Bilateral variant branching pattern of posterior cord of brachial plexus

Abstract

ObjectiveVariant branching pattern of the cords of brachial plexus has been an area of concern for surgeons opting to explore this region. Anaesthetic blocks and surgical approaches are the highlights of these interventions, where a keen familiarization of the anatomy of this region is mandatory. Material and methodsThe present case description reports a bilateral variant branching pattern of the posterior cord in an adult male cadaver. ObservationsRight posterior cord gave upper subscapular nerve and did not give the lower subscapular nerve. Axillary nerve arises proximal to the thoracodorsal nerve. After giving thoracodorsal nerve, posterior cord continued as radial nerve. There is an unusual branch from right axillary nerve, which supplied teres major and sent twig to lower fibres of subscapularis muscle. Left upper subscapular nerve divided into two branches and supplied the subscapularis muscle. Left axillary nerve enclosed by some fibre of subscapularis muscle, within the fibres of subscapularis axillary nerve, gave an unusual branch to teres major and then it continues in quadrangular space. DiscussionIn spite uncountable reports on variations of brachial plexus, descriptions regarding anomalous branching patterns hold enormous clinical significance for the radiologists, anaesthetists and surgeons, besides being of academic interest for the anatomists.