Accessory nerve function after modified radical and lateral neck dissections

Objectives: Evaluate preoperative and postoperative electrophysiological ch anges related to the accessory nerve with reference to dissection technique , modified radical neck dissection, and lateral neck dissection, Study Desi gn: Prospective electrophysiological analysis of accessory nerve function i n a total of 20 laryngeal carcinoma patients after neck dissection, 12 bein g lateral neck dissection (4 bilateral) and 8 being modified radical neck d issection. Methods: Distal latencies, compound muscle action potentials, an d electromyography findings were investigated before surgery and, in early and late postoperative periods in 20 laryngeal carcinoma patients. Results were evaluated by Student t test and chi(2) test for intragroup and intergr oup differences. Results: In the lateral neck dissection group, postoperati ve distal latencies were longer, without statistical significance, whereas in the modified radical neck dissection group postoperative latencies were statistically longer. Postoperative compound muscle action potentials were significantly lower in both groups. Electromyographic work-up showed deteri oration in early postoperative periods and improvement in late postoperativ e periods, When intergroup differences were compared, both postoperative co mpound muscle action potential and electromyographic findings were worse in the lateral neck dissection group, Conclusions: The accessory nerve functi on after modified radical neck. dissection is better than function after la teral neck. dissection because of increased stress applied to the nerve dur ing retraction of the sternocleidomastoid muscle for achievement of a bette r exposed surgical field in lateral neck dissection.