Continuous monitoring of the recurrent laryngeal nerve in thyroid surgery: a critical appraisal

Abstract

RLN traction injury is still the most common cause of RLN injury and is difficult to avoid with the application of I-IONM in thyroid surgery. C-IONM is useful to prevent the imminent traction injury by detecting progressive decreases in electromyographic amplitude combined with progressive latency increases. C-IONM seems to be a technological improvement. Likely, C-IONM by vagal nerve stimulation should enhance the standardization process, RLN intraoperative information, documentation, protection, training, and research in modern thyroid surgery. Although C-IONM is a promising technology at the cutting edge of research in thyroid surgery, we need more studies to assess in an evidence-based way all its advantages.

Electrophysiologic monitoring correlates of recurrent laryngeal nerve heat thermal injury in a porcine model

“…In recent years, a CIONM has been developed that employs repetitive vagal stimulation and provides continuous visual and acoustic feedback of nerve function to allow early phases of nerve injury to be immediately detected after possible injurious maneuver . In our previous animal study, we demonstrated that RLN traction injury showed graded partial EMG changes, and early release of the traction before EMG has degraded to LOS offers a good chance of EMG recovery.…”

Continuous intraoperative neural monitoring of the recurrent nerves in thyroid surgery: a quantum leap in technology

“…The skilful use of CIONM requires experience and observation of the EMG screen to quickly respond to abnormal EMG signal and alarms (37). Meaningful warning thresholds need to be defined and implemented such that automated alarms are sounded and visually displayed once a critical EMG threshold is exceeded.…”

Prediction of Postoperative Vocal Fold Function After Intraoperative Recovery of Loss of Signal

“…CIONM is thought to reduce permanent vocal fold palsy rates more effectively than IIONM (0% vs. 0.4%; P = .019) because it measures nerve electrophysiology more accurately, and continually verifies functional integrity of the vagus–RLN axis in real‐time. Altogether, CIOMN facilitates reversal of the injurious surgical maneuver associated with the electromyogram (EMG) alteration by alerting the surgeon to impending nerve injury …”