Usefulness of neuromonitoring in thyroid surgery

One of the most important complications during thyroid surgery is injury to the recurrent laryngeal nerve (RLN) which leads to dysfunction and palsy of the vocal folds. Adequate knowledge about the location of the RLN supported by neuromonitoring can help the operating surgeon to prevent this complication. Visualization of the nerve alone seems not enough. An estimation of the function of the RLN is very important. Recently, the use of neuromonitoring has been increasingly employed to predict and document nerve function at the end of thyroidectomy. The aim of the study was to verify the usefulness of neuromonitoring in identifying the recurrent laryngeal nerve and to predict postoperative outcome in patients undergoing thyroid surgery for different indications. Between March 2009 and October 2010, 91 patients (26 men, 65 women; mean age 53 (range 26-83) underwent thyroidectomy. Intraoperative neuromonitoring (IONM) was registered for 91 patients. Eighty-four total thyroidectomies and seven lobectomies were performed with IONM. Eight unilateral postoperative transient paresis were identified without any permanent paralysis. Intraoperative neuromonitoring has an excellent specificity and negative predictive value in which an unchanged positive signal is highly predictive of intact nerve function. Intraoperative neuromonitoring during thyroid surgery is a reliable tool for early recurrent laryngeal nerve localization and identification, certainly in complicated thyroid operations. The probability is high for correctly predicting an intact postoperative nerve function by neuromonitoring.