The vertebral artery (artery, from the Latin arteria, from the Greek artêria, vertebra, from the Latin vertebra, from vertere) ensures the supply of oxygenated blood to the brain.

Position. Two in number, the left and right vertebral arteries are located in the neck and head.

Size. The vertebral arteries have an average caliber of 3 to 4 mm. They often present an asymmetry: the left vertebral artery generally has a larger caliber than the right vertebral artery. (1)

Origin. The vertebral artery originates on the upper face of the trunk of the subclavian artery, and constitutes the first collateral branch of the latter. (1)

Path. The vertebral artery travels up the neck to join the head. It borrows the transverse canal, formed by the stacking of the cervical vertebrae. Arriving at the level of the first cervical vertebra, it crosses the foramen magnum, or occipital foramen, to join the posterior part of the brain. (2)

Termination. The two vertebral arteries are found at the level of the brainstem, and more particularly at the level of the groove between the bridge and the medulla oblongata. They unite to form the basilar artery or trunk. (2)

Branches of the vertebral artery. Along its path, the vertebral artery gives rise to many more or less important branches. We distinguish in particular (3):

• The dorso-spinal branches, which arise at the level of the cervical vertebrae;
• The anterior and posterior spinal arteries, which originate in the intracranial part.

Irrigation. The vertebral arteries then the basilar trunk play an essential role in the vascularization of the various structures of the brain.

Dissection of the vertebral artery is a pathology that corresponds to the appearance and development of hematomas within the vertebral artery. Depending on the position of these hematomas, the caliber of the artery may then be narrowed or distended.

• If the caliber of the vertebral artery is narrowed, it can become blocked. This causes a decrease or even a stop of the vascularization, and can lead to an ischemic attack.
• If the caliber of the vertebral artery is distended, it can compress neighboring structures. In some cases, the wall of the artery can rupture and cause a hemorrhagic accident. These ischemic and hemorrhagic attacks constitute cerebrovascular accidents. (4) (5)
• Thrombosis. This pathology corresponds to the formation of a blood clot in a blood vessel. When this pathology affects an artery, it is called arterial thrombosis. (5)

Arterial hypertension. This pathology corresponds to an excessive pressure of the blood against the walls of the arteries, occurring in particular at the level of the femoral artery. It can increase the risk of vascular disease. (6)

Drug treatments. Depending on the condition diagnosed, certain drugs may be prescribed to lower blood pressure.

Thrombolyse. Used during strokes, this treatment consists of breaking up the thrombi, or blood clots, with the help of drugs. (5)

Surgical treatment. Depending on the pathology diagnosed and its evolution, surgery may be necessary.

Physical examination. First, a clinical examination is carried out in order to identify and assess the pain perceived by the patient.

Medical imaging exams. In order to confirm or deepen a diagnosis, X-ray, CT, CT angiography and arteriography examinations can be performed.

• Doppler ultrasound. This specific ultrasound makes it possible to observe the blood flow.

The vertebral artery is subject to different anatomical variations, particularly on its point of origin. It generally originates on the upper surface of the trunk of the subclavian artery but it happens that it originates downstream to become the second collateral branch of the subclavian artery, after the thyrocervical trunk. It can also arise upstream. For example, the left vertebral artery emerges from the aortic arch in 5% of individuals. (1) (2)