Affiliation:
1. Department of Breast and Endocrine Surgery Haukeland University Hospital Bergen Norway
2. Department of Clinical Sciences University of Bergen Bergen Norway
3. Department of Anesthesia and Intensive Care Haukeland University Hospital Bergen Norway
4. Department of Clinical Medicine University of Bergen Bergen Norway
5. Norwegian research institute (NORCE) Bergen Norway
Abstract
ObjectiveVocal cord (VC) movement has been demonstrated by the use of accelerometry (ACC) to decrease in parallel with the electromyographic amplitude (EMG) during ongoing traction injury to the recurrent laryngeal nerve (RLN). When RLN function recovers, discrepancies between EMG and VC movement have been reported in clinical and experimental studies. The present study was conducted to clarify the actual relationship between EMG and VC movement measured by ACC during nerve recovery.MethodsEMG obtained by continuous nerve monitoring (C‐IONM) was compared with ACC during traction injury to the RLN, and throughout 40‐min nerve recovery. A three‐axis linear accelerometer probe was attached to the VC, and ACC data were registered as described. Traction damage was applied to the RLN until there was a 70% amplitude decrease from baseline EMG, or until loss of signal (LOS), that is, EMG values ≤100 μV.ResultsThirty‐two RLN from 16 immature pigs were studied. Correlation between EMG and ACC were calculated during nerve injury and nerve recovery. The mean correlations were for the 70% and LOS group from start to end of traction: 0.82 (±0.17) and 0.87 (±0.17), respectively. Corresponding correlation coefficients during 40‐min recovery was 0.50 (±0.48) in the 70% group and 0.53 (±0.33) in the LOS group.ConclusionThere is a high correlation between EMG and VC movement during nerve injury, and a moderate correlation during early nerve recovery. EMG recovery after RLN injury ensures sufficient VC function as assessed by ACC.Level of EvidenceN/A Laryngoscope, 2023