Stimulation electromyography as a method of intraoperative identification of the recurrent laryngeal nerve in thyroid surgery.

INTRODUCTION

The iatrogenic injury of the recurrent laryngeal nerve during thyroid surgery still represents a major problem because of the great physiologic and psychologic trauma to the patients. The incidence of this complication ranges between 1% and 15% depending on the thyroid pathology and type of surgery.

AIM: To evaluate the potential of stimulation electromyography as a method of intraoperative prophylaxis of iatrogenic injuries of the recurrent laryngeal nerve.

MATERIAL AND

METHODS

Intraoperative monitoring of the recurrent laryngeal nerve based on stimulation electromyography, which was introduced in the Clinics of Surgery and Otorhinolaryngology at the Higher Medical Institute in Plovdiv, was applied in thyroid surgery using Neurosign 100 (Magstim Company Ltd., Wales, UK) apparatus. The study involved 5 experimental dogs and 73 recurrent laryngeal nerves in 47 patients treated in the clinics from November 1, 1999 to February 15, 2000.

RESULTS

In all experimental animals and patients the electrical stimulation was successful triggering an "M" response of the laryngeal muscles (the vocal muscle). A stable contact was achieved between the recording (needle) electrodes and the vocal folds. None of the patients had signs of laryngeal palsy or complaints other from the usual in endotracheal intubation.

CONCLUSION

The results suggest that the intraoperative stimulation electromyography of the recurrent laryngeal nerve is a safe and effective method for evaluation of the nerve integrity during and at the end of the operation.