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Neuromonitoring and video-assisted thyroidectomy: a prospective, randomized case-control evaluation



This study evaluates the role of intraoperative neuromonitoring (IONM) in video-assisted thyroidectomy (VAT) with emphasis given to the identification of recurrent laryngeal nerve (RLN) and external branch of superior laryngeal nerve (EBSLN).


The study was based on a prospectively randomized series comprising 72 standard VAT gasless approaches. In the control group (N = 36), the laryngeal nerves were identified by 30° 5-mm endoscope magnification solely. The standard technique of the IONM group (N = 36) consisted of localizing and monitoring EBSLN, both vagus and RLNs, before and after thyroid resection to prove nerve integrity. Surgical outcomes were mean operative time, nerve representation, incision length, and morbidity.


All procedures were performed successfully. There were no instances of equipment malfunction or interference. No permanent complications occurred in either group. The incidences of temporary RLN injury were 2.7% (1 patient) and 8.3% (3 patients) in the IONM and control group, respectively. The EBSLN was identified better in the IONM group: 83.6% versus 42% (p < 0.05). In the IONM group, a negative electromyography (EMG) response indicated an altered function of RLN and stage thyroidectomy was scheduled.


This is the first VAT series with a standardized IONM technique. The technical feasibility and safety of IONM in selected patients seem acceptable. Neuromonitoring during VAT is effective in providing identification and function of laryngeal nerves. IONM enables surgeons to feel more comfortable with their approach to VAT. A reduction of rates for postoperative complications could not be demonstrated in the present study. Larger series are needed for further evaluation.

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  1. 1.

    Yalcxin B (2006) Anatomic configurations of the recurrent laryngeal nerve and inferior thyroid artery. Surgery 139(2):181–187

  2. 2.

    Brok HA, Copper MP, Stroeve RJ, Ongerboer de Visser BW, Venker-van Haagen AJ, Schouwenburg PF (1999) Evidence for recurrent laryngeal nerve contribution in motor innervation of the human cricopharyngeal muscle. Laryngoscope 109(5):705–708

  3. 3.

    Cernea CR, Ferraz AR, Nishio S, Dutra A Jr, Hojaij FC, dos Santos LR (1992) Surgical anatomy of the external branch of the superior laryngeal nerve. Head Neck 14(5):380–383

  4. 4.

    Kark AE, Kissin MW, Auerbach R, Meikle M (1984) Voice changes after thyroidectomy: role of the external laryngeal nerve. Br Med J (Clin Res Ed) 289(6456):1412–1415

  5. 5.

    Jatzko GR, Lisborg PH, Müller MG, Wette VM (1994) Recurrent nerve palsy after thyroid operations–principal nerve identification and a literature review. Surgery 115(2):139–144

  6. 6.

    Loré JM Jr, Kokocharov SI, Kaufman S, Richmond A, Sundquist N (1998) Thirty-eight-year evaluation of a surgical technique to protect the external branch of the superior laryngeal nerve during thyroidectomy. Ann Otol Rhinol Laryngol 107(12):1015–1022

  7. 7.

    Jansson S, Tisell LE, Hagne I, Sanner E, Stenborg R, Svensson P (1988) Partial superior laryngeal nerve (SLN) lesions before and after thyroid surgery. World J Surg 12(4):522–527

  8. 8.

    Timmermann W, Hamelmann WH, Thomusch O, Sekulla C, Grond S, Neumann HJ, Kruse E, Mühlig HP, Richter C, Voss J, Dralle H (2004) Effectiveness and results of intraoperative neuromonitoring in thyroid surgery. Statement of the Interdisciplinary Study Group on Intraoperative Neuromonitoring of Thyroid Surgery. Chirurg 75(9):916–922

  9. 9.

    Thomusch O, Machens A, Sekulla C, Ukkat J, Lippert H, Gastinger I, Dralle H (2000) Multivariate analysis of risk factors for postoperative complications in benign goiter surgery: prospective multicenter study in Germany. World J Surg 24(11):1335–1341

  10. 10.

    Thomusch O, Sekulla C, Machens A, Neumann HJ, Timmermann W, Dralle H (2004) Validity of intra-operative neuromonitoring signals in thyroid surgery. Langenbecks Arch Surg 389(6):499–503

  11. 11.

    Miccoli P, Bellantone R, Mourad M, Walz M, Raffaelli M, Berti P (2002) Minimally invasive video-assisted thyroidectomy: multiinstitutional experience. World J Surg 26(8):972–975

  12. 12.

    Pacini F, Schlumberger M, Dralle H, Elisei R, Smit JW, Wiersinga W, the European Thyroid Cancer Taskforce (2006) European consensus for the management of patients with differentiated thyroid carcinoma of the follicular epithelium. Eur J Endocrinol 154:787–803

  13. 13.

    Cohen SM, Jacobson BH, Garrett CG, Noordzij JP, Stewart MG, Attia A, Ossoff RH, Cleveland TF (2007) Creation and validation of the Singing Voice Handicap Index. Ann Otol Rhinol Laryngol 116(6):402–406

  14. 14.

    Dralle H, Sekulla C, Lorenz K, Brauckhoff M, Machens A, the German IONM Study Group (2008) Intraoperative monitoring of the recurrent laryngeal nerve in thyroid surgery. World J Surg [ahead of print]

  15. 15.

    Moosman DA, DeWeese MS (1968) The external laryngeal nerve as related to thyroidectomy. Surg Gynecol Obstet 127(5):1011–1016

  16. 16.

    Dionigi G, Rovera F, Boni L, Castano P, Dionigi R (2006) Surgical site infections after thyroidectomy. Surg Infect (Larchmt) 7:S117–S120

  17. 17.

