A New Variation in the Branching of the Axillary Artery: A Case Report with Surgical Implication

Abstract The axillary artery, situated amid the cords of the brachial plexus, provides branches supplying the shoulder and scapula. It then continues as the brachial artery, typically located posteromedial to the median nerve, which furnishes branches to the arm and elbow. Variations in these branches are not uncommon. However, a dissection of a fixed right upper limb at the Human Anatomy Laboratory of the Federal University of Rio Grande do Norte revealed a remarkable anatomical variation. The researchers discovered an axillary artery that bifurcates into a superficial brachial artery and a posterior trunk. The superficial brachial artery passes over the lateral root of the median nerve and runs superficially to it without giving off any branches. The posterior trunk gives rise to all the branches normally originating from the third part of the axillary artery and the brachial artery, including the subscapular artery, the humeral circumflex arteries, the deep brachial artery, and the collateral ulnar arteries. This unique vascular arrangement has not been previously described in the literature. Awareness of these variations may prevent diagnostic errors, such as misidentifying the superficial brachial artery as a vein, and may influence surgical planning and interventional procedures in the axillary region, including breast cancer surgery or axillary cavity exploration.