Intraoperative identification of recurrent laryngeal nerves in thyroid surgery by electrical stimulation

Iatrogenic injury of the recurrent laryngeal nerve and its prevention is one of the controversial issues in thyroid surgery. The incidence of this operative complication ranges from 0.4% to 3.9%.

The authors analysed the results of the identification of 114 nerves in 60 patients who underwent thyroid surgery between July 9, 1999 and December 19, 2000 in the 3rd Surgical Clinic at the Department of Clinical Surgery and in the Department of Ear Nose and Throat Diseases of the Medical University in Plovdiv, Bulgaria. Nerve integrity monitor Neurosign 100 and specially designed EMG electrodes (Magstim Company Ltd., Wales, UK) were used. The patients were examined pre- and postoperatively for vocal cord paralysis by otolarygologist.

In all patients electrical stimulation of the recurrent laryngeal nerve was successfully used for identification of the nerve and evaluation of its integrity during and at the end of the operation. No postoperative recurrent laryngeal nerve deficit was detected clinically.

The results indicate that the identification of the recurrent laryngeal nerve by electromyography is a safe, effective and simple method for electrophysiologic monitoring during thyroid surgery. This method allows assessment of the neural integrity at the end of the procedure.