scholarly journals Relation of the external branch of the superior laryngeal nerve to the superior pole of the thyroid gland: An anatomical study

2007 ◽  
Vol 20 (5) ◽  
pp. 516-520 ◽  
Author(s):  
D. Naidoo ◽  
J.M. Boon ◽  
C.J. Mieny ◽  
P.J. Becker ◽  
A.-N. van Schoor
2013 ◽  
Vol 3 (2) ◽  
pp. 39-41 ◽  
Author(s):  
Bhagyashree D Bokare ◽  
Poorva K Athavale ◽  
Vipin R Ekhar ◽  
Devendra Meghraj Mahore

ABSTRACT The basic principle of head and neck surgery is based on the identification and preservation of important structures, rather than avoidance. This principle is also applicable to identification and preservation of external branch of the superior laryngeal nerve (EBSLN) as a standard routine in all thyroid surgeries. During thyroid surgery, the EBSLN is clearly at risk due to its close proximity to the superior thyroid artery (STA) and its branches that need to be ligated during dissection of the superior pole of the thyroid gland. Injury is detrimental to the patient by causing paralysis of the cricothyroid muscle which is the main tensor and pitch controlling mechanism of the vocal folds. Injury to the EBSLN during surgery can result in the voice changes, loss of upper range and easy fatigability of voice, the severity of which varies according to the vocal demand of the patient. Total 45 cases of thyroid swellings were treated with surgery, in the Department of ENT at a tertiary care hospital during the period from 1st October 2009 to 30th October 2010. Hemithyroidectomy was the most common operative procedure implemented in 24 patients (53.33%) in which right sided was common. Next common procedure performed was that of total thyroidectomy in 14 patients (31.11%). Four patients underwent total thyroidectomy with neck dissection. The position of EBSLN was classified according the Cernea et al classification. In our study we found the EBSLN to be type I in 46.66%, type IIa in 73.33% and type IIb in 02.22%. The anatomical landmark taken into consideration to identify EBSLN was the Joll's triangle with its relation to the superior pole of the thyroid gland and STA. How to cite this article Athavale PK, Bokare BD, Ekhar VR, Mahore DM. Identification and Preservation of External Branch of Superior Laryngeal Nerve in Thyroidectomy. Int J Phonosurg Laryngol 2013;3(2):39-41.


2020 ◽  
Vol 6 (2) ◽  
pp. 73-76
Author(s):  
Anurag ◽  
Vishnu Gupta

Background: The thyroid gland is essential for normal growth of the body. This study assessed relation of external branch of superior laryngeal nerve to the superior pole of the thyroid gland. Subjects and Methods: This study was conducted on 25 human cadavers having 50 superior thyroid poles of both genders. Cadavers were classified based on age groups, group I was those with age less than 39 years and group II cadavers were those with age more than 40 years of age. Various measurements were performed on cadavers. Results: 14 cadavers were I group I and 11 were in group II. The mean mass was 67.2 Kgs in group I and 59.5 Kgs in group II, time elapsed after death was 481.5 minutes in group I and 476.4 minutes in group II, mean height was 1.74 meters in group I and 1.69 meters in group II, mean BMI found to be 22.3 kg/m2in group I and 20.1 kg/m2in group II. Height found to be significant between both groups (P< 0.05). The mean distance from EBSLN to cranial point of the thyroid gland was 6.66 mm in group I and 8.96 mm in group II. The mean transverse distance from superior thyroid artery to EBSLN was 3.55 mm in group I and 5.12 mm side in group II. The mean distance of the crossing point between the most cranial point of the thyroid lobe was 6.40 mm in group I and 11.47 mm in group II. The mean distance from the EBSLN to the midline of the neck was 19.80 mm in group I and 18.58 mm in group II. The mean distance from the EBSLN to the midline of the neck on the most cranial point of the cricoid cartilage was 18.77 mm in group I and 17.80 mm in group II. Conclusion: Authors found variation in measurements in left and right side in both group I and group II.


