Skip to main content
SpringerLink
Log in

Surgical Approach and Monitoring of the External Branch of the Superior Laryngeal Nerve (EBSLN)

  • Chapter
  • First Online:
The Recurrent and Superior Laryngeal Nerves

  • 1264 Accesses

Abstract

In this chapter, methods of intraoperative preservation and monitoring of the external branch of the superior laryngeal nerve (EBSLN) are described in detail. Contrary to routine dissection of the recurrent laryngeal nerve (RLN), most surgeons tend to avoid rather than routinely expose and identify the EBSLN during thyroidectomy. The EBSLN is believed to be the most commonly underestimated morbidity following thyroid surgery and is at a high risk of injury during dissection of the superior thyroid pole in the course of thyroidectomy in approximately one-third of patients (Cernea type 2A and 2B nerves). The laryngeal head of the sternothyroid muscle is a robust landmark for the course of the EBSLN as it descends along the inferior constrictor to the cricothyroid muscle (CTM). In up to 20 % of cases the nerve may not be able to be visualized due to a subfascial course along the inferior constrictor muscle, and hence use of intraoperative neural monitoring (IONM) can significantly improve the identification rate of the EBSLN during thyroidectomy. CTM twitch and glottic EMG recordings are both methods of IONM which are recommended in all cases of thyroid surgery, especially those which might jeopardize the EBSLN. A technique of togging the stimulator probe between the tissue of the superior thyroid pole vessels (with negative stimulation) and the region of the laryngeal head of the sternothyroid muscle (with positive stimulation) is recommended to assure preservation of the EBSLN. Transverse division of the superior edge of sternothyroid muscle and gentle traction of the superior thyroid pole into lateral and caudal direction followed by blunt dissection within the avascular plane of sternothyroid-laryngeal triangle allow for improving exposure of the EBSLN which is usually descending parallel to superior thyroid artery and is lying on the fascia or between the fibers of the inferior constrictor muscle before its termination within CTM. Nerve stimulation can objectively identify the EBSLN, leading to a visible CTM twitch in all cases. EMG activity can currently be quantified in nearly 80 % of cases using standard EMG tubes, but in all patients using novel EMG tubes with anterior surface electrodes. The role of measuring the waveform amplitude in prognostication of EBSLN function is yet to be determined.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Log in via an institution

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 84.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 109.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 159.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Similar content being viewed by others

References

  1. Bevan K, Griffiths MV, Morgan MH. Cricothyroid muscle paralysis: its recognition and diagnosis. J Laryngol Otol. 1989;103:191–5.

    Article  CAS  PubMed  Google Scholar 

  2. Jansson S, Tisell LE, Hagne I, Sanner E, Stenborg R, Svensson P. Partial laryngeal nerve lesions before and after thyroid surgery. World J Surg. 1988;12:522–7.

    Article  CAS  PubMed  Google Scholar 

  3. Teitelbaum BJ, Wenig BL. Superior laryngeal nerve injury from thyroid surgery. Head Neck. 1995;17:36–40.

    Article  CAS  PubMed  Google Scholar 

  4. Cernea CR, Ferraz AR, Furlani J, Monteiro S, Nishio S, Hojaij FC, Dutra Júnior A, Marques LA, Pontes PA, Bevilacqua RG. Identification of the external branch of the superior laryngeal nerve during thyroidectomy. Am J Surg. 1992;164:634–9.

    Article  CAS  PubMed  Google Scholar 

  5. Randolph GW, Dralle H, Abdullah H, Barczynski M, Bellantone R, Brauckhoff M, Carnaille B, Cherenko S, Chiang FY, Dionigi G, Finck C, Hartl D, Kamani D, Lorenz K, Miccolli P, Mihai R, Miyauchi A, Orloff L, Perrier N, Poveda MD, Romanchishen A, Serpell J, Sitges-Serra A, Sloan T, Van Slycke S, Snyder S, Takami H, Volpi E, Woodson G, International Intraoperative Monitoring Study Group. Electrophysiologic recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery: international standards guideline statement. Laryngoscope. 2011;121 Suppl 1:S1–16.

    Article  PubMed  Google Scholar 

  6. Barczyński M, Randolph GW, Cernea CR, Dralle H, Dionigi G, Alesina PF, Mihai R, Finck C, Lombardi D, Hartl DM, Miyauchi A, Serpell J, Snyder S, Volpi E, Woodson G, Kraimps JL, Hisham AN, International Neural Monitoring Study Group. External branch of the superior laryngeal nerve monitoring during thyroid and parathyroid surgery: International Neural Monitoring Study Group standards guideline statement. Laryngoscope. 2013;123 Suppl 4:S1–14.

    Article  PubMed  Google Scholar 

  7. Darr EA, Tufano RP, Ozdemir S, Kamani D, Hurwitz S, Randolph G. Superior laryngeal nerve quantitative intraoperative monitoring is possible in all thyroid surgeries. Laryngoscope. 2014;124:1035–41.

