another study by Seidel et al. found that the right side had an average of 45.9 cm/s and the left side 51.5 cm/s during PSV, and 13.8 cm/s on the right side and 16.1 cm/s on the left side during EDV.[14][16]

Additional images

  • The arteries of the base of the brain (inferior view).
    The arteries of the base of the brain (inferior view).
  • Diagram of the arterial circulation at the base of the brain.
    Diagram of the arterial circulation at the base of the brain.
  • Relationship of the vertebral artery to the suboccipital muscles.
    Relationship of the vertebral artery to the suboccipital muscles.

References

  1. ^ a b c d e f Standing S, Borely NR, Collins P, Crossman AR, Gatzoulis MA, Healy GC, et al. (2008). Gray's Anatomy: The Anatomical Basis of Clinical Practice (40th ed.). London: Churchill Livingstone. ISBN 978-0-8089-2371-8.
  2. ^ Yuan SM (February 2016). "Aberrant Origin of Vertebral Artery and its Clinical Implications". Brazilian Journal of Cardiovascular Surgery. 31 (1): 52–9. doi:10.5935/1678-9741.20150071. PMC 5062690. PMID 27074275.
  3. ^ "Ippolito, Nunziante". Trecanni.
  4. ^ Campero, A.; Rubino, P. A.; Rhoton, L. Jr. (2011). Pathology and surgery around the vertebral artery. Paris: Springer. p. 29. doi:10.1007/978-2-287-89787-0_4. ISBN 978-2-287-89787-0.
  5. ^ Tubbs RS, Salter EG, Wellons JC, Blount JP, Oakes WJ (April 2005). "The triangle of the vertebral artery". Neurosurgery. 56 (suppl. 4): 252–5. doi:10.1227/01.neu.0000156797.07395.15. PMID 15794821. S2CID 10515351.
  6. ^ a b Sun, Yan; Shi, Yan-Min; Xu, Ping (February 3, 2022). "The Clinical Research Progress of Vertebral Artery Dominance and Posterior Circulation Ischemic Stroke". Cerebrovascular Diseases. 51 (5): 553–556. doi:10.1159/000521616. ISSN 1015-9770.
  7. ^ Park JH, Kim JM, Roh JK (September 2007). "Hypoplastic vertebral artery: frequency and associations with ischaemic stroke territory". Journal of Neurology, Neurosurgery, and Psychiatry. 78 (9): 954–8. doi:10.1136/jnnp.2006.105767. PMC 2117863. PMID 17098838.
  8. ^ Moon, Jong Un; Kim, Myoung Soo (September 1, 2019). "C3 segmental vertebral artery diagnosed by computed tomography angiography". Surgical and Radiologic Anatomy. 41 (9): 1075–1078. doi:10.1007/s00276-019-02193-z. ISSN 1279-8517. PMID 30762086. S2CID 61807570.
  9. ^ Omotoso BR, Harrichandparsad R, Satyapal KS, Moodley IG, Lazarus L (June 2021). "Radiological anatomy of the intracranial vertebral artery in a select South African cohort of patients". Scientific Reports. 11 (1): 12138. Bibcode:2021NatSR..1112138O. doi:10.1038/s41598-021-91744-9. PMC 8190432. PMID 34108602.
  10. ^ Cagnie, Barbara; Petrovic, Mirko; Voet, Dirk; Barbaix, Erik; Cambier, Dirk (May 2006). "Vertebral artery dominance and hand preference: Is there a correlation?". Manual Therapy. 11 (2): 153–156. doi:10.1016/j.math.2005.07.005.
  11. ^ Jones, Jeremy; Jones, Catherine; Nugent, Kenneth (January 5, 2015). "Vertebral artery dissection after a chiropractor neck manipulation". Proceedings (Baylor University. Medical Center). 28 (1): 88–90. doi:10.1080/08998280.2015.11929202. PMC 4264725. PMID 25552813.
  12. ^ "Stroke Risk Associated With Aggressive Chiropractic Neck Adjustments". healthblog.uofmhealth.org.
  13. ^ ucsf.edu/news/2003/05/97065/chiropractic-treatment-neck-can-be-risk-factor-stroke
  14. ^ a b Themes, U. F. O. (December 30, 2019). "Ultrasound Assessment of the Vertebral Arteries". Radiology Key. Retrieved March 8, 2024.
  15. ^ Kuhl, V.; Tettenborn, B.; Eicke, B. M.; Visbeck, A.; Meckes, S. (February 4, 2016). "Color-coded duplex ultrasonography of the origin of the vertebral artery: normal values of flow velocities". Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging. 10 (1): 17–21. doi:10.1111/jon200010117. ISSN 1051-2284. PMID 10666977.
  16. ^ Seidel, E.; Eicke, B. M.; Tettenborn, B.; Krummenauer, F. (December 1, 1999). "Reference values for vertebral artery flow volume by duplex sonography in young and elderly adults". Stroke. 30 (12): 2692–2696. doi:10.1161/01.str.30.12.2692. ISSN 0039-2499. PMID 10582999.

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