The Spinal Accessory Nerve Anatomy and its role in neck dissections; a review article

Introduction: The purpose of this literature review is to expand our existing knowledge to further understand the innervation of the trapezius muscle, so that new light can be shed which might aid in better outcomes in shoulder function after neck dissections. Methods: A pub med review of the literature revealed 539 articles of which 15 were chosen. Results: Anatomic dissections using cadavers and intraoperative stimulation studies on live patients undergoing neck dissections are presented. Discussion: The Spinal accessory nerve still remains the main nerve supply to the trapezius muscle. Several anatomical details of this nerve are presented. Although cervical plexus provides contributions they are not consistent. A majority of authors agree that during surgical dissections one should avoid removal of any nerve including the branches of the cervical plexus in order to achieve better functional outcomes, and to avoid the disabling shoulder syndrome. Key words: Trapezius, Spinal Accessory nerve, Sternocleido mastoid, Neck dissections