Anatomy of lateral pectoral nerve and its clinical significance

Background: Anatomy of the pectoral nerves is very important for surgeons who plan pectoral nerve grafts, breast augmentation surgeries, and radical mastectomies. The correlates given in literature are contradictory in nature. Hence, a study was planned to elucidate the anatomy of lateral pectoral nerves (LPNs). Methodology: 40 pectoral regions of embalmed cadavers were dissected. Number, location, length, diameter, branches, and distribution of the LPN were noted. They were grouped according to the number and pattern of origin. Results: Two LPN were found in 77.5% of the specimens, with origins from the lateral cord of brachial plexus either from a common point (45%) or separately (32.5%). Superior LPN (SLPN) was closely related to cephalic vein, had a mean length of 4.7 cm, diameter of 1.9 mm and had two branches supplying clavicular head of pectoralis major. A shorter SLPN of average length 1.55 cm was noted when it pierced the pectoralis minor muscle proximally (32.5%). Inferior LPN (ILPN) was closely related to thoracoacromial vessels, had a mean length of 3.6 cm, diameter 1.7 mm and had two branches, one supplying sternocostal head of pectoralis major and the other communicating with medial pectoral nerve. In 95% of the specimens, both these nerves could be identified just below the clavicle, at the junction between its middle and lateral thirds. In cases with single LPN (7 specimens), it branched into SLPN and ILPN. Conclusion: The anatomy of LPN is variable and important while exploring the pectoral region during surgeries.