Intraoperative Neuromonitoring, Nerves at Risk and Staged Thyroidectomy, our Experience on 377 Consecutive Cases Nerves at risk and staged thyroidectomy in 377 cases

Main Article Content

Matteo Rossini
Federico Cozzani
Tommaso Loderer
Elena Bonati
Mario Giuffrida
Paolo Del Rio


IONM; intraoperative neuromonitoring; thyroidectomy; staged thyroidectomy; vocal cord palsy; RLN


Purpose: The aim of this study was firstly to report the experience of intermittent intraoperative neuromonitoring (I-IONM) and evaluate the impact of loss of signal (LOS) in staged thyroidectomy management.

Methods: We retrospectively reviewed patients who underwent total thyroidectomy, performed by a single surgeon in two years. All patients have been subjected to I-IONM. In case of intraoperative loss of signal (LOS), planned total thyroidectomy was always aborted. Six-month follow-up was performed. Postoperative dysphonia was evaluated with VHI-10 score in 3 time settings T1, during hospital stay, T2 after 30 days, T3 after 6 months. Dysphonia has been compared to IONM results to evaluate sensitivity and specificity.

Results: 377 patients were included. Incidence of dysphonia was calculated based on the number of nerves at risk (NAR). We evaluated a total of 724 NAR. LOS encountered were 43 cases (5.9% of total NAR), of these 14 were LOS 1 while 29 were LOS 2. 27 patients (3.7% of NAR) presented early post-operative dysphonia with VHI-10 score > 13 (T1), among these 16 had presented LOS at IONM (true positives) while11 had no LOS (false negatives). In T2 and T3 we reported a decrease in true positive cases increasing false positives. Sensitivity at T3 reached 85.7% while specificity and odds ratio were respectively 94.8% and 110.

Conclusions: Given the high sensitivity and specificity, IONM should be considered a useful tool for thyroid surgery and its use should be suggested for patients undergoing planned total thyroidectomy. Its right application may cancel the risk of bilateral paralysis.


