The dorsal scapular artery originates from the posterior scapular artery as a deep branch or as a direct branch of the subclavian artery (3, 4). It runs posteriorly and almost horizontally, deep or through the branches of the brachial plexus. The artery then courses under the trapezius, the omohyoid, and levator scapulae muscles on top of the rib cage. During its course, it gives off branches to these muscles. At the medial angle of the scapula, the dorsal scapular artery gives off a superficial branch that pierces the rhomboid muscle and runs under the deep surface of the lower part of the trapezius; it then gives off one or two cutaneous branches that pierce this muscle and reach the skin.

The anatomic course of this artery must be differentiated from the superficial branch of the posterior scapular artery, which is the main pedicle of the trapezius muscle (5). The dorsal scapular artery runs deep to the levator scapular and the omohyoid muscle; it is not related to the trapezius main pedicle. This is not a conventional lower trapezius flap, which is irrigated by the descending branch of the superficial branch of the posterior scapular artery. The traditional lower trapezius flap disrupts the main vascular pedicle of the trapezius muscle and impairs its function.