Intraoperative neuromonitoring in thyroidectomy for carcinoma in a high-volume academic hospital.

Background: The diagnosis of thyroid carcinoma has changed in last decades, as the surgical technique during thyroidectomy (endoscopic surgery, robotic surgery, new energy device, intraoperative neuromonitoring).

Methods: We analyzed patients undergone to thyroidectomy or lobectomy for thyroid carcinoma from January 2010 to December 2019 at the General Surgery Unit of the Hospital - University of Parma. We divided patients into two groups, based on the use or not of IONM.

Results: We analyzed data about 638 patients, 486 (76.2%) females and 152 (23.8%) males, with a mean age of 51.8 years. Totally, 574 patients underwent total thyroidectomy and lymphadenectomy was performed in 39 patients. The lobectomy rate was higher in interventions with neuromonitoring (13.93%) than in those without IONM (3.06%). Considering the incidence of postoperative complications and the presence of infiltration of perithyroid tissues or thyroiditis or lymph node metastasis at the histological report, a statistically significant percentage of dysphonia and paraesthesia was recorded only in patients with infiltration of perithyroid tissues (P<0.0001). There was no significant difference in postoperative blood calcium values. The use of intraoperative neuromonitoring has not significantly changed the incidence of postoperative complication.

Conclusions: Our study did not show a protective impact of the use of intraoperative neuromonitoring during thyroidectomy on the incidence of postoperative complications but confirmed that it increases the surgeon's feel safety during surgery and facilitates the identification of any undetected nerve lesion with visually intact nerve, inducing the interruption of the thyroidectomy after lobectomy alone, reducing the risk of bilateral recurrent paralysis.