Download data is not yet available.
Abstract 36 | PDF Downloads 17


Dionigi G, Boni L, Rovera F, et al. (2010) Postoperative laryngoscopy in thyroid surgery: proper timing to detect recurrent laryngeal nerve injury. Langenbecks Arch Surg 395:327-31. 10.1007/s00423-009-0581-x
2. Varaldo E, Ansaldo GL, Mascherini M et al. (2014) Neurological complications in thyroid surgery: a surgical point of view on laryngeal nerves. Front Endocrinol (Lausanne). 15(5):108
3. Minuto, M.N., Reina, S., Monti, E. et al. (2019). Morbidity following thyroid surgery: acceptable rates and how to manage complicated patients. J Endocrinol Invest 42, 1291–1297
4. Rosato L, Avenia N, Bernante P et al. (2004) Complications of thyroid surgery: analysis of a multicentric study on 14,934 patients operated on in Italy over 5 years. World J Surg 28(3):271–276
5. Efremidou EI, Papageorgiou MS, Liratzopoulos N, Manolas KJ. (2009) The efficacy and safety of total thyroidectomy in the management of benign thyroid disease: a review of 932 cases. Can J Surg 52(1):39–44
6. Echternach M, Maurer CA, Mencke T et al. (2009) Laryngeal complications after thyroidectomy: is it always the surgeon? Arch Surg 144(2):149–153
7. Duclos A, Peix JL, Colin C, Kraimps JL, Menegaux F, Pattou F, et al. (2012) Influence of experience on performance of individual surgeons in thyroid surgery a prospective cross sectional multicenter study. BMJ 344. 23
8. Rosato L, De Crea C, Bellantone R et al. (2016) Diagnostic, therapeutic and health-care management protocol in thyroid surgery: a position statement of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB). J Endocrinol Invest 39(8):939–953
9. Morton RP, Whitfield P, Al-Ali S. (2006) Anatomical and surgical considerations of the external branch of the superior laryngeal nerve: a systematic review. Clin Otolaryngol 31(5): 368–374.
10. Cheruiyot I, Kipkorir V, Henry BM et al. (2018) Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis. Langenbecks Arch Surg 403:811–823
11. Kandil E, Mohamed SE, Deniwar A et al. (2015) Electrophysiologic identification and monitoring of the external branch of superior laryngeal nerve during thyroidectomy. Laryngoscope 125:1996–2000
12. Barczyński M, Randolph GW, Cernea CR et al. (2013) External branch of the superior laryngeal nerve monitoring during thyroid and parathyroid surgery: international neural monitoring study group standards guideline statement. Laryngoscope 123:S1–S4
13. Sosa JA, Bowman HM, Tielsch JM et al. (1998) The importance of surgeon experience for clinical and economic outcomes from thyroidectomy. Ann Surg 228:320–330
14. Shedd DP, Burget GC. (1966) Identification of the recurrent laryngeal nerve. Arch Surg 92:861–4.
15. Schneider R, Randolph GW, Dionigi G, et Al. (2018) International neural monitoring study group guideline 2018 part I: Staging bilateral thyroid surgery with monitoring loss of signal. Laryngoscope 128 Suppl 3:S1-S17.
16. Chandrasekhar SS., Randolph GW., Seidman MD. et al. (2013) American Academy of Otolaryngology Head and Neck Surgery. Clinical Practice Guidelines: improving voice outcomes after thyroid surgery. Otolaryngol. Head Neck Surg. 148, S1–S37
17. Chan WF, Lang BH, Lo CY. (2006) The role of intraoperative neu-romonitoring of recurrent laryngeal nerve during thyroidectomy: a comparative study on 1000 nerves at risk. Surgery 140, 866–872
18. Higgins TS, Gupta R, Ketcham AL, et al. (2011) Recurrent laryngeal nerve monitoring versus identification alone on post-thyroidectomy true vocal fold palsy: a meta-analysis. Laryngoscope 121, 1009–1017
19. Barczynski M, Konturek A, Chichon S. (2009) Randomized clinical trial of visulalization versus neuromonitoring of recurrent laryngeal nerves during thyroidectomy. Br. J. Surg. 96, 240–246
20. Haugen BR, Alexander EK, Bible KC, Doherty G, Mandel SJ, Nikiforov YE, Pacini F, Randolph G, Sawka A, Schlumberger M, Schuff KG, Sherman SI, Sosa JA, Steward D, Tuttle RM, Wartofsky L. (2015) American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2015 Oct 14
21. Kim, Hoon & Liu, Xiaoli & Chai, Young Jun & Tufano, Ralph & Dralle, Henning & Dionigi, Gianlorenzo. (2018). Standards for Intraoperative Neuromonitoring in Thyroid Operations. Journal of Endocrine Surgery. 18. 37. 10.16956/jes.2018.18.1.37.
22. Sun H, Tian W, Jiang K, et al. (2015) Clinical guidelines on intraoperative neuromonitoring during thyroid and parathyroid surgery. Ann Transl Med. 3(15):213. doi:10.3978/j.issn.2305-5839.2015.08.21
