Brachial Plexus, Infraclavicular Exposure

Abstract

The infraclavicular brachial plexus includes the cords and the terminal branches. They correlate closely with the axillary artery. The posterior cord is formed by the junction of the posterior divisions of the three trunks; it first runs lateral and then posterior to the axillary artery. It gives off the thoracodorsal nerve (to latissimus dorsi muscle) and the upper (to subscapularis) and lower subscapular nerves (to subscapularis and teres major muscles). Terminal branches include the axillary and radial nerves. The lateral cord forms from the junction of the anterior divisions of the upper and middle trunks; it first runs anterior then lateral to the axillary artery. It gives off the lateral pectoral nerves. Terminal branches include the musculocutaneous nerve and the lateral contribution to the median nerve. The medial cord is the continuation of the anterior division of the lower trunk; it first runs posterior then medial to the axillary artery. It gives off the medial pectoral nerve, medial brachial cutaneous, and medial antebrachial cutaneous nerves. Terminal branches include the ulnar nerve and the medial contribution to the median nerve.