Variations in the course of the externalbranch of the superior laryngeal nerveand their importance in surgicalprocedures: an experimental cadaveric study.

<br><b>Introduction:</b> Injury of the external branch of the superior laryngeal nerve can cause a hoarse or weak voice due to the functional loss (dysergia) of the cricothyroid muscle. Defining the anatomical variations of the external branch of the superior laryngeal nerve and estimating their frequency are crucial for surgical interventions.</br> <br><b>Aim:</b> To reveal the topography of the external branch in the Anatolian population, to prevent injury of it during the surgical intervention in the anterior neck region.</br> <br><b>Material and methods:</b> 26 bilateral hemilarynges (4 females, 22 males) were dissected. The morphometric and morphological features of the external branch were examined. The obtained results were compared statistically, left and right.</br> <br><b>Results:</b> Landmarks such as the thyroid gland and laryngeal prominence were determined for the detection of the external branch. The variations of the course of the external branch and the points of piercing the cricothyroid muscle or inferior pharyngeal constrictor muscle were evaluated.</br> <br><b>Discussion:</b> Although safe approaches have been described for nerve protection during neck surgeries, injuries may occur during preliminary surgery as the mentioned nerve is thinner and more superficial than other branches of the vagus nerve. However, it can be detected more easily and safely by knowing the defined anatomical landmarks and morphological variations of the external branch.</br> <br><b>Conclusion:</b> The anatomical variations described can be a safe and important guide in surgeries of the anterior neck region.</br>.

The prevalence and anatomy of the pyramidal lobe of the thyroid gland: A meta-analysis with implications for thyroid surgery.

The pyramidal lobe (PL), also known as the third lobe of the thyroid gland or lobe of Lalouette is an embryological remnant of the caudal end of the thyroglossal tract. The following meta-analysis aims to provide a detailed analysis of the anatomical variations of the PL using the available data in the literature. Major online medical databases such as PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched in order to find all studies considering the prevalence and anatomy of the PL of the thyroid gland. Finally, a total of 24 studies that met the required criteria and contained complete and relevant data were included in the present meta-analysis. The pooled prevalence of the PL was found to be 42.82% (95% CI: 35.90%-49.89%). An analysis showed that the mean length was 23.09 mm (SE: 0.56). The mean width was found to be 10.59 mm (SE: 0.77). The pooled prevalence of the PL originating from the left lobe (LL) was established at 40.10% (95% CI: 28.83%-51.92%). In conclusion, we believe that this is the most accurate and up-to-date study regarding the complete surgical anatomy of the PL. The PL was prevalent in 42.82% of the cases, being slightly more prevalent in males (40.35%) than females (37.43%). The mean length and width of the PL were 23.09 mm and 10.59 mm, respectively. Our results should be taken into consideration when performing procedures on the thyroid gland, such as thyroidectomies. The presence of the PL can affect the completeness of this procedure and lead to postoperative complications.

Anatomical variations of the superior thyroid artery: A systematic review.

BACKGROUND: The superior thyroid artery (STA) is one of the main arteries that provide blood supply to the thyroid gland. It has a plethora of anatomical variations, and knowledge of its anatomy is necessary in procedures in this area. The aim of this review is to summarize and describe human studies (cadaveric and angiographic) that investigate the anatomical variations related to the STA. MATERIAL AND METHODS: A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A literature search in PubMed, and Embase databases was carried out. Original studies that investigated the origin of the STA and reported data on the variant arterial anatomy were considered, including only cadaveric and angiographic studies. RESULTS: A total of 34 studies (4048 heminecks in total; heminecks in each study: min: 25-max: 1280) were finally included. All studies provide details about sex [men/women ratio median (IQR): 2(1-5)] but none about age and 10 (29%) about nationality. STA morphological characteristics described in the included studies are origin, length, number of branches, distance from the carotid bifurcation and the vessel's diameter. CONCLUSIONS: The STA's anatomical features are subject to a non-negligible degree of variability. Our results should improve the awareness of anatomical variations of the STA, and eventually have an impact on the interventions regarding the visceral compartment of the neck in clinical practice.

Variations of the external branch of the superior laryngeal nerve during its course and its importance in surgical approaches: an experimental cadaveric study.

