The axillary artery high bifurcation: coexisting variants and clinical significance

Several branching patterns of the axillary artery (AA) have been described. Unusually, the brachial artery (BA) follows a course in front of the median nerve (MN), the so-called superficial brachial artery (SBA). The SBA may result in MN entrapment. The current cadaveric report highlights a high AA bifurcation, its continuation as SBA and the coexistence of muscular, neural, and vascular asymmetric aberrations. At the right side, the coracobrachialis muscle (CB) had a single head, and the ipsilateral musculocutaneous nerve (MCN) followed a medial course. The AA was highly divided into superficial and deep stems (SAS and DAS), at the 2nd rib lower border. Between two stems, the brachial plexus (BP) lateral and medial cords were identified. The MN originated from the BP lateral cord. The SAS, continued as SBA with a tortuous course. The DAS coursed posterior to the BP medial and lateral cords and gave off the subscapular artery. A bilateral 3rd head of the biceps brachii was identified. The MN atypically originated from the BP lateral cord. At the left side, the two-headed CB was typically penetrated by the MCN. A common trunk of the circumflex humeral arteries was identified in coexistence with an interconnection of the BP lateral cord with the MN medial root. The rare coexistence of muscular, neural, and arterial variants in axillary and brachial region is emphasized, taking into consideration the AA high division and related branching pattern. Documentation of such rare vascular variants is important in aneurysm and trauma surgery, and angiography, where all therapeutic manipulations must be accurately performed due to the possibility of complications. (Folia Morphol 2024; 83, 1: 200-206)