Use of the laryngeal mask airway in thyroid and parathyroid surgery as an aid to the identification and preservation of the recurrent laryngeal nerves

A prospective study was carried out in patients undergoing thyroid and para thyroid surgery using a laryngeal mask airway (LMA) and electrical nerve st imulation to identify the recurrent laryngeal nerves. A total of 150 consec utive patients undergoing thyroid and parathyroid surgery by a single surge on were assessed for suitability of anaesthesia via the LMA. Peroperatively , a fibre-optic laryngoscope was passed through the LMA to enable the anaes thetist to visualise the vocal cords while adduction of the cords was elici ted by applying a nerve stimulator in the operative field. In all, 144 pati ents were selected for anaesthesia via the LMA. Fibre-optic laryngoscopy an d nerve stimulation were performed in 64 patients (42.7%). The trachea was deviated in 51 (34.0%) and narrowed in 33 (22.0%). The recurrent laryngeal nerves were identified in all patients. There were no cases of vocal cord d ysfunction resulting from surgery. The LMA can be safely used for thyroid a nd parathyroid surgery even in the presence of a deviated or narrowed trach ea. It can assist in identification and preservation of the recurrent laryn geal nerve and is, therefore, of benefit to both patient and surgeon.