INTRODUCTION: Injury of the external branch of the superior laryngeal nerve can cause a hoarse or weak voice due to the functional loss (dysergia) of the cricothyroid muscle. Defining the anatomical variations of the external branch of the superior laryngeal nerve and estimating the frequency of it, it makes crucial for surgical interventions. AIM: To reveal the topography of the external branch in the Anatolian population, to prevent injury of it during the surgical intervention in the anterior neck region. MATERIALS AND METHODS: Twenty-six bilateral hemilarynges (4 females, 22 males) were dissected. The morphometric and morphological features of the external branch were examined. The obtained results were compared statistically left and right. RESULTS: Landmarks such as the thyroid gland and laryngeal prominence were determined for the detection of the external branch. The variations of the course of the external branch and the points of piercing the cricothyroid muscle or inferior constrictor pharyngeal muscle were evaluated. DISCUSSION: Although safe approaches have been described for nerve protection during neck surgeries, it can expose injuries during preliminary surgery approaches as the nerve is thinner and more superficial than other branches of the vagus nerve. However, it can be detected more easily and safely during the surgical approach by knowing the defined anatomical landmarks and morphological variations of the external branch. CONCLUSION: The anatomical variations described can be a safe and important guide in surgical approaches to be applied in the anterior neck region.

Correlación ultrasonográfica entre volumen tiroideo y ti-rads. Estudio prospectivo / Ultrasonographic correlation between thyroid volume and ti-rads. Prospective study

La comunidad científica se ha preocupado por cuantificar el volumen tiroideo según variables como sexo, edad y deficiencias de yodo asociadas, sin embargo, pese al uso globalizado de TI-RADS para estimación de riesgo de malignidad en la patología tiroidea, no existe suficiente información en relación a si el tamaño de la glándula guarda o no relación con esta escala. Objetivo: comparar el Volumen Tiroideo con TI-RADS en pacientes atendidos en la unidad de ecografía diagnóstica del Centro Clínico Naguanagua en el período enero 2022 - enero 2023. Métodos: estudio observacional-descriptivo de nivel comparativo, con diseño transversal y prospectivo. Muestra no probabilística censal, abarcando la totalidad de los pacientes a los cuales se les efectuó ecografía tiroidea en el período establecido. Se efectuó un registro en cuanto a la cuantificación del volumen de: lóbulo tiroideo derecho, lóbulo tiroideo izquierdo y total de tiroides, TI-RADS, edad y sexo del paciente. Se utilizó el estadístico ANOVA y se empleó el programa Statistical® de licencia libre. Resultados: muestra de 126 pacientes, con edad promedio de 51,71 años ± 1,44, mediana de 53 años. Cuando se comparó el Volumen Total de Tiroides con TI-RADS, se constató que el mayor promedio lo registraron aquellos pacientes clasificados como 4B (p <0,05). Conclusión: aun cuando se registran mayores promedios de volumen total glandular en pacientes con hallazgos nodulares, llama la atención que entre los datos registrados existan pacientes con valores muy similares a lo reportado en la literatura como volúmenes normales en presencia de patología nodular tiroidea(AU)

The scientific community has been concerned with quantifying thyroid volume according to variables such as sex, age, and associated iodine deficiencies; however, despite the global use of TI-RADS to estimate the risk of malignancy in thyroid pathologies, there is not enough information in regarding whether or not the size of the gland is related to this scale. Objective: to compare the Thyroid Volume with TI-RADS in patients treated in the diagnostic ultrasound unit of the Naguanagua Clinical Center in the period January 2022 - January 2023. Methods: observational-descriptive study of a comparative level, with a crosssectional and prospective design. Non-probabilistic census sample, covering all the patients who underwent thyroid ultrasound in the established period. A record was made regarding the quantification of the volume of: right thyroid lobe, left thyroid lobe and total thyroid, TI-RADS, age and sex of the patient. The ANOVA statistic was used and the free license Statistical® program was used. Results: sample of 126 patients, mean age 51.71 ± 1.44 years, median 53 years. When the Total Thyroid Volume was compared with TI-RADS, it was found that the highest mean was registered by those patients classified as 4B (p <0.05). Conclusion: even when higher total glandular volume averages are recorded in patients with nodular findings, it is noteworthy that among the recorded data there are patients with values very similar to those reported in the literature as normal volumes in the presence of thyroid nodular pathology(AU)

Photoperiodic modulation of ovarian metabolic, survival, proliferation and gap junction markers in adult golden hamster, Mesocricetus auratus.

