Prospective analysis of the efficacy of continuous intraoperative nerve monitoring during thyroidectomy, parathyroidectomy, and parotidectomy

Abstract

Objective: Continuous intraoperative electromyographic monitoring was prospectively performed in all parotidectomies, thyroidectomies, and parathyroidectomies over approximatelsy 5 years to assess the efficacy of this technology. Study Design and Setting: Continuous intraoperative nerve monitoring with perioperative nerve assessment was performed. The postresection minimal stimulation level of the nerves was determined to evaluate if this level would predict nerve function postoperatively. Results: Forty-four parotidectomies and 70 thyroid/parathyroid operations were performed with 140 nerves at risk (44 facial, 96 recurrent laryngeal). The incidence of temporary facial paralysis was 15.9% (7 of 44) and the incidence of permanent paralysis was 0%. The incidence of temporary recurrent laryngeal nerve paralysis in terms of nerves at risk was 1.0% (1 of 96), and the incidence of permanent recurrent laryngeal nerve paralysis was 0%. All patients with normally functioning facial and recurrent laryngeal nerves postoperatively had minimal stimulation levels less than or equal to 0.4 mA. Conclusion: Continuous intraoperative nerve monitoring was associated with extremely low rates of temporary and permanent nerve paralysis in our series of 140 nerves at risk as compared to the rates documented in the literature. (Otolaryngol Head Neck Surg 2001;124:537-43.)