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What are normal quantitative parameters of intraoperative neuromonitoring (IONM) in thyroid surgery?

  • Endocrine Surgery
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Abstract

Purpose

This study aimed at definition of normal quantitative parameters in intraoperative neuromonitoring during thyroid surgery. Only few and single center studies described quantitative data of intraoperative neuromonitoring. Definition of normal parameters in intraoperative neuromonitoring is believed to be a prerequisite for interpretation of results and intraoperative findings when using this method. Moreover, these parameters seem important in regard to the prognostic impact of the method on postoperative vocal cord function.

Material and methods

In a prospective multicenter study, quantitative analysis of vagal nerve stimulation pre- and postresection was performed in thyroid lobectomies. A standardized protocol determined set up and installation of neuromonitoring and defined assessment of quantitative parameters. Data of intraoperative neuromonitoring were respectively print-documented and centrally analyzed.

Results

In six participating centers a total of 1,289 patients with 1,996 nerves at risk underwent surgery for benign and malignant thyroid disease. Median amplitude was significantly larger for the right vs. left vagal nerve, latency was significantly longer for left vs. right vagal nerve and duration of the left vs. right vagal nerve significantly longer. Age disparities were only present in form of significantly higher amplitude in patients below 40 years; however, there is no continuous increase with age. Regarding gender, there was significantly higher amplitude and smaller latency in women compared to men. Duration of surgery revealed a reduction of amplitude with operative time; contrarily, latency and signal duration remained stable. The type of underlying thyroid disease showed no influence on quantitative parameters of intraoperative neuromonitoring.

Conclusions

Systematic data of multicenter evaluation on quantitative intraoperative neuromonitoring parameters revealed differences between left and right vagal nerves in regard to amplitude, latency and duration of signal, gender, and age. The nature of thyroid disease showed no significant influence on quantitative parameters of intraoperative neuromonitoring. This study presents for the first time collective data of a large series of nerves at risk in a multicenter setting. It seems that definitions of “normal” parameters are prerequisite for the interpretation of quantitative changes of intraoperative neuromonitoring during thyroid surgery to enable interpretation of influence on surgical strategy and prediction of postoperative vocal cord function.

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References

  1. Möller A (1955) Practical aspects of intraoperative cranial nerve monitoring. Adv Otolaryngol Head Neck Surg 9:147–181

    Google Scholar 

  2. Satoh I (1978) Evoked electromyographic test applied for recurrent laryngeal paralysis. Laryngoscope 88:2022–2031

    Article  CAS  PubMed  Google Scholar 

  3. Rice DH, Cone-Wesson B (1991) Intraoperative recurrent laryngeal nerve monitoring. Otolaryngol Head Neck Surg 105:372–375

    CAS  PubMed  Google Scholar 

  4. Sanders I, Aviv J, Biller H (1986) Transcutaneous electrical stimulation of the recurrent laryngeal nerve: a method for controlling vocal cord position. Otolaryngol Head Neck Surg 95:152–157

    CAS  PubMed  Google Scholar 

  5. Synder S, Hendricks J (2005) Intraoperative neurophysiology testing of the recurrent laryngeal nerve: plaudits and pitfalls. Surgery 138:1183–1192

    Article  Google Scholar 

  6. Dralle H, Sekulla C, Lorenz K et al (2008) Intraoperative monitoring of the recurrent laryngeal nerve in thyroid surgery. World J Surg 32:1358–1366

    Article  CAS  PubMed  Google Scholar 

  7. Dralle H, Kruse E, Hamelmann W et al (2004) Nicht jeder Stimmlippenstillstand nach Schilddrüsenoperation ist eine chirurgisch bedingte Recurrensparese. Chirurg 75:810–822

    CAS  PubMed  Google Scholar 

  8. Koester ZP, Wolf S (2003) Neuromonitoring in thyroid surgery: the view of the laryngologist. Eur Surg 35:246–249

    Article  Google Scholar 

  9. Medtronic company (2001) NIM 2.0 manufacturers manual; Tolochenaz, Switzerland

  10. Randolph GW (2003) Intraoperative recurrent laryngeal electromyographic nerve monitoring during thyroid surgery. The prediction of postoperative vocal cord function. In: Surgery of the thyroid and parathyroid glands. Saunders, Philadelphia, pp. 316–342

  11. Mermelstein M, Von Weiler R, Rubinstein E (1996) Intraoperative identification of laryngeal nerves with laryngeal electromyography. Laryngoscope 106:752–756

    Article  CAS  PubMed  Google Scholar 

  12. Prass R, Luders H (1986) Acoustic (loudspeaker) facial electromyographic monitoring. Part I: evoked electroneurographic activity during acoustic neuroma resection. Neurosurgery 19:392–400

    Article  CAS  PubMed  Google Scholar 

  13. Rodriguez A, Myers B, Ford C (1990) Laryngeal electromyography in the diagnosis of laryngeal nerve injury. Arch Phys Med Rehabil 71:587–590

    Google Scholar 

  14. Schneider R, Przybyl J, Pliquett U et al (2010) A new vagal anchor electrode for real-time monitoring of the recurrent laryngeal nerve. Am J Surg 199:507–514

    Article  PubMed  Google Scholar 

  15. Scott A, Chong P, Hartnick C et al (2010) Spontaneous and evoked laryngeal electromyography of the thyroarytenoid muscles: a canine model for intraoperative recurrent laryngeal nerve monitoring. Ann Otol Rhinol Laryngol 119:54–63

    PubMed  Google Scholar 

  16. Hermann M, Hellebart C, Freissmuth M (2004) Neuromonitoring in thyroid surgery. Prospective evaluation of intraoperative electrophysiological responses for the prediction of recurrent laryngeal nerve injury. Ann Surg 240:9–17

    Article  PubMed  Google Scholar 

  17. Wu C, Lu I, Randolph W et al (2009) Investigation of optimal intensity and safety of electrical nerve stimulation during intraoperative neuromonitoring of the recurrent laryngeal nerve: a prospective porcine model. Head Neck 10:1–7

    Google Scholar 

Download references

Acknowledgments

The authors are greatly indebted to the participating members of the German Neuromonitoring Study Group: Ch. Blankenburg, MD, Dresden; W. Hamelmann, MD, Kassel; H. Heidemann, Berlin; B. Koch, MD, Kaiserslautern; D. Lehmann, MD, Nordhausen; N. Müller, MD, Kaiserslautern; A. Szelenyi, MD, Frankfurt/Main; W. Timmermann, MD, Hagen.

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Correspondence to Kerstin Lorenz.

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Lorenz, K., Sekulla, C., Schelle, J. et al. What are normal quantitative parameters of intraoperative neuromonitoring (IONM) in thyroid surgery?. Langenbecks Arch Surg 395, 901–909 (2010). https://doi.org/10.1007/s00423-010-0691-5

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  • DOI: https://doi.org/10.1007/s00423-010-0691-5

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