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Anatomical variations of the external branch of the superior laryngeal nerve in relation to the inferior constrictor muscle: cadaveric dissection study

Published online by Cambridge University Press:  12 July 2012

U Patnaik ,
A Nilakantan  and
T Shrivastava
U Patnaik*
Affiliation:
Department of ENT, Base Hospital and Army College of Medical Sciences, New Delhi, India
A Nilakantan
Affiliation:
Department of ENT, Base Hospital and Army College of Medical Sciences, New Delhi, India
T Shrivastava
Affiliation:
Department of Anatomy, Base Hospital and Army College of Medical Sciences, New Delhi, India
*
Address for correspondence: Dr U Patnaik, Department of ENT, Base Hospital and Army College of Medical Sciences, Delhi Cantonment, New Delhi 110010, India Fax: +91 (0)112 333 7002 E-mail: umi75pat@gmail.com
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Abstract

Objectives:

To determine anatomical variations in the external branch of the superior laryngeal nerve in relation to the inferior constrictor muscle, and to propose a rational approach for the preservation of the nerve in thyroid surgery based on anatomical principles.

Method:

A cadaveric dissection study of the anatomy of the external branch of the superior laryngeal nerve in relation to the inferior constrictor muscle was conducted. Twenty-nine formalin-fixed cadavers of both sexes (age 50–70 years), with normal necks, were examined.

Results:

In relation to the Friedman classification, three anatomical variations of the external branch of the superior laryngeal nerve were found. Type 1 variation was found in 57.1 per cent of cases, type 2 in 26.8 per cent and type 3 in 16 per cent.

Conclusion:

The prevalence of type 3 variation of the external branch of the superior laryngeal nerve suggests that the nerve will not be encountered in a certain percentage of individuals as it lies under the cover of the inferior constrictor. Therefore, there is no justification for attempting to identify the nerve in all cases.

Keywords

Laryngeal Nerve, SuperiorThyroidectomyCricothyroid MusclePharyngeal Muscles
Type
Main Articles
Information
The Journal of Laryngology & Otology , Volume 126 , Issue 9 , September 2012 , pp. 907 - 912
Copyright
Copyright © JLO (1984) Limited 2012

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References

1Roy, AD, Gardiner, RH, Niblock, WM. Thyroidectomy and the recurrent laryngeal nerves. Lancet 1956;270:988–90Google Scholar
2Borley, NR, Healey, JC, Collins, P, Johnson, D, Crossman, AR, Mahadevan, V et al. Neck. In: Standring, S, ed. Gray's Anatomy, 40th edn.London: Elsevier, 2008;435–66Google Scholar
3Perry, A. Speech therapy in ENT practice: scope, science and evidence for intervention. In: Gleeson, M, ed. Scott-Brown's Otolaryngology, Head and Neck Surgery, 7th edn.Great Britain: Hodder Arnold, 2008;2216–33Google Scholar
4Jansson, S, Tisell, L, Hagne, I, Sanner, E, Stenborg, R, Svensson, P. Partial SLN lesions before and after thyroid surgery. World J Surg 1988;12:522–7CrossRefGoogle ScholarPubMed
5Friedman, M, Lo Savio, P, Ibrahim, H. Superior laryngeal nerve identification and preservation in thyroidectomy. Arch Otolaryngol Head Neck Surg 2002;128:296–303Google Scholar
6Cernea, CR, Nishio, S, Hojaji, FC. Identification of the EBSLN in large goiters. Am J Otolaryngol 1995;16:307–11Google Scholar
7Kierner, AC, Aigner, M, Burian, M. The external branch of the superior laryngeal nerve: its topographical anatomy as related to surgery of the neck. Arch Otolaryngol Head Neck Surg 1998;124:301–3Google Scholar
8Lore, JM, Kokocharov, SI, Kaufman, S, Richmond, A, Sundquist, N. 38-year evaluation of a surgical technique to protect the EBSLN during thyroidectomy. Ann Otol Rhinol Laryngol 1998;107:1015–22CrossRefGoogle Scholar
9Kark, AE, Kissin, MW, Auerbach, R, Meikle, M. Voice changes after thyroidectomy: role of the external laryngeal nerve. BMJ 1984;289:1412–15CrossRefGoogle ScholarPubMed
10Cernea, C, Ferraz, AR, Furlani, J, Nishio, S, Hojaij, FC, Dutra, A et al. Identification of the external branch of the superior laryngeal nerve during thyroidectomy. Am J Surg 1992;164:634–9Google Scholar
11Choksy, SA, Nicholson, ML. Prevention of voice changes in singers by using a nerve stimulator to identify the external laryngeal nerve. Br J Surg 1996;83:1131–2Google Scholar
12Lore, JM, Kim, DJ, Elias, S. Preservation of the laryngeal nerves during total thyroid lobectomy. Ann Otol Rhinol Laryngol 1977;86:777–88CrossRefGoogle ScholarPubMed
13Jonas, J, Bahr, R. Neuromonitoring of the EBSLN during thyroid surgery. Am J Surg 2000;179:234–6CrossRefGoogle ScholarPubMed
14Teitelbaum, BJ, Wenig, BL. Superior laryngeal nerve injury from thyroid surgery. Head Neck 1995;17:36–40Google Scholar
15Lekacos, NL, Miligos, ND, Tzaedis, PJ, Majiatis, S, Patoulis, J. The SLN in thyroidectomy. Am Surg 1987;53:610–12Google Scholar
16Moran, RE, Castro, AF. The superior laryngeal nerve in thyroid surgery. Ann Surg 1951;134:1018–21Google Scholar
17Arnold, GE. Vocal rehabilitation of paralytic dysphonia. Arch Otolaryngol Head Neck Surg 1962;76:358–68CrossRefGoogle ScholarPubMed
18Hong, KH, Kim, YK. Phonatory characteristics of patients undergoing thyroidectomy without laryngeal nerve injury. Otolaryngol Head Neck Surg 1997;117:399–404Google Scholar
19Lennquist, S, Cahlin, C, Smeds, S. The superior laryngeal nerve in thyroid surgery. Surgery 1987;107:1015–22Google Scholar
20Shah, JP, Patel, SG. Thyroid and parathyroid glands. In: Shah, JP, ed. Head and Neck Surgery and Oncology, 3rd edn.London: Elsevier, 2005;395–437Google Scholar