The value of intraoperative nerve monitoring against recurrent laryngeal nerve injury in thyroid reoperations

Abstract

Reoperative thyroidectomy is challenging for surgeons because of the higher incidence of recurrent laryngeal nerve (RLN) palsy. RLN identification is the gold standard during thyroidectomy; however, it is sometimes difficult to perform thyroid reoperations. In recent years, intraoperative nerve monitoring (IONM) has gained increased acceptance, and the use of IONM can be a valuable adjunct to visual identification. The aim of this study was to evaluate the value of IONM during thyroid reoperation. A total of 109 patients who met our criteria at the Affiliated Hospital of Hangzhou Normal University from January 2010 to June 2020 were retrospectively analyzed and divided into the IONM group and the visualization-alone group (VA group) according to whether neuromonitoring was used during the operation. The patients’ characteristics, perioperative data, and intraoperative information including the RLN identification, time of RLNs confirmation, operative time, intraoperative blood loss, and the rate of RLN injury were collected. Sixty-five procedures (94 RLNs at risk) were performed in the IONM group, whereas 44 (65 RLNs at risk) were in the VA group. The rate of RLN identification was 96.8% in the IONM group and 75.4% in the VA group ( P < .05). The incidence of RLN injury was 5.3% in the IONM group and 13.8% in the VA group ( P > .05). The incidence of surgeon-related RLN injury rate was 0% in the IONM group compared to 7.7% in the VA group ( P < .05), but the tumor-related or scar-related RLN injury rate between the 2 groups were not significantly different (4.3% vs 3.1%, 1.1% vs 3.1%, P > .05). IONM in thyroid reoperation was helpful in improving the RLN identification rate and reducing the surgeon-related RLN injury rate, but was ineffective in reducing the tumor-related and scar-related RLN injury rate. In the future, multicenter prospective studies with large sample sizes may be needed to further assess the role of IONM in thyroid reoperations.

Neuromonitorización rutinaria como herramienta para guiar la extensión de la resección glandular en cirugía tiroidea

“…Se ha observado que también puede resultar ventajosa para la identificación del nervio laríngeo recurrente a nivel transoperatorio. En un estudio retrospectivo realizado por Pei M. et al [14] , en el cual se comparó el uso de la neuromonitorización con la visualización en pacientes durante reintervenciones, su uso presentó un 96.8 % de identificación del nervio laríngeo recurrente en comparación con un 75.4 % en el grupo que exclusivamente utilizó la visualización.…”

Modern Surgical Techniques of Thyroidectomy and Advances in the Prevention and Treatment of Perioperative Complications

“…Intraoperative neuromonitoring (IONM) is a technique for monitoring RLN function by recording the electromyographic signal from the vocal muscle. It assists in localising the RLN, and there are publications reporting that its use results in a reduction in the rate of nerve paralysis during thyroidectomy [148,149]. Therefore, during thyroidectomy, IONM is commonly regarded as an adjunct to the gold standard of the visual identification of the nerve.…”

Intraoperative monitoring of the recurrent laryngeal nerve in thyroid gland surgery

“…A bilateral lesion is thus usually a very severe occurrence, such as requiring a tracheostomy. 1,2,3 The upper laryngeal nerves also innervate the vocal cords; however, they do not determine their movement but rather the degree of muscular tension, thus regulating the high tones of the voice. Their damage determines an inability to use the higher vocal tones, to sing and to use the voice for a long time.…”