Two-stage thyroidectomy in the era of intraoperative neuromonitoring

Background: The use of intraoperative neuromonitoring (IONM) provides surgeons with real time information about recurrent laryngeal nerves (RLN) functional integrity. Hence, allowing them to modify the initially scheduled bilateral procedure, to a two-stage thyroidectomy in cases of loss of signal (LOS) on the first side of resection resulting in minimization of bilateral RLN injury. The purpose of our study was to present our results since the implementation of the above mentioned process in both malignant and benign thyroid disease.

Methods: We conducted a retrospective, observational cohort study of prospectively collected data from all patients who underwent a scheduled total thyroidectomy with or without neck dissection in our Department over the last 4 years [2013-2016]. From the 1,138 patients who received surgical treatment during that period, 284 were excluded since they did not meet the criteria. Exclusion criteria involved previous neck operation, parathyroid surgery, pre-existing vocal cord palsy (VCP) and unilateral surgery. A total of 854 patients were eligible for our study. All patients were subjected to pre- and postoperative indirect laryngoscopy by the same experienced ENT specialist team and all the surgeries were performed by the same experienced team. The whole procedure followed the International Neural Monitoring Study Group's (INMSG) Guideline Statement.

Results: We experienced 70 cases (70/854, 8.2%) with postoperative VCP. Two of them (0.23%) had permanent VCP and the rest of those patients (7.97%) experienced transient VCP. Twenty-three (2.7%) patients were candidates for staged thyroidectomy after LOS on the first side of resection, including ten patients with papillary or medullary thyroid carcinoma and one with toxic multinodular goiter (MNG). Of those patients, 22 incidents of VCP (95.7%) have recovered within two months and one of them persisted for more than six months (permanent VCP). We did not experience any permanent bilateral RLN palsy after the implementation of the staged procedure.

Conclusions: Staged thyroidectomy seems a very attractive and promising procedure for both patient and surgeon, since it nearly eliminates one of the most fearful complications in thyroid surgery. We suggest staged thyroidectomy in all cases with first side of resection signal loss, even in malignancies, since the benefits are much more than the disabilities in a patient's morbidity and quality of life.