Thyroidectomy by video assisted neck surgery (VANS) is associated with an elevated risk of recurrent laryngeal nerve injury, especially in the presence of unexpected anatomical abnormalities, such as non-recurrent inferior laryngeal nerve (NRILN), which can be exceedingly difficult to identify and preserve. To reduce the risk of nerve damage, computed tomography (CT) and ultrasonography are useful for preoperative diagnosis, but the number of cases in which anatomical abnormalities can be diagnosed by these modalities is limited. At our department, intraoperative neuromonitoring is performed during all thyroid surgeries, including VANS, in an attempt to reduce the risk of nerve injury.
In this article, we present the case of a 66-year-old female patient in whom intraoperative nerve monitoring during VANS identified a NRILN, which was difficult to diagnose preoperatively, and nerve injury was prevented. The patient was initially started on antithyroid medication to treat Graves’ disease, but the medication had to be discontinued after 2 weeks due to the occurrence of adverse events such as fever, skin rash and liver damage. Therefore, total thyroidectomy was performed by VANS for radical cure. Plain CT and ultrasonography were performed preoperatively, but no anatomical abnormalities could be detected. However, we were able to confirm and preserve a NRILN by intraoperative neuromonitoring using a 4-step procedure to identify the recurrent laryngeal nerve after confirming the vagus nerve. No vocal cord paralysis was observed postoperatively.
Intraoperative neuromonitoring may reduce the risk of unintentional injury of a NRILN during thyroid surgery, including VANS. Therefore, adherence to the 4-step procedure is crucial for identifying and preserving the recurrent laryngeal nerve.
