Accessory Nerve Anatomy in Anterior and Posterior Cervical Triangle: A Fresh Cadaveric Study

Abstract

Objective: To understand the variations and normal course of the accessory nerve (CNXI) to help more accurate and confident neck dissection.Methods: The course of the CNXI in the neck, its relationship to the surrounding anatomic structures and the factors affecting its course were investigated.Results: A total of 100 neck dissections were performed on 50 fresh cadavers. Eleven division variations were observed at the anterior triangle. The location of CNXI at the posterior border of the sternocleidomastoid muscle (PBSCM) was investigated and the ratio between the distance from the mastoid apex (MAA) to CNXI at the PBSCM and the distance from MAA to the posterior border where the PBSCM is attached to the clavicle increased as height of the subject increased (p<0.05).Conclusion: It must be kept in mind that it is better to search for CNXI in taller subjects more inferiorly at the posterior border of the sternocleidomastoid muscle.

Keywords

• accessory nerve
• anatomy
• neck dissection
• erb’s point
• sternocleidomastoid muscle
• injury