Deep brachial artery

The deep brachial artery (Profunda brachii artery; Deep artery of arm) is the first and largest branch of the brachial artery. It originates from the posterior aspect of the brachial artery, typically near the level of the inferior border of the teres major muscle, close to the insertion of the latissimus dorsi tendon.

Course and Relations

The deep brachial artery accompanies the radial nerve through the radial (spiral) groove on the posterior surface of the humerus, passing between the medial and lateral heads of the triceps brachii muscle. Along its course, the radial nerve is flanked not by a single vessel but by two branches resulting from the bifurcation of the deep brachial artery — an anterior branch (traveling toward the triceps medial head) and a posterior branch (coursing around the humerus lateral to the radial nerve).

Branches and Termination

The deep brachial artery gives off the following branches before terminating:

• Middle collateral artery — supplies the posterolateral arm and contributes to the anastomotic network around the elbow

• Radial collateral artery, which bifurcates into the anterior radial collateral artery (ARCA) and the posterior radial collateral artery (PRCA) — these participate in the periarticular anastomosis of the elbow

The middle collateral artery anastomoses with the inferior ulnar collateral artery, forming part of the collateral circulation around the elbow joint.

Anatomical Variations

The deep brachial artery originates directly from the brachial or axillary artery in approximately 92.9% of cases, while in about 7.1% it arises indirectly as a common trunk with other arteries (e.g., the subscapular artery or posterior circumflex humeral artery). Its mean diameter is approximately 2.05 mm. In rare cases (~8.4%), the posterior circumflex humeral artery may originate from the deep brachial artery rather than from the axillary artery.

Clinical Significance

Knowledge of the deep brachial artery's anatomy is essential during surgical dissection of the radial nerve (e.g., in brachial plexus reconstruction, radial nerve repair, or fracture fixation of the humeral shaft), as the artery is in intimate contact with the nerve throughout its course in the radial groove. The deep brachial artery also serves as the vascular pedicle for the lateral arm flap and its extended variant (the "extreme" lateral arm flap), used in reconstructive surgery.