Comparative Analysis of the Effectiveness of Recurrent Laryngeal Nerve Neuromonitoring Using Paired Intramuscular Needle Electrodes Inserted into the Lateral Cricoarytenoid Muscle Versus Intra-laryngeal Electrodes in Patients Undergoing Thyroid Surgery

Objective. To evaluate the effectiveness and safety of intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) using paired intramuscular needle electrodes inserted into the lateral cricoarytenoid muscle during thyroid surgery, and to compare this method with the traditional technique employing an endotracheal tube with integrated electromyographic (EMG) electrodes.
Material and methods. A multicenter prospective study was conducted from 2021 to 2024 involving 129 patients undergoing surgery for thyroid diseases. Participants were divided into three groups: • IONM with paired intramuscular needle electrodes placed in the lateral cricoarytenoid muscle (n=49); • IONM using EMG endotracheal tube (n=31); • control group with visual RLN identification only (n=49). All patients underwent pre- and postoperative vocal fold mobility assessments, with follow-up laryngoscopy when indicated.

Results. The incidence of postoperative laryngeal muscle paresis/paralysis was significantly lower in both IONM groups compared to the control (p=0.039 and p=0.021 for groups 1 and 2, respectively). There were no statistically significant differences in electrophysiological parameters (latency and amplitude) between the intramuscular and EMG-tube methods (p>0.05). The novel intramuscular method showed consistent signal acquisition, minimized the risk of false signal loss, and was technically simpler and potentially more cost-effective.
Conclusion. The application of paired intramuscular needle electrodes into the lateral cricoarytenoid muscle provides a reliable and safe alternative to conventional EMG-tube-based IONM. It circumvents major limitations such as electrode misplacement and signal dropout associated with endotracheal methods. This technique may be particularly advantageous in cases where EMG tube use is technically challenging or impossible, such as in patients with tracheostomy. The findings strongly support the routine implementation of IONM to reduce the risk of RLN injury in thyroid surgery, and this new technique expands the armamentarium of effective monitoring strategies.
Keywords: intraoperative neurophysiological monitoring, recurrent laryngeal nerve, laryngeal muscles, needle electrodes, electromyography, endotracheal intubation, thyroidectomy, vocal cord paralysis, postoperative complications, thyroid gland, thyroid surgery
Conflicts of interest. The authors have no conflicts of interest to declare.
Financing. The paper was done without sponsorship.