Anatomical Variations of the Brachial Plexus: A Cadaveric Study

Objective: Variations of the brachial plexus are a lot commoner than presumed and a better understanding of such variations are of crucial importance to achieve successful results in surgical procedures. The aim of our study was to describe the anatomical variations of the brachial plexus in Sri Lankan adult cadavers. Methods: Bilateral upper limbs of cadavers used for routine dissection from January 2023 to September 2024, were examined and the trunks, cords and terminal nerves were described. Images were taken and variations were carefully noted and recorded. Results: Sixty brachial plexuses in 30 cadavers (19 males and 11 females) with a mean age at death of 70.75 years (SD=10.31) were observed. Prevalence of variations was 40%. We report 7 (11.6%) prefixed and 1 postfixed (1.6%) brachial plexuses, variant connections between lateral and medial cords (5 – 8.3%), variant connection between lateral cord and median root of median nerve1(1 - 1.6%), rare variant of only two cords (posterior and combined medial lateral to form an anterior cord), absent musculocutaneous nerve (2 - 2.3%) and musculocutaneous nerve giving a branch to the median nerve (3 – 5%). Conclusion: Variations of the brachial plexus are quite common and highly variable and therefore require constant reporting to provide medical personal with information that could prevent iatrogenic injury and help in proper diagnosis of cases.