First-side loss of signal during planned bilateral thyroidectomy: troubleshooting and intraoperative decision-making

Lee, Sang Joon

doi:2026.6.1.59

J Neuromonit Neurophysiol > Volume 6(1); 2026 > Article

Review Article

Journal of Neuromonitoring & Neurophysiology 2026;6(1):59-69.
DOI: https://doi.org/10.54441/jnn.2026.6.1.59 Published online May 30, 2026.

First-side loss of signal during planned bilateral thyroidectomy: troubleshooting and intraoperative decision-making

Sang Joon Lee

Department of Otorhinolaryngology-Head and Neck Surgery, Dankook University College of Medicine, Cheonan, Republic of Korea

Correspondence: Sang Joon Lee
Email: lsj72@dankook.ac.kr

Received: 2 April 2026 • Revised: 17 April 2026 • Accepted: 17 April 2026

Abstract

Recurrent laryngeal nerve (RLN) injury is a serious complication of thyroid surgery. Intraoperative neural monitoring allows functional assessment of the RLN during dissection, but first-side loss of signal (LOS) during planned bilateral thyroidectomy creates a difficult intraoperative dilemma. Misinterpreting false LOS may lead to unnecessary staged procedures, while overlooking true LOS risks bilateral vocal fold paralysis. This structured narrative review, based on a focused PubMed search (2000-2026), addresses the practical management of first-side LOS in three steps. First, when LOS occurs, the surgeon must systematically exclude false causes such as equipment failure, endotracheal tube malposition, and residual neuromuscular blockade before accepting LOS as genuine. Second, once confirmed, the injury mechanism (traction versus structural), signal loss pattern (segmental versus global), and any intraoperative recovery on continuous monitoring help estimate the likelihood of postoperative vocal fold palsy. Third, in benign bilateral disease, current evidence generally supports staged thyroidectomy as the safest default to avoid bilateral RLN dysfunction. Immediate contralateral completion may still be considered in high-priority situations such as invasive thyroid cancer or impending airway compromise, following individualized risk-benefit assessment. First-side LOS should be treated as a structured decision point, and standardized troubleshooting combined with careful interpretation of monitoring data can support safer and more transparent surgical judgment.

Key Words: Thyroidectomy, Recurrent laryngeal nerve injuries, Intraoperative neurophysiological monitoring, Vocal cord paralysis, Clinical decision-making