Anatomy
Arteries are blood vessels that carry blood away from the heart so it can be circulated throughout your body. As they move away from the heart, arteries divide into branches that run off in different directions to reach various structures, including muscles, skin, bones, organs, and other tissues.
Most arteries exist in pairs, with one on each side of the body. Many, but not all, are generally symmetrical.
Structure
The largest artery in the body is the aorta, which runs up away from the heart and then curves back down, creating what’s called the aortic arch. The aortic arch gives off several branches, including the brachiocephalic artery and the left subclavian artery.
Among the brachiocephalic artery’s branches is the right subclavian artery. The first part of each subclavian artery gives rise to the thyrocervical trunk, which then branches off into four main branches:
Inferior thyroid artery Ascending cervical artery Transverse cervical artery Suprascapular artery
The suprascapular artery gives off two main branches:
Suprasternal branchAcromial branch
It also gives off smaller branches to several muscles and a bone.
Location
The thyrocervical trunk gives rise to the suprascapular artery low on the side of your neck. The suprascapular artery runs down and outward (toward your shoulder). Under the sternocleidomastoid muscle, it crosses the anterior scalene muscle and the phrenic nerve on the side of your neck, then crosses the third part of the subclavian artery and the cords of the brachial plexus (a network of nerves in the outer chest that carries movement and sensory signals from the spinal cord to your arms).
The suprascapular artery then runs behind and along the clavicle and subclavius muscle and underneath the omohyoid bone to reach the upper border of the scapula. Crossing the superior transverse ligament, it enters a concave bony structure called the supraspinous fossa, runs down behind the neck of the scapula, through the great scapular notch behind the inferior transverse ligament, and into another concave area—on the back of the shoulder blade—called the infraspinous fossa.
In the infraspinous fossa, the suprascapular artery connects with two other arteries, the scapular circumflex artery and the descending branch of the transverse cervical artery.
The small muscular branches of the suprascapular artery supply blood to the:
Sternocleidomastoid muscle in the neckSubclavius muscle under the clavicleInfraspinatus muscle in your shoulder
The suprasternal branch crosses over the inner tip of the clavicle to supply blood to the skin over the upper portion of your chest.
The acromial branch pierces the trapezius muscle (the large triangular muscle covering the back of your neck, shoulders, and the area between the shoulder blades) to supply the skin over a bony ridge on the top of the scapula called the acromion. There, the suprascapular artery connects to the thoracoacromial artery.
When the suprascapular crosses the superior transverse ligament, it sends out a branch to the subscapular fossa. Further branching out there, it connects to the subscapular artery as well as the transverse cervical artery’s descending branch.
Other branches go to the:
Shoulder joint Acromioclavicular (AC) joint (at the top of your shoulder) Clavicle
Anatomical Variations
Knowledge of the suprascapular artery’s variations is essential for vascular surgeons, orthopedic doctors, and the interpretation of angiograms (X-rays of blood or lymph vessels).
The suprascapular artery doesn’t always arise from the thyrocervical trunk. In rare cases, it’s also known to branch off from:
Subclavian arteryInternal thoracic arteryAxillary arteryAccessory inferior thyroid arterySubscapular arteryCostocervical trunkDorsal scapular artery
In addition, it may take a different route to the suprascapular notch and travel beneath the transverse scapular ligament rather than cross over it. Sometimes these anomalies are limited to one side, while in other cases they may be symmetrical.
At least two cases have been reported in which someone had two suprascapular arteries on each side, with the extra one taking the alternate course beneath the transverse scapular ligament. About 3% of people don’t have a suprascapular artery at all. The artery’s relationship with the suprascapular vein or suprascapular nerve may also vary in some people, sometimes together and sometimes separately.
The suprascapular notch is sometimes much wider and shallower than average, and in these cases it’s especially likely for the suprascapular vein and nerve to lie within the notch.
Function
The suprascapular artery provides blood—meaning oxygen and nutrients—to the muscles, skin, and bones it supplies. That keeps the tissues healthy and allows them to function properly. The muscles supported by the suprascapular artery include:
Sternocleidomastoid muscle (SCM): The SCM runs from the front of your collarbone diagonally along the side of your neck to connect with your skull behind the ear. Its primary function is the side-to-side rotation of your head, bringing your ear to your shoulder and your chin to your chest. It’s also involved in breathing, chewing, and swallowing. Subclavius muscle: This small triangular muscle runs along the underside of the clavicle and connects it to your first rib. It helps make up a group called the anterior axioappendicular muscles (also called the interior wall of the axilla). Infraspinatus muscle: This is a large triangular muscle that’s associated with the rotator cuff. It occupies much of the infraspinatus fossa, and its jobs are to rotate your upper arm and stabilize your shoulder joint.
Clinical Significance
Trauma to the artery anywhere along its course can lead to problems. The shoulder is especially vulnerable to injury and the resulting complications, which can include pseudoaneurysm.
A pseudoaneurysm is the result of an injured blood vessel leaking blood into surrounding tissues. This can cause pain, swelling, and excessive bruising. Some pseudoaneurysms resolve on their own, but others may lead to hemorrhage or other complications if left untreated. Treatment often involves ultrasound-guided injection of an enzyme called thrombin, which helps form blood clots. More invasive surgical procedures may be needed in some cases.
Much of the suprascapular artery’s clinical significance has to do with anatomical variations. Abnormalities involving the artery plus the suprascapular vein and nerve may be associated with some cases of hard-to-diagnose shoulder pain and nerve-related malfunction of the rotator cuff.
The presence of the suprascapular nerve in the suprascapular notch along with the artery may contribute to nerve impingement. Treatment for nerve impingement may include surgical release.