2003 ◽  
Vol 128 (3) ◽  
pp. 396-400 ◽  
Author(s):  
Julio Cesar Furlan ◽  
Anói Castro Cordeiro ◽  
Lenine Garcia Brandã

OBJECTIVE: This study evaluates some “intrinsic risk factors” for a surgical injury of the external branch of superior laryngeal nerve (EBSLN) based on its anatomic relationship with the thyroid gland. STUDY DESIGN AND SETTING: Seventy-two neck dissections were performed in 36 fresh human adult cadavers. Every EBSLN was dissected and categorized using Cernea's classification. All data regarding gender, ethnicity, stature, side of the neck, and volume of hemi thyroid were collected and statistically analyzed by the χ 2 –test and analysis of variance. RESULTS: Although no statistical differences were observed between genders ( P = 0.3770), ethnicities ( P = 0.9780) or sides of the neck ( P = 0.2523), statistical significance was reached regarding the nerve type when the groups were divided by stature ( P = 0.0006) and glandular volume ( P = 0.0007). CONCLUSION: Individual stature and volume of the hemi thyroid gland are probably involved in risk of the surgical EBSLN injury. SIGNIFICANCE: Surgeons should be aware of these anatomic findings in order to obtain a good voice-related outcome in the thyroidectomies.


Author(s):  
Vipin R. Ekhar ◽  
Ramkumar V. ◽  
Ritesh N. Shelkar ◽  
Akshay V. Sarode

<p class="abstract"><strong>Background:</strong> Identification of external branch of superior laryngeal nerve (EBSLN) according to Cernea et al classification and to describe a surgical technique of superior pole dissection to preserve EBSLN during thyroid surgeries.</p><p class="abstract"><strong>Methods:</strong> The study was done over 2 years period in a tertiary care hospital. 105 nerves were studied among the 90 patients who underwent thyroid surgeries. Avascular dissection over the JOLL’S triangle was carried out and identified EBSLN were classified according to Cernea et al classification. Individual ligation of superior pole vessels was carried out after identifying the nerve. Outcome was studied relating the identified nerve with sides of thyroidectomy performed, size of thyroid gland and nerves at risk according to Cernea et al classification.  </p><p class="abstract"><strong>Results:</strong> Of the 105 nerves studied, in 81.90% of patients the nerve was identified. There were 34.88% of Type 1 nerves, 52.33% of Type 2A nerve and 12.79% of Type 2B nerves identified. Less number of nerves could be identified on the left side. Type 2B nerves were more common on left side inspite of less number of dissections carried out on left. Type 2 variation was more common in large goiters.</p><p><strong>Conclusions:</strong> Careful dissection should be done in superior pole in avascular cricothyroid space, with lateralization of superior pole and individual identification of superior pole vessels once the nerve is identified. Identification of the nerve is mandatory in all patients who undergo thyroid surgery for optimal functions of the larynx. These results showed a better identification of nerves by proper surgical techniques without use of any sophisticated equipments. </p>


2019 ◽  
Vol 21 (1) ◽  
pp. 84-88
Author(s):  
V Y Malyuga ◽  
A A Kuprin

Till now, there is no universal clinical classification about variations of the external branch of the superior laryngeal nerve despite the multiple classifications that was proposed. The aim of this research is identification and systematization of topographic types of the external branch of the superior laryngeal nerve. The study is based on the autopsy material (21 complexes organs of the neck) and on identification of variations of 40 external branches of the superior laryngeal nerve. We identify two permanent landmark that are located at the minimum distance from nerve and on which we made metrical calculations: oblique line of thyroid cartilage, tendinous arch of the inferior pharyngeal constrictor muscle. The “entry” point of the nerve is always located on the inferior pharyngeal constrictor muscle,and not protruding beyond the oblique line of thyroid cartilage superiorly and tendinous arch of the inferior pharyngeal constrictor muscle anteriorly. The proposed topographic classification of the location of the external branch of the superior laryngeal nerve is based on localization of point of pierced of the nerve relating to the length of the oblique line of thyroid cartilage. In 64.2% of cases, the external branch of the superior laryngeal nerve was in close proximity to the upper pole of the thyroid gland, which could lead to its damage during surgery (type I and II). In type III and IV (35.8%) - the point of "entry" in the muscle was located as far as possible from the upper pole of the thyroid gland, and most of the nerve was covered by the fibers of the inferior pharyngeal constrictor muscle.


