Intramuscular variations in the exit of C5 and C6 roots of the brachial plexus: A case series from Rwanda

Abstract

Background

Anatomical variations in the brachial plexus, particularly the relationship of its roots to the scalene muscles, can significantly impact surgical approaches, nerve blocks, and trauma management. However, such variations are underreported in human cadaveric studies from the East African region in general, and Rwanda in particular.

Objective

This case series documents four distinct variations of the brachial plexus identified during routine cadaveric dissection.

Materials and methods

Forty eight brachial plexus (24 human donors) were dissected using Grant's dissector protocol. All specimens were formalin-fixed and dissected in the anatomy laboratory of the University of Rwanda, with ethical clearance obtained.

Results

Four cases (4/48 = 8.33 %) of intramuscular variation in the exit of C5 and C6 were identified. In case 1, right C5 and C6 roots pierced the anterior scalene muscle instead of passing in the scalenic space. Case 2 showed left C5 piercing the anterior scalene. In case 3 and 4 (bilateral variations in one cadaver), C5 and C6 pierced the anterior scalene on both sides but at different locations. These deviations from the classical interscalene passage may pose risks during surgical or anesthetic procedures.

Conclusion

Anatomical variations of the brachial plexus are not rare and warrant routine consideration during clinical procedures. Preoperative imaging and surgeon awareness are recommended to mitigate iatrogenic risks.