Implementation of Intraoperative Neuromonitoring for Transoral Endoscopic Thyroid Surgery: A Preliminary Report

Abstract

Background: Transoral endoscopic approach is the natural orifice surgery applied in thyroidectomy to achieve an excellent cosmetic result. Recurrent laryngeal nerve (RLN) injury is the most common complication and little advancement was achieved in the previous clinical studies of transoral thyroid surgery. Herein, we introduced the method of intraoperative neuromonitoring (IONM) for transoral endoscopic thyroid surgery.

Materials and methods: Patients with thyroid carcinoma received transoral endoscopic thyroid surgery through vestibular approach (TOETVA) for thyroidectomy and central node dissection (CND). IONM was implemented to identify whether the RLN benefited from oral tracheal intubation. The laryngeal electromyography (EMG) response, operation time, number of CND, drainage volume, hospital duration, surgical complications, and cosmetic results were evaluated.

Results: From August to October 2015, 10 cases were performed with TOETVA and IONM. All EMG responses were recorded intraoperatively, and no case experienced transient or permanent RLN palsy. The operation time ranged from 130 to 215 minutes in ipsilateral lobectomy with CND, whereas bilateral lobectomy with ipsilateral CND lasted 345 minutes. The number of CNDs ranged from three to eight. The average time of drainage extubation and discharge was 4 days (3-5 days) postoperatively. All patients were satisfied with the cosmetic results, and no infection was observed at lip wound or in the anterior neck region.

Conclusion: IONM system implemented in transoral thyroid surgery was feasible and serviceable in preventing RLN injury. The method of TOETVA shows promise for thyroidectomy with CND due its ideal cosmetic results.

Keywords: endoscopic surgery; neural monitoring; thyroid carcinoma; vestibular approach.