Thoracoacromialis

The thoracoacromial trunk, also known as truncus thoracoacromialis, is a short arterial trunk that arises from the second part of the axillary artery, typically medial to the pectoralis minor. It courses anterior to the upper chest and shoulder region before dividing into four branches: pectoral, clavicular, acromial, and deltoid.

The pectoral branch descends between the pectoralis major and minor to supply these muscles and adjacent chest wall structures. The clavicular branch runs toward the subclavius muscle and the sternoclavicular joint. The acromial branch travels toward the acromion and shoulder region, contributing to the vascular supply of the deltoid area and surrounding tissues. The deltoid branch provides blood to the deltoid muscle.

These branches form an interconnected network with other arteries of the thoracic wall and shoulder, including contributions from the lateral thoracic artery and perforating arteries of the intercostal spaces, creating important collateral pathways.

Clinically, the thoracoacromial trunk serves as a useful anatomical landmark in axillary and shoulder region surgeries and imaging. Variations may occur, such as an absent distinct trunk with direct branching from the axillary artery, or alterations in branch pattern. Understanding its course and branches aids in procedures involving the pectoral region, shoulder, and related reconstructive interventions.