Intraoperative Neuromonitoring in Thyroid Surgery

Abstract

BACKGROUND: Employment of intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) is not unusual nowadays. But up to now, no prospective beneficial studies have been available that evaluate whether the additional use of IONM is beneficial and safe in comparison with conventional thyroid surgery. METHODS: Between 1 August 1999 and 31 January 2001, surgery for benign and malignant goitre was performed on 8900 patients with 16148 nerves at risk. Twenty-eight German hospitals participated. Data were collected prospectively by a questionnaire. Employment of IONM depended on the performing surgeon and was not randomized or controlled. RESULTS: IONM was used in 95.9% (range 57.2–100%) of all thyroid operations. The use of IONM significantly decreased the early RLN palsy rate (3.3% vs. 4.9%; P = 0.04). As for the permanent RLN palsy rate, there was still an advantage gained by using IONM (0.7% vs. 0.9%); however, this difference lacked statistical significance. Overall, IONM was beneficial in high-risk procedures such as recurrent goitre, thyroid carcinoma and extended resections. Employment of the translaryngeal needle electrode of IONM has no influence on general morbidity such as haematomas or wound infections. CONCLUSIONS: The technique of IONM of the RLN in thyroid surgery is safe and decreases the overall RLN palsy rate. IONM in thyroid surgery is especially recommended in high-risk procedures such as recurrent goitre, thyroid carcinoma and extended resections.