Langenbeck's Archives of Surgery

, Volume 404, Issue 6, pp 703–709 | Cite as

New placement of recording electrodes on the thyroid cartilage in intra-operative neuromonitoring during thyroid surgery

  • Sam Van SlyckeEmail author
  • K. Van Den Heede
  • K. Magamadov
  • N. Brusselaers
  • H. Vermeersch
Original Article



During thyroid surgery, extreme caution is needed not to harm the recurrent laryngeal nerve and to avoid vocal cord palsy. Intra-operative neuromonitoring became increasingly popular as an adjunct to the gold standard of visual identification of the recurrent laryngeal nerve (RLN). Electromyographic (EMG) responses are normally recorded by electrodes attached to the endotracheal tube. Alteration in position can lead to false loss of signal. We developed thyroid cartilage electrodes that can be fixed directly onto the thyroid cartilage.

Study design

Prospective clinical cohort


Thyroid surgery with intra-operative neuromonitoring using both endotracheal tube-based electrodes and thyroid cartilage electrodes was performed in 25 patients undergoing thyroid surgery. EMG data were collected and reported as median and interquartile ranges (IQR), and the results were compared with the x Wilcoxon signed-rank test for paired measurements.


After stimulating vagal nerve (VN), recurrent laryngeal nerve (RLN) and external branch of the superior laryngeal nerve (EBSLN), significantly higher EMG amplitudes were measured before and after thyroid resection for the thyroid cartilage (TC) electrodes, in all comparisons except for the right VN. At the level of the left EBSLN, median amplitude of 560 mV (IQR 190–1050) before and 785 mV (IQR 405–3670) after resection was noted. At the level of the right EBSLN, median amplitude of 425 μV (IQR 257–698) before and 668 mV (IQR 310–1425) after resection was noted. Median amplitudes of 760 mV (IQR 440–1180) and 830 mV (IQR 480–1490) were noted at the left RLN, median amplitudes of 695 mV (IQR 405–1592) and 1078 mV (IQR 434–1895) were noted at the right RLN.


Thyroid cartilage electrodes appear to be a feasible and reliable alternative for endotracheal electrodes.


Intra-operative neuromonitoring Thyroid cartilage electrodes Thyroid surgery Recurrent laryngeal nerve External branch of the superior laryngeal nerve 


Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all participants in the study.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Sam Van Slycke
    • 1
    • 2
    • 3
    Email author
  • K. Van Den Heede
    • 1
  • K. Magamadov
    • 1
  • N. Brusselaers
    • 2
    • 4
    • 5
  • H. Vermeersch
    • 5
    • 6
  1. 1.Department of General and Endocrine SurgeryOnze-Lieve-Vrouw (OLV) Clinic AalstAalstBelgium
  2. 2.Department of Head, Neck and Maxillofacial SurgeryUniversity Hospital GhentGhentBelgium
  3. 3.Department of General SurgeryAZ DamiaanOstendBelgium
  4. 4.Centre for Translational Microbiome Research Department of Microbiology, Tumour and Cell biology, Karolinska InstitutetKarolinska HospitalStockholmSweden
  5. 5.Department of OtorhinolaryngologyUniversity Hospital GhentGhentBelgium
  6. 6.Department of Plastic and Reconstructive SurgeryUniversity Hospital GhentGhentBelgium

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