44 - Anatomical Variation of the Musculocutaneous Nerve: Case Report

Poster Board Number: 44
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Co-authors:

Fernando Luiz Westphal - Universidade Federal do Amazonas; Helder Bindá Pimenta - Universidade do Estado do Amazonas; Gilberto Santos Cerqueira - Universidade Federal do Ceará; Daniela Baptista Frazão - Universidade Federal do Amazonas; Ketholyn Jaqueline Bespalhuk - Universidade do Estado do Amazonas; Camilly Guimarães da Silva Batalha - Universidade do Estado do Amazonas; Ronny helson de Souza Alves - Universidade do Estado do Amazonas; Gabriela Salini Ribeiro - Universidade do Estado do Amazonas; Thiago Soares Martins - Universidade do Estado do Amazonas; Fernando Henrique Lobo Almeida, - UNL; Sabrina Carvalho Chagas - UNL; Gabriel Figueirinha Almeida - UNL; Salete Martens Aurelio - UNL; Ytafaella Oliveira Santana - UNL; Salomon Schuster Biallowons - UNL; Keila Cristiane Batista do Valle - UNL; Maria Carolina Raposo da Câmara Pazuello - UNL; Mateus Lopes Bandeira - UNL; Bernardo Brasil Spies - UNL; Vicente Paulo Afonso Abreu - UNL; Allan Lobato Sant'anna Zakir Matias Padovani da Silva - UNL

Abstract Body : Introduction and objective

The brachial plexus is formed by the union of the ventral rami of the four lower cervical nerves (C5, C6, C7 and C8) and most of the ventral rami of the first thoracic nerve (T1), but frequently, it can receive contributions from the fourth cervical nerve (C4) or second thoracic nerve (T2). These anterior branches form the roots of the plexus: they are almost equal in size but vary in the mode of attachment. The main nerves of the upper limb will emerge through the posterior fascicles, formed by the posterior divisions of the trunks, the lateral fascicle, formed by the anterior divisions of the upper and middle trunks, and the medial fascicle formed by the anterior division of the lower trunk. Therefore, this work aims to describe the anatomical variation of the musculocutaneous nerve relevant to the fields of Anatomy, Anesthesiology, Neurology and Neurosurgery.



Material and methods

This is a descriptive and observational study based on the anatomical dissection of the axillary region to expose the plexus and its terminal branches of an approximately 40-year-old corpse belonging to the collection of the State University of Amazonas (UEA)



Results

In the case study, the lateral fascicle made its contribution to the median nerve and the musculocutaneous nerve (MCN), the latter located on the lateral side of the lower part of the clavicle and the upper edge of the pectoralis minor muscle, the NMC did not pierce the coracobrachialis muscle, sending only one branch to innervate the muscle, characterizing the first anatomical variation. Continuing distally, in the middle third of the arm, a communication was observed between the musculocutaneous nerve and the median nerve, with a distance of 16cm from the coracoid process, thus characterizing the second anatomical variation observed.



Conclusion

We found five individual variations, one of which was bilateral. Some of the findings, variations in the middle and lower trunks, are extremely rare, described only in one other case and in a study of human fetuses. As a result of changes in the origin of the trunks, this had an impact on the origins of the terminal branches.



Implications

wThese changes are of significant importance with regard to procedures in the topography of the root of the neck and axilla, especially in surgeries and anesthetic blocks.