Superficial location of the brachial plexus and axillary artery in relation to pectoralis minor: a case report

Knowledge of the anatomy of the infraclavicular fossa is important as this region is a target site for anaesthesia of the upper limb during infraclavicular approaches to brachial plexus blocks and in central venous cannulation of the axillary or subclavian veins. The cords of the brachial plexus and the axillary artery and vein are classically described as being located deep to the pectoralis minor and major muscles in the infraclavicular fossa. A rare variation was observed on one side of an individual, out of a total of 170 dissections, in which the brachial plexus and axillary artery were located between the pectoralis minor and major muscles. This variation was observed on the right-hand side of a male cadaver, and resulted in a more superficial position of the cords of the brachial plexus and axillary artery in relation to the skin. This superficial position of these vital structures may lead to an increased risk of complications during clinical procedures, such as infraclavicular brachial plexus blocks, central venous cannulation or surgery. Ultrasound should be used whenever possible to visualise variant positions of arteries, veins, nerves or muscles during these and other procedures.Keywords: anatomical variation, axillary artery, brachial plexus, infraclavicular region, pectoralis mino