Loss of neuromonitoring signal in thyroid surgery: predictive factors and surgical strategies

1- To assess the predictive factors of loss of neuromonitoring signal (LOS) during thyroid surgery and its possible impact on the risk of recurrent laryngeal nerve palsy (RLNP) and 2- to analyze the potential changes in the surgical strategy induced by LOS during surgery. This was a retrospective analysis of the medical records of all patients who underwent hemithyroidectomy (HT) or total thyroidectomy (TT) at our institution between 2005 and 2023. Predictive factors of LOS and RLNP were evaluated via univariate and multivariate analyses. A total of 114 patients (3.4%) experienced unilateral LOS during surgery, and 54 of them developed RLNP (positive predictive value of LOS = 41%). Multivariate analysis revealed that male sex (odds ratio: OR = 2.64; 95% confidence interval: CI = 1.45–4.76) and TT (OR = 1.76; 95% CI = 1.14–2.77) were independently associated with a greater risk of LOS but had no impact on the risk of RLNP. Among the 58 patients who experienced LOS at the end of the first side in a planned TT, surgery was discontinued in 4 patients (4 with postoperative RLNP) and pursued in 48 patients (25 patients with thyroid cancer). TT and male sex were independent risk factors for LOS but were not associated with a higher risk of RLNP in this series. When LOS occurs during a planned TT, the surgeon should consider the risk of true RLN injury and the nature of thyroid disease justifying the removal of the contralateral lobe.