open access
Variability in the anterior extralaryngeal branch of the recurrent laryngeal nerve: clinical implications
open access
Abstract
Background: This study aimed to identify the anterior and posterior extralaryngeal branches (AELB, PELB) of the recurrent laryngeal nerve (RLN), measure these branches when present, and determine relationships between gender, sidedness and neck length.
Materials and methods: Dissection was completed to level of the thyroid on 45 cadavers. The course of the RLN was then traced superiorly from its entry into the neck. Careful reflection of the thyroid and dissection of the lateral thyroid ligament permitted visualisation of the full course of the nerve. If extralaryngeal branching (ELB) was present, measurements were taken from the point of bifurcation of the RLN to the point of laryngeal entry through the cricothyroid membrane. Neck measurements, from the spinous process of C7 to the superior nuchal line, were taken. Gender of the specimen was noted. Data was analysed in SPSS.
Results: Extralaryngeal branching was found in 77.78% of our sample, 77.14% on the left and 54.29% on the right. A significant difference was found between AELB length on the left and right, indicating that the left branch will be longer than the right when present. A significant difference in neck length between those with and without ELB was also found, indicating that people with longer necks more often display ELB. Neither neck length and AELB length, nor gender and AELB length were strongly correlated in this sample.
Conclusions: Extralaryngeal branching can occur in all populations, but there are definite trends in its incidence and length. Surgeons should be aware of these trends before operating on patients.
Abstract
Background: This study aimed to identify the anterior and posterior extralaryngeal branches (AELB, PELB) of the recurrent laryngeal nerve (RLN), measure these branches when present, and determine relationships between gender, sidedness and neck length.
Materials and methods: Dissection was completed to level of the thyroid on 45 cadavers. The course of the RLN was then traced superiorly from its entry into the neck. Careful reflection of the thyroid and dissection of the lateral thyroid ligament permitted visualisation of the full course of the nerve. If extralaryngeal branching (ELB) was present, measurements were taken from the point of bifurcation of the RLN to the point of laryngeal entry through the cricothyroid membrane. Neck measurements, from the spinous process of C7 to the superior nuchal line, were taken. Gender of the specimen was noted. Data was analysed in SPSS.
Results: Extralaryngeal branching was found in 77.78% of our sample, 77.14% on the left and 54.29% on the right. A significant difference was found between AELB length on the left and right, indicating that the left branch will be longer than the right when present. A significant difference in neck length between those with and without ELB was also found, indicating that people with longer necks more often display ELB. Neither neck length and AELB length, nor gender and AELB length were strongly correlated in this sample.
Conclusions: Extralaryngeal branching can occur in all populations, but there are definite trends in its incidence and length. Surgeons should be aware of these trends before operating on patients.
Keywords
anterior extralaryngeal branch, posterior extralaryngeal branch, recurrent laryngeal nerve
About this articleTitle
Variability in the anterior extralaryngeal branch of the recurrent laryngeal nerve: clinical implications
Journal
Issue
Article type
Original article
Pages
44-50
Published online
2016-08-22
Page views
1098
Article views/downloads
952
DOI
Pubmed
Bibliographic record
Folia Morphol 2017;76(1):44-50.
Keywords
anterior extralaryngeal branch
posterior extralaryngeal branch
recurrent laryngeal nerve
Authors
K. Hessel
E. Wessel
A. Olinger
B. W. Wright
References (23)- Beneragama T, Serpell JW. Extralaryngeal bifurcation of the recurrent laryngeal nerve: a common variation. ANZ J Surg. 2006; 76(10): 928–931.
- Cakir BO, Ercan I, Sam B, et al. Reliable surgical landmarks for the identification of the recurrent laryngeal nerve. Otolaryngol Head Neck Surg. 2006; 135(2): 299–302.
- Casella C, Pata G, Nascimbeni R, et al. Does extralaryngeal branching have an impact on the rate of postoperative transient or permanent recurrent laryngeal nerve palsy? World J Surg. 2009; 33(2): 261–265.
