Denervation point for neuromuscular blockade on lateral pectoral nerves: a cadaver study

The objective of our study was to clarify the topography of the medial and lateral pectoral nerves (LPNs) and the vascularity in the infraclavicular fossa and to propose an ideal injection point for neuromuscular blockade of the pectoralis major (PM) muscle.

The pectoral muscles and their nerves were examined bilaterally on 10 formalin-fixed cadavers. The PM muscle was dissected from its clavicular origin and sternocostal attachments. It was reflected superolaterally to expose the pectoralis minor muscle and neurovascular bundle at the infraclavicular fossa. We took the measurements to identify a landmark point and reach the neurovascular bundle from an overlying point on the skin.

The LPN was closely related to the thoracoacromial artery and veins on the lower surface of the PM muscle and was visible under the muscle fascia as a neurovascular bundle. The point where the pM line (perpendicular to midsternal line beginning from the inferior border of the jugular notch) transects the neurovascular bundle was sufficiently close to the point at which the neurovascular bundle enters the PM muscle. Hence, this point was determined as the denervation point in all cadaveric dissections. This denervation point is 2.81 ± 0.33 cm distant vertically from the 1/3 medial part of the clavicle and 8.12 ± 1.09 cm distant horizontally from the midsternal line.

We have identified an injection point which may be and suitable and safe location to administer neuromuscular motor blockade of the pectoralis muscles with a percutaneous local anesthetic agent in some clinical pathologies requiring elective denervation.