Female reproductive physiology is greatly dependent on tight regulation of metabolic and survival factors. Photoperiod regulates female reproductive rhythms but very less information exists explaining whether photoperiod could modulate thyroid hormone homeostasis, metabolic/energy parameters along with survival, proliferation and gap junction proteins in the ovary of a long-day breeder, Mesocricetus auratus. Adult female hamsters were exposed to different photoperiodic regimes i.e., critical photoperiod (CP; 12.5L:11.5D), short photoperiod (SP; 8L:16D) and long photoperiod (LP; 16L:8D) for 12 weeks. LP upregulated thyroidal and gonadal activity as apparent by histoarchitecture, thyroid hormone profile [triiodothyronine (T3), thyroxin (T4) and thyroid stimulating hormone (TSH)], luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol (E2) and progesterone (P4) levels when compared with SP exposed hamsters. Further, LP increased thyroid hormone receptor-α/deiodinase-2 (TRα/Dio-2), estrogen receptor-α (ERα)/aromatase and insulin receptor/glucose transporter-4 (IR/GLUT-4) expressions in ovary. Interestingly, ovarian sirtuin-1 (SIRT-1) expression was also upregulated under LP condition along with cell proliferation (proliferating cell nuclear antigen or PCNA), survival (B cell lymphoma-2 or Bcl-2) and gap junction (connexin-43) markers when compared to SP exposed hamsters. We also noted elevated levels of circulatory leptin, insulin along with melatonin and its receptor (MT-1) in ovary under SP condition. Thus, we suggest that photoperiod plays a vital role in regulation of thyroid and reproductive hormone homeostasis along with key metabolic and survival markers in the ovary of adult golden hamsters, M. auratus providing further insight into the regulation of female reproductive seasonality in a long-day breeder.

CT appearance and measurements of the normal thyroid gland in goats.

BACKGROUND: Goats are increasingly being kept as companion animals, thus their owners expect advanced medical care, including modern diagnostic imaging. Computed tomography (CT) is now widely used in veterinary medicine, in both clinical practice and for scientific purposes. So far, the CT appearance of various body parts has been described in goats, but reports on thyroid gland CT are still lacking. The thyroid gland in goats may become enlarged due to dietary, genetic or neoplastic disorders. CT examination, as in other animals and humans, could aid in the diagnosis of thyroid diseases in goats and could be used for research purposes. The aim of the study was to present the CT characteristics of the normal caprine thyroid gland, in particular its dimensions, volume and density. RESULTS: Fifty-seven goats were included in the study. None of the animals had clinical, CT, post-mortem or histopathologic abnormalities in the thyroid gland. CT features of the thyroid gland were determined, such as dimensions, volume, density, location and shape. The presence of the thyroid isthmus and ectopic thyroid tissue was also assessed. The gland was visible in every animal as two homogenous, highly attenuating, well-circumscribed lobes located in the most cranial part of the trachea. The mean dimensions of the thyroid lobe were 30.3 × 12.7 × 6.7 mm, the mean density was 80.9 Hounsfield Units (HU) and the mean volume was 1.32 cm3 or 1.39 cm3, depending on the method used. Also, the internal parathyroid glands were visible in some animals. CONCLUSIONS: For the first time, the normal CT appearance of the thyroid gland has been presented. CT clearly shows the thyroid gland in goats and therefore can be used in clinical practice and for research. The results of the current study may serve as a radiological guideline for practitioners and may be the basis for further CT studies on normal and diseased caprine thyroid glands.

The Relevance of and Surgical Approach to the Suprahyoid Region in Thyroglossal Duct Surgery.

