ABSTRACT
The posterior triangle of the neck contains the spinal accessory nerve (SAN), phrenic nerve (C3, 4, 5) and branches of the cervical plexus and the supraclavicular brachial plexus with its proximal branches. The apical pleura and lung extend upwards behind the first rib, and the proximal subclavian artery and vein pass anterior to it. This concentration of vital structures is a common site for severe, even life-threatening, injuries from knife, missile or severe traction, and also for clinical mishaps during blocks, infusions or operations for benign lesions.