    Miccoli P, Minuto MN, Ugolini C, Pisano R, Fosso A, Berti P (2008) Minimally invasive video-assisted thyroidectomy for benign thyroid disease: an evidence-based review. World J Surg [ahead of print]

  18. 18.

    Alvarado R, McMullen T, Sidhu SB, Delbridge LW, Sywak MS (2008) Minimally invasive thyroid surgery for single nodules: an evidence-based review of the lateral mini-incision technique. World J Surg [ahead of print]

  19. 19.

    Ujiki MB, Sturgeon C, Denham D, Yip L, Angelos P (2006) Minimally invasive video-assisted thyroidectomy for follicular neoplasm: is there an advantage over conventional thyroidectomy? Ann Surg Oncol 13(2):182–186

  20. 20.

    Miccoli P, Berti P, Raffaelli M, Materazzi G, Baldacci S, Rossi G (2001) Comparison between minimally invasive video-assisted thyroidectomy and conventional thyroidectomy: a prospective randomized study. Surgery 130(6):1039–1043

  21. 21.

    Chatenever D (2006) Minimally invasive surgical visualization: experience in transition. Surg Endosc 20(S2):S412–S418

  22. 22.

    Hagiike M, Phillips EH, Berci G (2007) Performance differences in laparoscopic surgical skills between true high-definition and three-chip CCD video systems. Surg Endosc 21(10):1849–1854

  23. 23.

    Berti P, Materazzi G, Conte M, Galleri D, Miccoli P (2002) Visualization of the external branch of the superior laryngeal nerve during video-assisted thyroidectomy. J Am Coll Surg 195(4):573–574

  24. 24.

    Terris DJ, Anderson SK, Watts TL, Chin E (2007) Laryngeal nerve monitoring and minimally invasive thyroid surgery: complementary technologies. Arch Otolaryngol Head Neck Surg 133(12):1254–1257

  25. 25.

    Bärlehner E, Benhidjeb T (2008) Cervical scarless endoscopic thyroidectomy: axillo-bilateral-breast approach (ABBA). Surg Endosc 22(1):154–157

  26. 26.

    Sasaki A, Nakajima J, Ikeda K, Otsuka K, Koeda K, Wakabayashi G (2008) Endoscopic thyroidectomy by the breast approach: a single institution’s 9-year experience. World J Surg 32(3):381–385

  27. 27.

    Duh QY (2003) Minimally invasive endocrine surgery: standard of treatment or hype? Surgery 134(6):849–857

  28. 28.

    Miccoli P, Materazzi G, Berti P (2008) Minimally invasive video-assisted lateral lymphadenectomy: a proposal. Surg Endosc 22(4):1131–1134

  29. 29.

    Miccoli P, Elisei R, Donatini G, Materazzi G, Berti P (2007) Video-assisted central compartment lymphadenectomy in a patient with a positive RET oncogene: initial experience. Surg Endosc 21(1):120–123

  30. 30.

    Berti P (2004) Materazzi G, Galleri D, Donatini G, Minuto M, Miccoli P (2004) Video-assisted thyroidectomy for Graves’ disease: report of a preliminary experience. Surg Endosc 18(8):1208–1210

  31. 31.

    Caldarelli DD, Holinger LD (1980) Complications and sequelae of thyroid surgery. Otolaryngol Clin North Am 13(1):85–97

  32. 32.

    Patlow C, Norton J, Brennan M (1986) Vocal cord paralysis and reoperative parathyroidectomy. Ann Surg 203:282–285

  33. 33.

    Beldi G, Kinsbergen T, Schlumpf R (2004) Evaluation of intraoperative recurrent nerve monitoring in thyroid surgery. World J Surg 28(6):589–591

  34. 34.

    Loch-Wilkinson TJ, Stalberg PL, Sidhu SB, Sywak MS, Wilkinson JF, Delbridge LW (2007) Nerve stimulation in thyroid surgery: is it really useful? ANZ J Surg 77(5):377–380

  35. 35.

    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(1):9–17

  36. 36.

    Eisele DW (1996) Intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve. Laryngoscope 106(4):443–449

  37. 37.

    Aina EN, Hisham AN (2001) External laryngeal nerve in thyroid surgery—recognition and surgical implications. ANZ J Surg 71:212–214

  38. 38.

    Kern KA (1993) Medicolegal analysis of errors in diagnosis and treatment of surgical endocrine disease. Surgery 114(6):1167–1173

  39. 39.

    Dralle H (2006) Impact of modern technologies on quality of thyroid surgery. Langenbecks Arch Surg 391(1):1–3

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Written consent from the patients was obtained for publication of this report. Supported in part by grants from the Italian Ministry of Education, University and Research (FAR, Project 2007 “Il sistema di monitoraggio del nervo laringeo ricorrente e della branca sterna del nervo laringeo superior durante interventi di tiroidectomia mininvasiva”). The authors are grateful to Professors H. Dralle, G.W. Randolph, and L. Bartalena for general support, excellent technical assistance, and helpful discussion.

Authors’ contributions

GD: acquisition of data; FR, LB: study conception and design; GD: analysis and interpretation of data; LB, BA: drafting of manuscript; RD: Critical revision and supervision.

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Correspondence to Gianlorenzo Dionigi.

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Dionigi, G., Boni, L., Rovera, F. et al. Neuromonitoring and video-assisted thyroidectomy: a prospective, randomized case-control evaluation. Surg Endosc 23, 996–1003 (2009).

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  • Video-assisted thyroidectomy
  • Morbidity
  • Neuromonitoring
  • Recurrent laryngeal nerve
  • External branch of the superior laryngeal nerve
  • Stage thyroidectomy