23. Forti S, Amico M, Zambarbieri A, Ciabatta A, Assi C, Pignataro L, Cantarella G. (2014) Validation of the Italian Voice Handicap Index-10. J Voice. 28(2):263.e17-263.e22. doi: 10.1016/j.jvoice.2013.07.013. Epub 2013 Oct 2. PMID: 24094800.
24. Arffa, Rachel E. et al. (2012) Normative Values for the Voice Handicap Index-10. Journal of Voice. 26,4, 462 – 465.
25. Dralle H, Sekulla C, Haerting J, Timmermann W, Neumann HJ, Kruse E, Grond S, Mühlig HP, Richter C, Voß J, Thomusch O, Lippert H, Gastinger I, Brauckhoff M, Gimm O. (2004) Risk factors of paralysis and functional outcome after recurrent laryngeal nerve monitoring in thyroid surgery. Surgery. 36, 6,1310-1322,
26. Schneider R, Randolph GW, Dionigi G, Wu CW, Barczynski M, Chiang FY, Al-Quaryshi Z, Angelos P, Brauckhoff K, Cernea CR, Chaplin J, Cheetham J, Davies L, Goretzki PE, Hartl D, Kamani D, Kandil E, Kyriazidis N, Liddy W, Orloff L, Scharpf J, Serpell J, Shin JJ, Sinclair CF, Singer MC, Snyder SK, Tolley NS, Van Slycke S, Volpi E, Witterick I, Wong RJ, Woodson G, Zafereo M, Dralle H. (2018) International neural monitoring study group guideline 2018 part I: Staging bilateral thyroid surgery with monitoring loss of signal. Laryngoscope 128 Suppl 3:S1-S17.
27. Edmund S. Cibas and Syed Z. Ali. (2017) The 2017 Bethesda System for Reporting Thyroid Cytopathology. Thyroid. 1341-1346.
28. Cirocchi R, Arezzo A, D’Andrea V et al. (2019) Intraoperative neuromonitoring versus visual nerve identifcation for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery. Cochrane Database Syst Rev 19(1):CD012483
29. Chiang FY, Lu IC, Kuo WR et al. (2008) The mechanism of recurrent laryngeal nerve injury during thyroid surgery—the application of intraoperative neuromonitoring. Surgery 143, 743–749
30. Marin Arteaga A, Peloni G, Leuchter I, et al. (2018) Modification of the Surgical Strategy for the Dissection of the Recurrent Laryngeal Nerve Using Continuous Intraoperative Nerve Monitoring. World J Surg. Feb;42(2):444-450.
31. Francis DO, Pearce EC, Ni S, et al. (2014) Epidemiology of vocal fold paralyses after total thyroidectomy for well‐differentiated thyroid cancer in a Medicare population. Otolaryngol Head Neck Surg. 150:548‐557.
32. Alesina PF, Hinrichs J, Meier B, et al. (2014) Intraoperative neuromonitoring for surgical training in thyroid surgery: its routine use allows a safe operation instead of lack of experienced mentoring. World J Surg. Mar;38(3):592-8.
33. Dralle H, Sekulla C, Lorenz K, Nguyen Thanh P, Machens A. (2012) Loss of the nerve monitoring signal during bilateral thyroid surgery. Br. J. Surg 99:1089-1095
34. Chiang FY, Lu IC, Tsai CJ, Hsiao PJ, Hsu CC, Wu CW. (2011)Does extensive dissection of recurrent laryngeal nerve during thyroid operation increase the risk of nerve injury? Evidence from the application of intraoperative neuromonitoring. Am J Otolaryngol. 32(6):499-503
35. Sun H, Tian W, Jiang K, et al. (2015) Clinical guidelines on intraoperative neuromonitoring during thyroid and parathyroid surgery. Ann Transl Med. 3(15):213. doi:10.3978/j.issn.2305-5839.2015.08.21
36. Chiang FY, Lee KW, Chen HC, et al. (2010) Standardization of intraoperative neuromonitoring of recurrent laryngeal nerve in thyroid operation. World J Surg 34:223–229. 122
37. Haugen BR, Alexander EK, Bible KC, et al. (2016) American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid 26:1–133.
38. Del Rio P, Cozzani F, Puteo N, Loderer T, Rossini M, Bonati E. (2019) IONM and thyroidectomy in benign thyroid disease. Analysis of adverse events. G Chir. 40(3):174-181.
39. Pröschel U, Eysholdt U. (1993) Short-term changes in the larynx and voice after intubation. Laryngorhinootologie 72(2):93–97
40. Cavicchi O, Burgio L, Cioccoloni E, Piccin O, Macri G, Schiavon P, Dionigi G. (2018) Intraoperative intermittent neuromonitoring of inferior laryngeal nerve and staged thyroidectomy: our experience. Endocrine 62:560-565
41. Melin M, Schwarz K, Lammers BJ, Goretzki PE. (2013) IONM-guided goiter surgery leading to two-stage thyroidectomy indication and results. Langenbecks Arch Surg 398:411–418.
42. Caragacianu D, Kamani D, Randolph GW. (2013) Intraoperative monitoring: normative range associated with normal postoperative glottic function. Laryngoscope 123:3026–3031.120.
43. Pavier Y, Saroul N, Pereira B, Tauveron I, Gilain L, Mom T. (2015) Acute prediction of laryngeal outcome during thyroid surgery by electromyographiclaryngeal monitoring. Head Neck 37:835–839.
44. Dralle H, Sekulla C, Lorenz K et al. German IONM Study Group. (2004) Intraoperative monitoring of the recurrent laringeal nerve in thyroid surgery. World J. Surg. 32, 1098–1102

Most read articles by the same author(s)

1 2 > >>