Considering the spinal accessory nerve in head and neck surgery

Loss of trapezius muscle function represents the single most important source of long-term morbidity from a radical neck dissection. Its preservation has been one of the central features of the conservative or modified neck dissection. We recently undertook an evaluation of 100 consecutive patients who had undergone composite resection for head and neck cancer and examined them with particular emphasis on the function of the trapezius muscle. The mean interval from the time of radical neck dissection to the time of this evaluation was 6.2 years. The operations included radical neck dissection with sacrifice of the spinal accessory nerve, radical neck dissection with preservation of the spinal accessory nerve, and radical neck dissection with interpositioned cable graft reconstruction. The survey showed that 67 percent of the patients who underwent radical neck dissection with sacrifice of the spinal accessory nerve, although they showed profound atrophy of the trapezius muscle, had few symptoms related to this deficit. Similarly, 47 percent of patients who underwent radical neck dissection with preservation of the spinal accessory nerve showed some signs of muscle atrophy, and 20 percent showed little or no function of the muscle. Interpositioned nerve grafts appeared to function well in 66 percent of the patients. The survey showed that a surprising number of patients treated with a standard radical neck dissection and sacrifice of the spinal accessory nerve had few postoperative symptoms related to the loss of trapezius muscle function. Also unexpected was the number of patients with signs of muscle dysfunction despite nerve preservation.