Overview

Origin. The right subclavian artery arises from the brachiocephalic trunk behind the right sternoclavicular joint. The left arises directly from the aortic arch, behind the left common carotid.

Three parts. Anterior scalene crosses in front of the artery and divides it into three parts. The first part is medial to the muscle and gives the vertebral artery, the internal thoracic artery and the thyrocervical trunk. On the left it also gives the costocervical trunk. The second part lies behind the muscle and, on the right, gives the costocervical trunk. The third part is lateral to the muscle and often gives the dorsal scapular artery.

Relations. The artery lies on the cervical pleura and the apex of the lung, and grooves the first rib behind the scalene tubercle. The trunks of the brachial plexus lie above and behind it. The subclavian vein lies in front of and below it, separated from it by anterior scalene. The right recurrent laryngeal nerve hooks around the right subclavian artery.

Location: Root of the neck, from behind the sternoclavicular joint across the first rib to its lateral border.

Anatomy

Branches: First part: the vertebral artery, internal thoracic artery and thyrocervical trunk (which gives the inferior thyroid, suprascapular and transverse cervical arteries), plus the costocervical trunk on the left. Second part: the costocervical trunk on the right. Third part: the dorsal scapular artery (variable).

Function

Supplies the upper limb, part of the neck, the brain (via the vertebral arteries), the thyroid, the shoulder girdle and the anterior chest wall.

Clinical significance

Thoracic outlet syndrome

The subclavian artery can be compressed by a cervical rib, a fibrous band or the scalene muscles. This can cause arm ischaemia, a dilatation of the artery beyond the narrowing (post-stenotic aneurysm) and emboli to the fingers. Compression of the brachial plexus (neurogenic thoracic outlet syndrome) is more common.

Subclavian steal and haemorrhage control

A stenosis of the first part of the subclavian artery, before the vertebral artery's origin, causes subclavian steal syndrome (see vertebral artery). In a severe arm haemorrhage the artery can be compressed against the first rib by pressing down and backward behind the middle of the clavicle.

Aberrant right subclavian artery

In about 0.5–2% of people the right subclavian artery arises last from the arch (arteria lusoria) and passes behind the oesophagus. It can cause difficulty swallowing (dysphagia lusoria). The right recurrent laryngeal nerve is then "non-recurrent", which surgeons must know about during thyroid surgery.

Mnemonics

Branches

VIT C & D: Vertebral, Internal thoracic, Thyrocervical trunk, Costocervical trunk, Dorsal scapular.

Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.