Bilateral multiple complex variations in the formation and branching pattern of brachial plexus

Area of Science:

• Anatomy
• Morphology

Background:

• The brachial plexus exhibits typical formation and branching patterns.
• Bilateral variations in brachial plexus anatomy are exceptionally rare.

Purpose of the Study:

• To document and describe multiple, simultaneous bilateral variations in the brachial plexus.
• To emphasize the clinical significance of understanding such rare anatomical anomalies.

Main Methods:

• Cadaveric dissection of an adult male.
• Detailed observation and documentation of brachial plexus formation, divisions, trunks, cords, and branching patterns.

Main Results:

• Observed significant bilateral deviations in lateral and medial cord formation.
• Identified anomalous origins for multiple nerves, including two lateral roots, two medial roots of the median nerve (left side), and varying numbers of upper subscapular nerves.
• Noted unusual branching patterns of the anterior division of the middle trunk.

Conclusions:

• The simultaneous occurrence of numerous bilateral brachial plexus variations is highly uncommon.
• Awareness of these anatomical variations is crucial for accurate diagnosis and safe execution of surgical procedures and nerve blocks in the neck and proximal arm.