OBJECTIVES: Persistent or recurrent disease following excision of a thyroglossal duct cyst/sinus (TGDC) is often found in the suprahyoid region. Cadaver dissections were performed to identify and name important surgical landmarks in the suprahyoid area; a histopathologic analysis of surgical specimens was completed to determine the incidence and extent of microscopic disease; and clinical outcomes were compared to determine the efficacy of a specific anatomic dissection. STUDY DESIGN: Retrospective case series. METHODS: Standardized dissections of four adult cadavers were performed. Consecutive surgical specimens were examined for evidence of microscopic TDGC disease in the suprahyoid region, measuring the greatest width and length of disease. A retrospective review of all consecutive TGDC procedures was completed. RESULTS: The important surgical landmarks in the suprahyoid area were identified in all cadavers. Microscopic disease in the suprahyoid area was found in 79% (37 of 47) of surgical specimens. The mean greatest length and width of microscopic disease was 12.4 mm and 1.4 mm, respectively. Following identification of these landmarks, the incidence of recurrent or persistent disease decreased (P = .02) from 5% (8 of 159) to 0% (0 of 112). CONCLUSION: The majority of pediatric patients with a TGDC will have microscopic disease in the suprahyoid area. The surgical landmark of the fascial plane between the geniohyoid and genioglossus muscles demarcates the anterior and lateral borders of resection in the suprahyoid area. This approach can be used as a reliable and easily reproducible technique in TGDC surgery to increase confidence of achieving complete removal of disease in the suprahyoid area, avoiding persistent or recurrent disease and a revision procedure. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:553-558, 2021.

Morphometry, topography and arterial supply of the thyroid gland in brazilian shorthair cat

Thyroid gland diseases are the most common endocrinopathies in feline practice. Diagnosis and surgical treatment must base on solid anatomical knowledge about the gland size, localization, and blood supply. However, some textbooks provide a general anatomical description of the thyroid gland of domestic carnivores. Thus, specific details of the feline gland are missing. The present study aimed to investigate the dimensions, topography, and arterial supply of the thyroid gland in Brazilian shorthair cats and, therefore, provide additional data to diagnose and treat feline thyroid diseases. Thirty Brazilian shorthair cats formalin-fixed cadavers (15 male and 15 female) were injected with red-stained latex solution by a canula in the thoracic aorta. The necropsy unit of the Rural Federal University of Rio de Janeiro donated the specimens. The study included only adult animals with no history of thyroid disease. After the fixation period, the cadavers were dissected to investigate the measurements (length, width at cranial and caudal poles, and thickness), topography, and in situ arterial supply of the thyroid lobes. The mean measurements of the length, cranial pole width, caudal pole width, and thickness in the right lobe were 19.39 ± 3.10 mm, 5.36 ± 1.40 mm, 3.67 ± 0.93 mm, and 1.30 ± 0.29 mm, respectively; and 20.29 ± 3.35 mm, 4.85 ± 1.58 mm, 3.88 ± 0.91 mm, 1.64 ± 0.65 mm in the left lobe, respectively. There were no statistical differences (P > 0.05) in the comparison of the measures between sexes or antimers (sides). Pearson's linear correlation detected a positive, moderate (r = 0.55), and significant (P < 0.05) correlation between the right and left lobe lengths. In 70% of the cats, both left and right lobes had the cranial poles located at the same level. Typically, the lobes extended between the first to the eighth tracheal ring. However, the cranial pole of some lobes located as cranially as the cricoid cartilage level, and the caudal pole as caudally as the 12th tracheal ring. Fifty-six percent of the cats had a ventrally located isthmus. In all the sampling, one single thyroid artery emerged as a branch of the common carotid artery and provided branches directly to the thyroid lobe, isthmus and the adjacent muscles and esophagus. Besides establishing average dimensions of normal thyroid lobes in Brazilian shorthair cats, this study detected no significant difference between the average measurements of right and left lobes. Also, a positive linear correlation between the length and width of the right and left lobes became evident. Therefore, the practitioner must consider suspicious any length asymmetry between right and left thyroid lobes until further endocrine test proves otherwise. Most of the cats had the right and left thyroid lobe positioned at the same transversal level; however, positional asymmetries are not uncommon. Unlike dogs, Brazilian shorthair cats have only a single artery to supply each lobe: the thyroid artery. In a feline thyroidectomy, the surgeon must avoid blindly ligating the thyroid artery since this vessel also provided numerous branches to adjacent muscles and esophagus. In a bilateral thyroidectomy, the ventral region between lobes should be thoroughly inspected for the common presence of an isthmus. Sometimes, the surgeon may need to extend the incision caudally beyond the 12th tracheal ring level to visualize the gland tissue entirely.(AU)

Morfometría y vascularización de la glándula tiroides en conejo (Oryctolagus cuniculus) / Morphometry and vascularization of the thyroid glands in rabbits (Oryctolagus cuniculus)