- Cernea CR, Hojaij FC, De Carlucci D, et al. Recurrent laryngeal nerve: a plexus rather than a nerve? Arch. Otolaryngol. Head Neck Surg. 2009; 135(11): 1098–1102.
- Chiang FY, Lu IC, Chen HC, et al. Anatomical variations of recurrent laryngeal nerve during thyroid surgery: how to identify and handle the variations with intraoperative neuromonitoring. Kaohsiung J. Med. Sci. 2010; 26(11): 575–583.
- Eckel HE, Sittel C, Zorowka P, et al. Dimensions of the laryngeal framework in adults. Surg Radiol Anat. 1994; 16(1): 31–36.
- Gregg RL. Avoiding injury to the extralaryngeal nerves. Ann. Otol. Rhinol. Laryngol. 1957; 66(3): 656–678.
- Kahane JC. Growth of the human prepubertal and pubertal larynx. J Speech Hear Res. 1982; 25(3): 446–455.
- Kandil E, Abdel Khalek M, Aslam R, et al. Recurrent laryngeal nerve: significance of the anterior extralaryngeal branch. Surgery. 2011; 149(6): 820–824.
- Kandil E, Abdelghani S, Friedlander P, et al. Motor and sensory branching of the recurrent laryngeal nerve in thyroid surgery. Surgery. 2011; 150(6): 1222–1227.
- Katz AD. Extralaryngeal division of the recurrent laryngeal nerve. Report on 400 patients and the 721 nerves measured. Am. J. Surg. 1986; 152(4): 407–410.
- Katz AD, Nemiroff P. Anastamoses and bifurcations of the recurrent laryngeal nerve--report of 1177 nerves visualized. Am Surg. 1993; 59(3): 188–191.
- Maranillo E, Leon X, Orus C, et al. Variability in nerve patterns of the adductor muscle group supplied by the recurrent laryngeal nerve. Laryngoscope. 2005; 115(2): 358–362.
- Maue WM, Dickson DR. Cartilages and ligaments of the adult human larynx. Arch Otolaryngol. 1971; 94(5): 432–439.
- Morrison LF. Recurrent laryngeal nerve paralysis; a revised conception based on the dissection of one hundred cadavers. Ann. Otol. Rhinol. Laryngol. 1952; 61(2): 567–592.
- Nemiroff PM, Katz AD. Extralaryngeal divisions of the recurrent laryngeal nerve. Surgical and clinical significance. Am. J. Surg. 1982; 144(4): 466–469.
- Nguyen M, Junien-Lavillauroy C, Faure C. Anatomical intra-laryngeal anterior branch study of the recurrent (inferior) laryngeal nerve. Surg Radiol Anat. 1989; 11(2): 123–127.
- Serpell JW, Yeung MJ, Grodski S. The motor fibers of the recurrent laryngeal nerve are located in the anterior extralaryngeal branch. Ann. Surg. 2009; 249(4): 648–652.
- Steinberg JL, Khane GJ, Fernandes CM, et al. Anatomy of the recurrent laryngeal nerve: a redescription. J Laryngol Otol. 1986; 100(8): 919–927.
- Sunderland S, Swaney WE. The intraneural topography of the recurrent laryngeal nerve in man. Anat. Rec. 1952; 114(3): 411–426.
- Wafae N, Vieira MC, Vorobieff A. The recurrent laryngeal nerve in relation to the inferior constrictor muscle of the pharynx. Laryngoscope. 1991; 101(10): 1091–1093.
- Williams AF. The recurrent laryngeal nerve and the thyroid gland. J Laryngol Otol. 1954; 68(11): 719–725.
- Yalçin B, Ozan H. Extralaryngeal bifurcation of the recurrent laryngeal nerve. ANZ J Surg. 2007; 77(4): 306.
