Abstract
On the basis of 100 brachial plexus dissections in adult subjects, the angular variations of roots in their intrarachidian and cervical portions are examined. Serial histological sections of 21 brachial plexuses allow one to define fascicular histologic organization. These descriptions of biometric anatomical variation and complexity in histological fascicular organization help to elucidate the difficulties that must be overcome following nerve suture in order to achieve a satisfactory functional recovery.