Las glándulas tiroides consisten en dos partes denominadas lobos que se encuentran en ambos lados de la laringe. El objetivo de este estudio fue caracterizar las medidas, topografía y vascularización de la glándula tiroides de conejos Nueva Zelanda. Las disecciones anatómicas se realizaron en 36 cadáveres adultos, 17 machos y 19 hembras, con masa corporal media de 2,5 kg y longitud cara-sacral media de 40 cm. Los cadáveres fueron obtenidos del sector de necropsia de la Universidad. Los especímenes tuvieron la arteria aorta torácica canalada, por la cual se inyectó solución de formaldehído al 10 %, seguida de látex coloreado. En los machos, el lobo izquierdo de la glándula tiroidea midió 1,40 x 0,40 x 0,01 cm y el derecho 1,36 x 0,56 x 0,01 cm; en las hembras, el lobo izquierdo midió 1,50 x 0,49 x 0,01 cm y el derecho 1,37 x 0,48 x 0,01cm. No hubo diferencia significativa (p> 0,05) entre las medias de las medidas entre machos y hembras, pero la extensión del lóbulo izquierdo de las hembras y la anchura del lóbulo derecho de los machos fueran significativamente mayores (p <0,05). La extremidad craneal de los lobos tiroideos se encontraba al nivel del cartílago cricoide en casi todos los especímenes. El extremo caudal presentó topografía más variable, desde el tercer hasta el décimo anillo traqueal, habiendo predominado al nivel del quinto anillo. Invariablemente, la irrigación arterial fue determinada por las arterias tiroideas izquierda y derecha, originadas de la arteria carótida común. Las anastomosis entre las arterias tiroideas fueron comunes. La constancia en las dimensiones y irrigación de la glándula tiroidea puede ser ventajosa en la elección del Coelho como modelo experimental para el estudio de esta glándula.

The thyroid glands consist of two parts called lobes located on both sides of the larynx. The aim of this study was to characterize the measures, topography and arterial irrigation of New Zealand´s rabbits thyroid glands. The anatomical dissections were performed in 36 adult cadavers, 17 males and 19 females, with a mean body mass of 2.5 kg and a mean cranium-sacral length of 40 cm. The specimens were obtained from the necropsy unit of the University. The cadavers had the thoracic aorta artery cannulated, through which 10 % formaldehyde solution was injected, followed by injection colored latex. In males, the left lobe of the thyroid gland measured 1.40x0.40x0.01cm and the right 1.36x0.56x0.01cm; in females, the left lobe measured 1.50x0.49x0.01cm and the right one was 1.37x0.48x0.01cm. There was no significant difference (p> 0.05) between the means of the measurements between males and females, but the left lobe length of the females and the right lobe width of the males were significantly higher (p <0.05). The cranial extremity of the thyroid lobes was at the level of the cricoid cartilage in almost all specimens. The caudal end showed more variable topography, from the third to the tenth tracheal ring in few specimens, but predominated at the level of the fifth ring. Invariably, arterial irrigation was determined by the left and right thyroid arteries, originating from the common carotid artery. Anastomoses between the thyroid arteries were common. The constancy in dimensions and irrigation of the thyroid gland may be advantageous in choosing the rabbit as an experimental model for the study of this gland.

The Tubercle of Zuckerkandl is Associated with Increased Rates of Transient Postoperative Hypocalcemia and Recurrent Laryngeal Nerve Palsy After Total Thyroidectomy.

The current concept of complete resection of thyroid parenchyma shifted the practice from subtotal thyroidectomy to total thyroidectomy for a wide range of benign and malignant thyroid affliction and brought the tubercle of Zuckerkandl once again into attention. This embryological remnant has been shown to have a constant relationship with the recurrent laryngeal nerve and the superior parathyroid gland and may be used as a landmark for safe dissection. In order to assess if the presence of the tubercle of Zukerkandl has an impact on the most important complications of thyroid surgery, we have prospectively studied 128 patients diagnosed with nodular goiter who underwent total thyroidectomy. Grade 0 or the absence of the tubercle of Zuckerkandl, according to Pellizo et al, was noted in 42 cases (32.8%). During surgery, we identified 38 grade 1 tubercles (29.7%), 31 grade 2 tubercles (24.2%) and 16 grade 3 tubercles (12.5%). Out of 11 bilateral tubercles, 4 were measured as grade 3.Of all 47 patients with grade 2 and 3 tubercles, 18 (38.3%) developed transient postoperative hypocalcemia (p 0.0001, r=0.47) and 10 (21.3%) transient postoperative nerve palsy (p=0.004, r=0.25). All patients fully recovered during follow-up. The tubercle of Zuckerkandl, when present and of significant macroscopic size is associated with increased rates of transient postoperative hypocalcemia and recurrent laryngeal nerve palsy.

