Intraoperative neuromonitoring during thyroidectomy does not decrease vocal cord palsy risk, but the cumulative experience of the surgeon may.

Abstract

Purpose: To evaluate the influence of intraoperative neuromonitoring (IONM) on vocal cord palsy (VCP) rates and assess the temporal trends in VCP rates.

Methods: The subjects of this retrospective study were patients who underwent thyroidectomy for thyroid cancer between March, 2014 and June, 2022, at a university hospital in Korea. We compared VCP rates between the non-IONM and IONM groups and analyzed the risk factors for VCP and VCP rates over time.

Results: A total of 712 patients were included in the analysis. The rates of transient and permanent VCP did not differ significantly between the non-IONM and IONM groups. Transient VCP occurred in 4.6% and 4.3% patients (p = 0.878) and VCP was permanent in 0.7% and 0.4% patients (p = 0.607) in the non-IONM and IONM groups, respectively. Among the nerves at risk, transient damage occurred in 2.8% and 3.0% patients (p = 0.901), and permanent damage occurred in 0.4% and 0.3% (p = 0.688), respectively. Multivariate analysis revealed no significant risk factors for VCP. There was a significant decreasing trend in VCP rates over time as the cumulative number of cases increased (p = 0.017).

Conclusions: IONM did not reduce the risk of VCP significantly. However, the declining trend of VCP rates suggests that the surgeon's experience may mitigate VCP risk.