Pre-Prototype Stimulating and Recording Endotracheal Tube for Continuous Monitoring of the Recurrent Laryngeal Nerve During Thyroid Surgery

Introduction: Continuous intraoperative neural monitoring (C-IONM) is a promising technology used to decrease recurrent laryngeal nerve (RLN) damage during thyroid surgery. However, C- IONM use is limited due to its challenging application. C-IONM requires dissection of the carotid sheath and placement of an electrode around the vagus nerve (VN). In our study, we simultan- eously stimulated and monitored the proximal RLN trans-tracheally using surface electrodes that were positioned solely on the endotracheal tube. Methods: We described the design, implementation, and testing of a pre-prototype, combined stimulating and recording endotracheal tube (SRET) that continually delivered current from tube edge, and tested the function of the RLN at the vocal cords (VC). The SRET was tested in vivo on 10 RLNs using 5 pigs as animal models. Results: The SRET was capable of the following, delivery of continuous trans-tracheal stimulation to the proximal RLN, continuous trans-tracheal stimulation-induced VC movement, and standard ipsilateral RLN biphasic waveforms with latency and amplitude; and recording evoked responses were recorded in the ipsilateral RLN. Conclusion: The pre-prototype SRET represents a possible advancement in technology because it simplified the C-IONM. Thus, the SRET provides a minimally invasive, alternative application to the C-IONM vagal nerve cuff electrodes.