Rare variations in the branching pattern of the axillary artery: a cadaveric case report

This case report investigates a rare variation of the axillary artery (AA) where most AA branches arose from a variant branch (VB) originating from the second part of the AA. It hopes to enhance the accuracy of surgical procedures on the upper limb and contribute to a more comprehensive understanding of AA anatomy.

An Asian female cadaver was dissected, and the unique branching patterns of the AA was documented by photograph and illustration. The external diameter and the origin of the AA branches to the thoracoacromial artery (TAA) was measured by digital caliper.

The VB originated from the AA at the level of the TAA, giving rise to the anterior and posterior circumflex humeral arteries (ACHA and PCHA). Additionally, the VB gave off a common trunk that branched into the circumflex scapular artery (CSA) and continued as the subscapular artery (SSA),which then divided into the lateral thoracic artery (LTA) and thoracodorsal artery (TDA). The VB had two terminal branches: the posterior terminal branch (PTB) coursing through the radial nerve tunnel, and the anterior terminal branch (ATB) descending along the inner side of the arm, passing through the medial side of the elbow, and supplying the forearm.

The variants of the AA could be useful in surgical procedures that involve the lateral thorax, axilla and arm, contributing to a broader anatomical knowledge essential for radiographic, surgical, and other interventional procedures of the upper limb.