Subscapular artery

At a glance

English

Subscapular artery

Latin (TA2)

Arteria subscapularis

System

Artery

Region

Trunk

Side

Paired, left and right

About the subscapular artery

The subscapular artery is the biggest vessel to leave the axillary artery. It springs from the axillary artery in its third part, the segment beyond pectoralis minor, at the point where the artery passes the lower edge of the subscapularis muscle. From there it descends along the lateral (axillary) border of the scapula, keeping close to subscapularis, towards the inferior angle of the shoulder blade.

Only a short distance from its origin, roughly four centimetres, it divides. The first branch is the circumflex scapular artery, which turns backwards through the triangular space to the infraspinous fossa on the back of the scapula. The vessel that continues downwards is the thoracodorsal artery, which joins the thoracodorsal nerve and enters the deep surface of latissimus dorsi; it also sends twigs to serratus anterior and teres major.

Around the scapula the subscapular artery and its branches link up with many neighbouring vessels. Near the inferior angle they communicate with the intercostal and lateral thoracic arteries, and also with the dorsal scapular artery, which runs down the medial border of the bone and may arise from the transverse cervical artery as its deep branch. The circumflex scapular branch joins the suprascapular artery in the infraspinous fossa. Together these channels form the scapular anastomosis.

This anastomosis matters because it connects the subclavian artery, through its thyrocervical trunk and dorsal scapular branch, with the axillary artery beyond pectoralis minor. If the axillary artery is blocked or tied above the subscapular origin, blood can still reach the arm by this collateral route. The thoracodorsal branch is also the pedicle surgeons use when they raise latissimus dorsi as a flap.

Course and supply

Arises from

The axillary artery in its third part, where it crosses the lower edge of subscapularis.

Ends in

Divides into the circumflex scapular and thoracodorsal arteries and ends in the muscles near the lower angle of the shoulder blade, where it meets the dorsal scapular artery in the scapular anastomosis.

Supplies

Supplies subscapularis, latissimus dorsi, teres major, serratus anterior and the muscles on the back of the scapula, and feeds the scapular collateral network.