Evaluation of methods for identifying and monitoring laryngeal nerves

The functional goals of thyroid surgery are to ensure the integrity of the recurrent laryngeal nerve and the external branch of the superior laryngeal nerve, and to preserve normal voice. Objective —  to evaluate methods for identifying and monitoring laryngeal nerves and determine their significance in increasing its positive predictive value during thyroid surgery. Materials and methods. The results of neuromonitoring of the external branch of the superior laryngeal nerve and the recurrent laryngeal nerve during thyroidectomy in 348 patients were analyzed. In 128 of them, the method of registration with sound signals using a laryngeal mask was used, in 186 — the method of visual and palpatory control of cricothyroid muscle contraction and laryngeal muscle contraction, and in 34 — the electromyography method using needle electrodes inserted into the thyroid cartilage Results. The studies conducted have shown that these methods are sensitive and easily reproducible. Their results are not affected by extraneous factors associated with the performance of the operation. One disadvantage is that the method using a laryngeal mask with sound signals cannot be used in continuous neuromonitoring mode. The visual and palpatory assessment method is subjective rather than objective. Its results cannot be quantified. It is not suitable for use in continuous monitoring mode. The needle electrode technique is highly sensitive, accurate, and objective. It can be used in intermittent and continuous modes. It is a viable alternative to the method of identifying laryngeal nerves using electrodes on the endotracheal tube. Conclusions. The analyzed methods of intraoperative identification and monitoring of laryngeal nerves are simple and easy to use, have high efficiency and accuracy. Their application allows for the replacement of neuromonitoring with electrodes on the endotracheal tube, simplify its implementation, increase specificity and positive predictive value up to 100%.