Acromial anastomosis

The acromial anastomosis (Acromial rete; Acromial network) is an arterial anastomotic network located on the superior surface of the acromion process of the scapula. It is formed by the convergence of the

• Acromial branch of the thoracoacromial artery — the primary contributor, arising from the thoracoacromial trunk (a branch of the second part of the axillary artery). The thoracoacromial artery pierces the clavipectoral fascia and divides into four branches (acromial, clavicular, deltoid, and pectoral), with the acromial branch coursing laterally over the coracoid process to reach the acromion.

• Acromial branch of the suprascapular artery (a branch of the thyrocervical trunk from the subclavian artery).

• Posterior circumflex humeral artery (a branch of the third part of the axillary artery), via its ascending acromial branches.

• Deltoid (ascending) branch of the profunda brachii artery (deep artery of the arm), in some descriptions.

Clinical and Anatomical Significance

This anastomotic network serves as an important collateral vascular pathway around the shoulder region. It provides:

• Collateral circulation to the deltoid muscle, acromion, and surrounding soft tissues, which can maintain perfusion in cases of proximal arterial occlusion or ligation of the axillary artery.

• A vascular supply relevant to surgical approaches to the shoulder, including acromioplasty, rotator cuff repair, and fracture fixation, where knowledge of this network helps minimize bleeding and preserve tissue viability.

• Connections between the subclavian (via the suprascapular artery) and axillary arterial systems, forming part of the broader scapular anastomosis that provides alternative routes of blood flow around the shoulder girdle.

The acromial anastomosis is one of several anastomotic networks around the scapula (along with those on the scapular body and inferior angle) that collectively ensure robust collateral circulation to the upper limb.