Ultrasonographic features of the normal thyroid gland in adult horses / Características ultrassonográficas da glândula tireoide hígida em equinos adultos

Few reports have been published regarding the use of ultrasonography as a method of evaluating the normal thyroid gland in horses. For these reasons, this study aimed at determining reliably of the thyroid measurements from the comparison between the left and right thyroid lobes, as well as assessing the contour, format, echotexture and echogenicity of the healthy thyroid by mode-B ultrasonography. Additionally, the equine thyroid vascularization was quali-quantitatively characterized the by Doppler. The sample size initially was determined by the animal selection with advanced age and without volume increase in the neck proximal region. Finally, eleven horses were selected by laboratory test, search of thyroid neoformations by ultrasonography and cytology thyroid. Next, these animals were submitted to thyroid lobes ultrasonographic evaluation. Excellent reproducibility was observed for all measurements obtained. Among the comparisons made between the quantitative parameters of the left and right lobes, it was observed that there was only difference between their respective lengths. Qualitatively, there was a significant variation between the lobes elliptical format in the longitudinal plane of some glands, which oscillated between a rounded and flattened conformation. Thus, we can conclude that the difference between the lobes format of some thyroids can be explained by the significant difference observed between the length of the left and right lobes. Additionally, it was verified that there was no difference between the Doppler quantitative parameters. Therefore, we may suggest that unilateral analysis of the cranial thyroid artery by spectral Doppler can be used to evaluate equine thyroid diffuse disorders.(AU)

Poucas análises foram publicadas com relação ao uso da ultrassonografia como método de avaliação da glândula tireoide hígida em equinos. Alguns trabalhos incluem a determinação das dimensões e características do parênquima. Por essas razões, este estudo teve como objetivo determinar com segurança as medidas tireoidianas a partir da comparação entre o lobo tireoidiano esquerdo e direito, bem como avaliar os contornos, formato, ecotextura e ecogenicidade das glândulas tireoides hígidas pela ultrassonografia em modo B. Além disso, a vascularização da tireoide equina foi caracterizada quali-quantitativamente pela ferramenta Doppler. O tamanho da amostra inicialmente foi determinado pela seleção dos animais com idade avançada e sem aumento de volume na região proximal do pescoço. Por fim, onze equinos foram selecionados por meio de exame laboratorial, pesquisa de neoformações tireoidianas por ultrassonografia e citologia da tireoide. Em seguida, estes animais foram submetidos à avaliação de lobos tireoidianos por ultrassonografia. Observou-se excelente reprodutibilidade em relação a todas as medidas deste estudo. Foram observadas diferenças qualitativas entre os lobos tireoidianos direito e esquerdo. Assim, podemos concluir que tais diferenças entre o formato dos lobos tireoidianos podem ser explicadas pela diferença significativa e/ou tendência observada no parâmetro comprimento entre os respectivos lobos. Além disso, não foi encontrada diferença significativa entre os valores da artéria tireoidiana cranial esquerda em relação aos obtidos na artéria tireoidiana cranial direita, sugerindo que a análise dos valores espectrais do Doppler de uma das artérias tireoidianas craniais possa ser utilizada como método de avaliação de distúrbios difusos da tireoide equina.(AU)

BRAFV600E mutation: a potential predictor of more than a Sistrunk's procedure in patients with thyroglossal duct cyst carcinoma and a normal thyroid gland.

