Unique Case of Aberrant Nerves to Serratus Anterior Muscles with Unusual Branching Pattern of Posterior Cord of Left Brachial Plexus

During the dissection of an 81-year-old male cadaver, interconnected nerve trunks from C6 and C7 to the serratus anterior muscles were revealed bilaterally. These trunks broke up into divisions that gave multiple branches to the muscle; the most inferior of the branches followed the course of long thoracic nerve. In the left axilla, the posterior cord of the brachial plexus gave multiple branches innervating the subscapularis, latissimus dorsi, teres major and teres minor muscles. With exception of the two upper subscapular nerves that originated directly from the posterior cord, the rest arose indirectly from axillary nerve independently and via a common stem. Such variable nerves that occur in multiples carry a potential risk of nerve injury during clinical procedure, which requires awareness and attention to avoid unintended complications as well as to advert their potential use in the treatment of other nerve injuries.