Surgical anatomy of the pectoral nerves and the pectoral musculature

Abstract

The pectoral nerves (PNs) may be selectively injured through various traumatic mechanisms such as direct trauma, hypertrophic muscle compression, and iatrogenic injuries (breast surgery and axillary node dissection, pectoralis major muscle transfers). The PN may be surgically recovered through nerve transfers. They may also be used as donors to the musculocutaneous, axillary, long thoracic, and spinal accessory nerves and for reinnervation of myocutaneous free flaps. Thus, in this article, we reviewed the surgical anatomy of PN. A meta-analysis of the available literature showed that the lateral pectoral nerve (LPN) arises most frequently with two branches from the anterior divisions of the upper and middle trunks (33.8%) or as a single root from the lateral cord (23.4%). The medial pectoral nerve (MPN) usually arises from the medial cord (49.3%), anterior division of the lower trunk (43.8%), or lower trunk (4.7%). The two PN are usually connected immediately distal to the thoracoacromial artery by the so-called ansa pectoralis. The MPN may also show communications with the intercostobrachial nerve. In 50%-100% of cases, it may pass, at least with some branches, through the pectoralis minor muscle. The LPN supplies the upper portions of the pectoralis major muscle; the MPN innervates the lower parts of the pectoralis major and the pectoralis minor muscle. Among the accessory muscles of the pectoral girdle, the LPN may also innervate the tensor semivaginae articulationis humero-scapularis, pectoralis minimus, sternoclavicularis, axillary arch, sternalis, and infraclavicularis muscles; the MPN may innervate the pectoralis quartus, chondrofascialis, axillary arch, chondroepitrochlearis, and sternalis muscles.

The SPA arrangement of the branches of the upper trunk of the brachial plexus: a correction of a longstanding misconception and a new diagram of the brachial plexus

“…3 and 5 in that report). 2 The arrangement of the branches of the UT is incorrectly illustrated in other papers as well, 6,11 and few papers present accurate illustrations. 8,12 Given that a branch may appear several millimeters more proximal or distal, depending on how much of the dissection is car- a. hanna ried out interfascicularly, specific anatomical measurements were intentionally omitted from the current study.…”

Serratus plane block: a novel ultrasound-guided thoracic wall nerve block

“…We used ultrasound in all instances (S-Nerve; SonoSite Iberica S.L, Madrid, Spain), with a linear ultrasound transducer (10)(11)(12). The volunteers were placed in the supine position and the probe was placed over the mid-clavicular region of the thoracic cage in a sagittal plane.…”

“…This revealed two potential spaces, superficial and deep underneath the serratus anterior muscle, between the muscle and the intercostal nerves [8][9][10][11]. Based on these findings, we have developed a new, safe and easily performed regional anaesthetic block.…”

Ultrasound-Guided Continuous Interpectoral Block for Patient Undergoing Mastectomy and Axillary Clearance

“…Thirdly, identification of the lateral border of pmm and the suspensory ligament of the axilla is easier than that in the approach of Blanco (2) Finally, the placement of catheters between PMM and pmm or within the suspensor ligament could be possible with our approach. Continuous interpectoral block provides analgesia to the lateral and medial pectoral nerves combined with several cutaneous branches of the intercostal nerves (11,12). Continuous interpectoral block could become a safe alternative to PVB for breast surgery in some patients when this or other regional techniques cannot be performed.…”