    Article  PubMed  Google Scholar 

  8. Bellantone R, Boscherini M, Lombardi CP, Bossola M, Rubino F, De Crea C, Alesina P, Traini E, Cozza T, D'alatri L. Is the identification of the external branch of the superior laryngeal nerve mandatory in thyroid operation? Results of a prospective randomized study. Surgery. 2001;130:1055–9.

    Article  CAS  PubMed  Google Scholar 

  9. Adour KK, Schneider GD, Hilsinger Jr RL. Acute superior laryngeal nerve palsy: analysis of 78 cases. Otolaryngol Head Neck Surg. 1980;88:418–24.

    Article  CAS  PubMed  Google Scholar 

  10. Barczyński M, Konturek A, Stopa M, Honowska A, Nowak W. Randomized controlled trial of visualization versus neuromonitoring of the external branch of the superior laryngeal nerve during thyroidectomy. World J Surg. 2012;36:1340–7.

    Article  PubMed  PubMed Central  Google Scholar 

  11. Cernea C, Ferraz AR, Nishio S, Dutra Jr A, Hojaij FC, dos Santos LR. Surgical anatomy of the external branch of the superior laryngeal nerve. Head Neck. 1992;14:380–3.

    Article  CAS  PubMed  Google Scholar 

  12. Friedman M, Toriumi D. Functional identification of the external laryngeal nerve during thyroidectomy. Laryngoscope. 1986;96:1291–2.

    CAS  PubMed  Google Scholar 

  13. Dionigi G, Boni L, Rovera F, Bacuzzi A, Dionigi R. Neuromonitoring and video-assisted thyroidectomy: a prospective, randomized case-control evaluation. Surg Endosc. 2009;23:996–1003.

    Article  PubMed  Google Scholar 

  14. Lifante JC, McGill J, Murry T, Aviv JE, Inabnet 3rd WB. A prospective, randomized trial of nerve monitoring of the external branch of the superior laryngeal nerve during thyroidectomy under local/regional anesthesia and IV sedation. Surgery. 2009;146:1167–73.

    Article  PubMed  Google Scholar 

  15. Aina EN, Hisham AN. External laryngeal nerve in thyroid surgery: recognition and surgical implications. ANZ J Surg. 2001;71:212–4.

    Article  CAS  PubMed  Google Scholar 

  16. Jonas J, Bähr R. Neuromonitoring of the external branch of the superior laryngeal nerve during thyroid surgery. Am J Surg. 2000;179:234–6.

    Article  CAS  PubMed  Google Scholar 

  17. Inabnet WB, Murry T, Dhiman S. Neuromonitoring of the external branch of the superior laryngeal nerve during minimally invasive thyroid surgery under local anesthesia: a prospective study of 10 patients. Laryngoscope. 2009;119:597–601.

    Article  PubMed  Google Scholar 

  18. Pagedar NA, Freeman JL. Identification of the external branch of the superior laryngeal nerve during thyroidectomy. Arch Otolaryngol Head Neck Surg. 2009;135:360–2.

    Article  PubMed  Google Scholar 

  19. Lennquist S, Cahlin C, Smeds S. The superior laryngeal nerve in thyroid surgery. Surgery. 1987;102:999–1008.

    CAS  PubMed  Google Scholar 

  20. Friedman M, Wilson MN, Ibrahim H. Superior laryngeal nerve identification and preservation in thyroidectomy. Oper Technol Otolaryngol. 2009;20:145–51.

    Article  Google Scholar 

  21. Selvan B, Babu S, Paul MJ, Abraham D, Samuel P, Nair A. Mapping the compound muscle action potentials of cricothyroid muscle using electromyography in thyroid operations: a novel method to clinically type the external branch of the superior laryngeal nerve. Ann Surg. 2009;250:293–300.

    Article  PubMed  Google Scholar 

  22. Furlan JC, Cordeiro AC, Brandão LG. Study of some “intrinsic risk factors” that can enhance an iatrogenic injury of the external branch of the superior laryngeal nerve. Otolaryngol Head Neck Surg. 2003;128:396–400.

    Article  PubMed  Google Scholar 

  23. Masuoka H, Miyauchi A, Higashiyama T, Yabuta T, Fukushima M, Ito Y, Kihara M, Kobayashi K, Yamada O, Nakayama A, Miya A. Prospective randomized study on injury of the external branch of the superior laryngeal nerve during thyroidectomy comparing intraoperative nerve monitoring and a conventional technique. Head Neck. 2014. doi:10.1002/hed.23778.

    PubMed  Google Scholar 

  24. Randolph GW. SLN monitoring (in chapter 33). In: Randolph GW, editor. Surgery of the thyroid and parathyroid glands. 2nd ed. Philadelphia: Elsevier; 2012. p. 339.