To assess the utility of mutational markers in determining the most appropriate initial surgery for patients with thyroglossal duct cyst carcinoma (TGDCCa) and a normal thyroid gland. Our sample comprised 15 patients with a diagnosis of TGDCCa and a thyroid gland histologically negative for any malignant involvement, who underwent surgery between the years 1994 and 2017. Clinical records were reviewed and tissue specimens were genetically tested for the presence of the most commonly encountered mutational markers in differentiated thyroid cancer: BRAF, N-RAS, and H-RAS. The primary outcome of interest was the correlation between mutational marker positivity and the T-stage of the primary tumor and its potential implication on therapeutic decision making. All 15 cases were papillary carcinomas with a mean tumor size of 17 mm (2-40 mm). According to the 7th edition of the American Joint Committee on Cancer TNM staging system, these represented: T1 (n = 3), T2 (n = 1), and T3 (n = 11). Cancerous invasion of the pericystic soft tissue and/or hyoid bone was considered T3. BRAFV600E was the only mutational marker identified (7 in 15 cases). All BRAFV600E-positive lesions were T3, necessitating radioactive iodine ablation (RIA) therapy, therefore, total thyroidectomy. The correlation between BRAFV600E positivity and extracystic cancerous extension was statistically significant [1.0 (7/7) vs. 0.5 (4/8); p value = 0.0035]. BRAFV600E positivity seems to be predictive of locally advanced disease mandating RIA therapy. Therefore, it could serve as a preoperative tool that predicts the need for total thyroidectomy, in addition to Sistrunk's procedure.

Can the Zuckerkandl tubercle assist in the location of the inferior laryngeal nerve during thyroidectomies? / O tubérculo de Zuckerkandl pode auxiliar na localização do nervo laríngeo inferior durante tireoidectomias?

OBJECTIVE: to evaluate whether the lateral projection of the thyroid gland, called Zuckerkandl's tubercle (ZT), can assist the surgeon in identifying the inferior laryngeal nerve during conventional open thyroidectomy. METHODS: we conducted a prospective study with 51 patients submitted to thyroidectomy, with a total of 100 resected thyroid lobes, and observed the presence or absence of ZT in sufficient dimensions to be identified without image magnification, its base and height, its location in the gland, and its anatomical relationship with the inferior laryngeal nerve. RESULTS: ZT was present in 68 of the 100 thyroid lobes analyzed (68%). The mean base was 6.7mm on the right side and 7.1mm on the left side, and the average height was 5.7mm on the right side and 6.1mm on the left side. In most of the lobes studied, the tubercle had a minimum height of 5mm (55.9%), with no significant difference between the right and left lobes of the thyroid gland. During surgery, 100% of the identified ZTs were anterior to the inferior laryngeal nerve, just below the nerve entry in the larynx. CONCLUSION: the ZT is a quite frequent entity and large enough to serve as an intraoperative anatomical reference for the inferior laryngeal nerve, next to its entry in the larynx, along with other anatomical references.

OBJETIVO: avaliar se a projeção lateral da glândula tireoide, chamada tubérculo de Zuckerkandl (TZ), pode auxiliar o cirurgião na identificação do nervo laríngeo inferior durante a tireoidectomia convencional aberta. MÉTODOS: estudo prospectivo de 51 pacientes submetidos à tireoidectomia, com um total de 100 lobos tireoidianos ressecados, e observação da presença ou não do TZ em dimensões suficientes para ser identificado sem magnificação de imagem, suas dimensões de base e altura, sua localização na glândula e sua relação anatômica com o nervo laríngeo inferior. RESULTADOS: o TZ estava presente em 68 dos 100 lobos de tireoide analisados (68%). A dimensão média da base foi 6,7mm no lado direito e 7,1mm no lado esquerdo, e a altura média foi 5,7mm no lado direito e 6,1mm no lado esquerdo. Na maioria dos lobos estudados, o tubérculo tinha altura mínima de 5mm (55,9%) sem diferença significativa entre o lobo direito e esquerdo da glândula tireoide. Durante a cirurgia, 100% dos TZ identificados estavam anteriores ao nervo laríngeo inferior, imediatamente abaixo da entrada do nervo na laringe. CONCLUSÃO: o TZ é bastante frequente e em dimensões suficientes para ser usado como referência anatômica na localização intraoperatória do nervo laríngeo inferior, próximo à sua entrada na laringe, junto com as demais referências anatômicas.

Validation of age and height based formulae to predict paediatric airway distances - a prospective observational study.

