The surgical anatomy of the brachial plexus.

AIM The brachial plexus (BP) has a complex structure and risky relations with its neighborhoods. This study was designed to investigate and overcome the morphometric features of the BP and the difficulties regarding surgery of BP lesions. MATERIAL AND METHOD Twelve BP of six adult cadavers were dissected and neural structures, branches, and variations were evaluated. Morphometric measurements were done and surgical approaches were discussed. RESULTS The length of anterior (ventral) rami of C5-T1 are in decreasing order such as C5 > C6 > C7 > C8 > T1 and the width of them is in decreasing order such as C7 > C8 > C6 > T1 > C5. The length of upper trunk (UT) , middle trunk (MT) and lower trunk (LT) are approximately similar (UT approximately MT approximately LT) , but the width is in decreasing order as LT > UT > MT. The length of the cords are in decreasing order as posterior cord (PC) > lateral cord (LC) > medial cord (MC), whereas their widths are PC > LC > MC . CONCLUSION From the ventral rami to the cords, BP has a complex and variable anatomic structure. The selection of surgical procedure to the BP needs to be mastered by having the best knowledge of the relevant anatomy.