The anatomy of the accessory nerve and cervical lymph node biopsy.

Injury to the accessory nerve is the most frequent complication of surgical procedures in the posterior triangle of the neck. The symptoms produced by paralysis of the trapezius are disabling. The components of this disability are pain, limitation of abduction, and drooping of the affected shoulder. A detailed knowledge of the course of the nerve and its anatomic relations are essential in avoiding injury. Useful anatomic landmarks are the proximal internal jugular vein in the anterior triangle and Erb's point in the posterior triangle. Prevention of accessory nerve injury is the best management. The indications for lymph node biopsies in the neck should be sound. The use of a general anesthetic without paralysis is recommended if an excisional biopsy is necessary. Adequate exposure is essential. Whether the nerve needs to be identified in all cases has to be individualized and requires careful judgment. A divided or injured nerve is best managed with primary repair within 3 months of injury.