    Google Scholar 

  25. Potenza AS, Phelan EA, Cernea CR, Slough CM, Kamani DV, Darr A, Zurakowski D, Randolph GW. Normative intra-operative electrophysiologic waveform analysis of superior laryngeal nerve external branch and recurrent laryngeal nerve in patients undergoing thyroid surgery. World J Surg. 2013;37:2336–42.

    Article  PubMed  Google Scholar 

  26. Maranillo E, León X, Quer M, Orús C, Sañudo JR. Is the external laryngeal nerve an exclusively motor nerve? The cricothyroid connection branch. Laryngoscope. 2003;113:525–9.

    Article  PubMed  Google Scholar 

  27. Morton RP, Whitfield P, Al-Ali S. Anatomical and surgical considerations of the external branch of the superior laryngeal nerve: a systematic review. Clin Otolaryngol. 2006;31:368–74.

    Article  CAS  PubMed  Google Scholar 

  28. Kochilas X, Bibas A, Xenellis J, Anagnostopoulou S. Surgical anatomy of the external branch of the superior laryngeal nerve and its clinical significance in head and neck surgery. Clin Anat. 2008;21:99–105.

    Article  PubMed  Google Scholar 

  29. Masuoka H, Miyauchi A, Yabuta T, Fukushima M, Miya A. Innervation of the cricothyroid muscle by the recurrent laryngeal nerve. Head Neck. 2015. doi:10.1002/hed.24015.

    Google Scholar 

  30. Rossi RL, Cady B, Silverman ML, Wool MS, Horner TA. Current trends of conservative surgery for differentiated thyroid carcinoma. World J Surg. 1986;10:612–22.

    Article  CAS  PubMed  Google Scholar 

  31. Aluffi P, Policarpo M, Cherovac C, Olina M, Dosdegani R, Pia F. Post-thyroidectomy superior laryngeal nerve injury. Eur Arch Otorhinolaryngol. 2001;258:451–4.

    Article  CAS  PubMed  Google Scholar 

  32. Loré Jr JM, Kokocharov SI, Kaufman S, Richmond A, Sundquist N. Thirty-eight-year evaluation of a surgical technique to protect the external branch of the superior laryngeal nerve during thyroidectomy. Ann Otol Rhinol Laryngol. 1998;107:1015–22.

    Article  PubMed  Google Scholar 

  33. Kark AE, Kissin MW, Auerbach R, Meikle M. Voice changes after thyroidectomy: role of the external laryngeal nerve. Br Med J (Clin Res Ed). 1984;289:1412–5.

    Article  CAS  Google Scholar 

  34. Reeve TS, Coupland GA, Johnson DC, Buddee FW. The recurrent and external laryngeal nerves in thyroidectomy. Med J Aust. 1969;22:380–2.

    Google Scholar 

  35. El-Kashlan HK, Carroll WR, Hogikyan ND, Chepeha DB, Kileny PR, Esclamado RM. Selective cricothyroid muscle reinnervation by muscle-nerve-muscle neurotization. Arch Otolaryngol Head Neck Surg. 2001;127:1211–5.

    Article  CAS  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Endocrine Surgery, Jagiellonian University Medical College, 37 Pradnicka Street, Krakow, 31-202, Poland

    Marcin Barczyński M.D., Ph.D.

  2. The Claire and John Bertucci Endowed Chair in Thyroid Surgery Oncology, Harvard Medical School, Boston, MA, USA

    Gregory W. Randolph M.D.

  3. Division of Thyroid and Parathyroid Endocrine Surgery, Department of Otolaryngology—Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Boston, MA, USA

    Gregory W. Randolph M.D.

  4. Department of Surgery, Endocrine Surgery Service, Massachusetts General Hospital, Boston, MA, USA

    Gregory W. Randolph M.D.

Authors
  1. Marcin Barczyński M.D., Ph.D.
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Gregory W. Randolph M.D.
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Marcin Barczyński M.D., Ph.D. .

Editor information

Editors and Affiliations

  1. The Claire and John Bertucci Endowed Cha, Harvard Medical School, Boston, Massachusetts, USA

    Gregory W. Randolph

Electronic Supplementary Material

Below is the link to the electronic supplementary material.

The cricothyroid muscle twitch is observed in response to the EBSLN stimulation in all patients (WMV 12161 kb)

Rights and permissions

Reprints and permissions

Copyright information

© 2016 Springer International Publishing Switzerland

About this chapter

Cite this chapter

Barczyński, M., Randolph, G.W. (2016). Surgical Approach and Monitoring of the External Branch of the Superior Laryngeal Nerve (EBSLN). In: Randolph, G. (eds) The Recurrent and Superior Laryngeal Nerves. Springer, Cham. https://doi.org/10.1007/978-3-319-27727-1_17

Download citation

  • DOI: https://doi.org/10.1007/978-3-319-27727-1_17

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-319-27725-7

  • Online ISBN: 978-3-319-27727-1

  • eBook Packages: MedicineMedicine (R0)

Publish with us

Policies and ethics

Search

Navigation