Denervation point for neuromuscular blockade on lateral pectoral nerves: a cadaver study.
ABSTRACT 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.
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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. Clin. Anat. 25:559–575, 2012. © 2011 Wiley Periodicals, Inc.Clinical Anatomy 07/2012; 25(5):559 - 575. DOI:10.1002/ca.21301 · 1.16 Impact Factor
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ABSTRACT: We present a novel ultrasound-guided regional anaesthetic technique that may achieve complete paraesthesia of the hemithorax. This technique may be a viable alternative to current regional anaesthetic techniques such as thoracic paravertebral and central neuraxial blockade, which can be technically more challenging and have a higher potential side-effect profile. We performed the serratus block at two different levels in the midaxillary line on four female volunteers. We recorded the degree of paraesthesia obtained and performed fat-suppression magnetic resonance imaging and three-dimensional reconstructions of the spread of local anaesthetic in the serratus plane. All volunteers reported an effective block that provided long-lasting paraesthesia (750-840 min). There were no side-effects noted in this initial descriptive study. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for the serratus plane block to provide analgesia following surgery on the thoracic wall. We suggest that this novel approach appears to be safe, effective, and easy to perform, and is associated with a low risk of side-effects.Anaesthesia 08/2013; 68(11). DOI:10.1111/anae.12344 · 3.85 Impact Factor
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ABSTRACT: Subpectoral breast augmentation surgery under regional anesthesia requires the selective neural blockade of the medial and lateral pectoral nerves to diminish postoperative pain syndromes. The purpose of this cadaver study is to demonstrate a reliable ultrasound guided approach to selectively target the pectoral nerves and their branches while sparing the brachial plexus cords. After evaluating the position and appearance of the pectoral nerves in 25 cadavers (50 sides), a portable ultrasound machine was used to guide the injection of 10 ml of 0.2% aqueous methylene blue solution in the pectoral region on both sides of three Thiel's embalmed cadavers using a single entry point-triple injection technique. This technique uses a medial to lateral approach with the entry point just medial to the pectoral minor muscle and three subsequent infiltrations: (1) deep lateral part of the pectoralis minor muscle, (2) between the pectoralis minor and major muscles, and (3) between the pectoralis major muscle and its posterior fascia under ultrasound visualization. Dissection demonstrates that the medial and lateral pectoral nerves were well stained while leaving the brachial plexus cords unstained. We show that 10 ml of an injected solution is sufficient to stain all the medial and lateral pectoral nerve branches without a proximal extension to the cords of the brachial plexus. Clin. Anat. © 2012 Wiley Periodicals, Inc.Clinical Anatomy 01/2013; 26(1). DOI:10.1002/ca.22117 · 1.16 Impact Factor