[Intraoperative identification of the recurrent laryngeal nerves in thyroid surgery].

Accidental injury to the recurrent laryngeal nerve is a common complication of thyroid surgery. Different mechanisms of injury have been described, such as mechanical, electrical, or thermal. Retrosternal operations, secondary bleeding requiring wound revision, or neoplastic tumors are also frequent causes of this complication. Intraoperative direct stimulation of suspected nerve structures as well as vagal nerve stimulation have been proposed to avoid the injury. The effect of stimulation can be assessed by direct observation of the vocal cords (direct laryngoscopy or fiberoscopy via a laryngeal mask airway), or electromyography of the posterior cricoarytenoid muscle. All of these methods limit the use of muscle relaxants during anaesthesia. Details of anaesthetic management are presented.