A study of the formation and branching pattern of brachial plexus and its variations in adult human cadavers of north Karnataka

and Objectives: The brachial plexus is highly variable, in its formation and branching pattern thus, knowledge of its anatomical patterns, may be insufficient for the surgeon operating on or around these nerves or for the regional anesthesiologist working in this area. Therefore, the present study was an attempt to study further about variations of brachial plexus encountered during routine dissection classes. Materials and Methods: The present descriptive study was carried out by dissection of 60 upper limbs of 30 cadavers, in the age group of 18 to 85 years, obtained during a study period of 2 years from the Department of Anatomy. The plexus was studied in its entire course commencing from the formation in cervical region, course through root of the neck and axilla, up to the main terminal branches of the upper extremity. During the dissection, variations of brachial plexus pertaining to its formation from the roots, trunks, divisions and cords and the branching pattern were observed and data was collected. Results: Out of the 60 cadaveric upper limbs studied for the anatomical variations of the brachial plexus, 2 limbs (3.33%) were pre-fixed plexuses. Fusion of adjacent trunks was detected in 2 limbs (3.33%). Variations in branches of lateral cord were detected in 8 limbs (13.33%). Among Posterior cord variations 2-thoracodorsal nerves were detected in 2 limbs (3.33%). All the other branches from brachial plexus had been found to have no anatomical variations. Conclusion: In the present study, an attempt has been made to know the possible variations of the brachial plexus. Though the variations mentioned may not alter the normal functioning of the limb of the individual, but knowledge of the variations is of prime importance to be kept in mind, during anaesthetic and surgical procedures