Author(s):  
Sunil Samdani ◽  
Shweta Dudi ◽  
Veena Mobarsa

<p class="abstract"><strong>Background:</strong> The external branch of the superior laryngeal nerve innervates the cricothyroid muscle to promote lengthening and thinning of the vocal fold, thus increasing voice pitch. The close relation with the superior thyroid vessels puts the external branch of the superior laryngeal nerve in risk every time the superior pole of the thyroid is dissected.</p><p class="abstract"><strong>Methods:</strong> : This randomized  controlled  study was undertaken at SMS Medical College, Jaipur between  February  2013 to November 2014  to  evaluate  the  impact  of  isolating  and  ligating  the  superior  thyroid  vessels  near  the  upper pole of the gland as compared  to conventional mass  ligation  of  the  superior  pole  regarding  external branch of superior laryngeal nerve injury in hemi or  subtotal  thyroidectomy. Total 120 patients were taken and divided into two groups A and B. Group A including mass ligation of superior pole of thyroid and group B includes individual ligation of superior thyroid vessels.  </p><p class="abstract"><strong>Results:</strong> Our study observed normal voice in 51 cases (85%) in individual ligation of superior thyroid vessel group and 27 cases (45%) in mass ligation group on auditory perceptual test by GRBAS scale one month postoperatively. Normal electromyography findings after 1 month post-operatively was observed in 57 cases (95%) in individual ligation group as compared to 40 cases (66.67%) in mass ligation group.</p><p class="abstract"><strong>Conclusions:</strong> Our study conclude that careful ligation of superior thyroid vessels is a safe technique to preserve the external branch of superior laryngeal nerve than mass ligation of superior pole of thyroid.</p>


Folia Medica ◽  
2018 ◽  
Vol 60 (1) ◽  
pp. 154-157 ◽  
Author(s):  
Lyubka Aleksova ◽  
Metin M. Ali ◽  
Djevdet I. Chakarov ◽  
Zeynep M. Yozgyur

Abstract Aim: To compare the level of intra-operative identification of external branch of the superior laryngeal nerve (EBSLN) through classical conventional clinical methods of prevention against those applying intraoperative neuromonitoring (IONM). Materials and methods: The study included 102 patients with interventions on the thyroid gland performed in the surgical clinics of St George University Hospital and the Department of Special Surgery of Plovdiv Medical University. All operative procedures were performed by the standard technique of capsular dissection and IONM. Results: Of all 102 thyroid procedures 87 (85.3%) patients underwent total thyroidectomy and 15 (14.7%) had unilateral thyroid lobectomy. One hundred fifty-five (82.01%) out of 189 expected EBSLN were identified and investigated intraoperatively when trying to identify visually EBSLN by the so called classical (conventional) methods of prevention. With the use of IONM, 181 (96.76%) EBSLN were correctly identified. Compared to the preliminary results of visual identification - 155/189 (82.01%) EBSLN, the degree of identification of EBSLN through IONM reached 96.76% which is a statistically significant difference (P <0.05) Conclusion: The use of IONM during thyroid resection significantly improves the degree of identification of EBSLN compared to conventional means of prevention. Routine use of IONM in surgical interventions on the thyroid gland will be beneficial for more secure identification and prevention of EBSLN.


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