Thyroid surgery and the usefulness of intraoperative neuromonitoring, a single center study

Purpose/Aim of study: To compare the use of intraoperative neuromonitoring (IONM) versus visualization of the recurrent laryngeal nerve (RLN) alone in thyroid surgery with regard to incidence in postoperative RLN injury and operation time.

This retrospective cohort study was performed in the Amphia Hospital, the Netherlands. All thyroid gland operations were collected from September 2009 to October 2012. For each case we recorded the patient characteristics, indication for surgery, intraoperative data, complications, results of pathological evaluation, and consultation of a ENT-surgeon. Research of current literature and statistical analysis was performed.

In total, 147 patients were included and classified into an IONM and non-IONM group. Both groups were similar in demographical aspects and indications for surgery. In total, we had 170 nerves at risk (NAR). In both groups, there were 85 (50%) NAR. Overall injury to the RLN was 6%. A statistical significant decrease of permanent RLN injuries was noticed in the IONM group compared to the non-IONM group (n = 0 vs n = 6; p = .044). In transient RLN injury, no difference was noticed (n = 2 vs n = 2). Operation time with or without IONM was not significantly different for hemithyroidectomies, neither for total thyroidectomies.

IONM is a useful tool as an adjunct in thyroid surgery to prevent RLN injury. A statistical significant decrease in permanent RLN injury with the use of IONM was found, but it did not significantly decrease time of operation.