Background: Preoperative airway evaluation in children is an important part of routine preanesthetic evaluation before surgery. External airway measurements, viz., thyromental, mentohyoid, and sternomental distances, while being growth dependent, could identify pediatric patients with potentially difficult airways. Objectives: This study was conducted to validate the age- and height-based formulae, derived from a previous study conducted in our institute, to predict thyromental distance, sternomental distance, and mentohyoid distance in relation with the height and age of pediatric patients. Design: Prospective cross-sectional single arm observational study. Setting: Tertiary level university teaching hospital from July 2015 to December 2016. Patients: Children (202) in the age group of 3-15 years with no obvious external airway anomaly scheduled for elective surgery under general anesthesia. Outcomes Measured: The thyromental, mentohyoid, and sternomental distances were measured preoperatively. The same parameters were then calculated based on age- and height-related formulae derived in the earlier study. Results: Bland-Altman analysis of the sample patients showed a mean difference (bias) between measured and calculated values ranging from 0.14 to -0.60 (3 - 13%). Overall agreement in terms of bias were found to be more with height-based equation for mentohyoid distance and thyromental distance and age-based equation for sternomental distance. Conclusion: Our study validates the formulae derived in the earlier study to predict thyromental, mentohyoid, and sternomental distances in children with no obvious external airway anomalies. Further studies are needed to extend the applicability of these formulae in obese children and those with craniofacial anomalies coming for general anesthesia and surgery.

Proper handling of the pyramidal lobe in minimal access thyroid procedures.

The thyroid gland is a butterfly-shaped gland located in the lower part of the anterior surface of the neck between the fifth cervical and the first thoracic vertebra. Usually, it consists of two lateral, almost symmetrical lobes, the connective isthmus and the pyramidal lobe. The pyramidal lobe is a conical or cylindrical projection of the gland's parenchyma that extends superiorly to the thyroid cartilage or the hyoid bone. Most often, it originates from the isthmus and it is located to the left of the middle line. It can be absent in up to 50% of the cases. From the time of Theodor Kocher who performed the first classic thyroidectomies, we are now entering the era of minimal access thyroid surgery where new techniques are devised in order to provide a better cosmetic result. The presence of the pyramidal lobe is a classic example of an anatomic variation of the thyroid gland that plays an important role in the completeness of a total thyroidectomy, especially when the procedure is carried out for an autoimmune or malignant disease. The pyramidal lobe can also increase the complexity of minimal access procedures that are nowadays applied for the removal of the thyroid gland. The purpose of this article is to outline the importance of the pyramidal lobe in minimal access thyroid surgery.

Quantitative Assessment of Thyroid Glands in Healthy Children With Shear Wave Elastography.

The local shear wave speed (in meters per second) and Young modulus (in kilopascals) of normal thyroid glands were defined in healthy children to determine reference values.This prospective study assessed 107 pediatric cases (age interval, 3-17 years; mean, 9.37 ± 3.68 years), including 52 boys and 55 girls. The study group included children without thyroid gland disease (autoimmune, infectious, or neoplastic). Data about the sex, age, weight, height, and body mass index (BMI) of the subjects were recorded for all subjects. Elasticity values were measured from 3 different sites in both thyroid lobes and averaged.Median values for elasticity and shear wave velocity measured in bilateral thyroid lobes were 6.38 ± 1.97 kPa (range, 3.00-12.5 kPa) and 1.45 ± 0.21 m/s (range, 1.03-2.04 m/s) on the right and 8.81 ± 3.00 kPa (range, 3.80-22.6 kPa) and 1.69 ± 0.26 m/s (range, 1.13-2.68 m/s) on the left. There was no significant difference between the elasticity values for the right and left thyroid lobes between boys and girls. There was a positive correlation between right thyroid lobe mean elasticity (in kilopascals) and shear wave velocity (in meters per second) values with age, BMI, and right thyroid lobe volume in the whole group. No significant correlation was found between left thyroid lobe mean elasticity (in kilopascals) and shear wave velocity (in meters per second) values with age, BMI, and left thyroid lobe volume in the study population.This study determined mean elasticity and shear wave velocity values for thyroid gland in healthy children. This information can be used as a baseline for the investigation of thyroid diseases.

From thyroid cartilage to thyroid gland.

The ancient Greek physicians skipped the description of thyroid gland probablydue to their difficultly to understand the anatomy and the existence of this organ.Although the ancient physicians had described the disease bronchocele (Greek:Βρογχοκήλη), this disease did not correspond exactly to goitre. The first officialdescription of this gland was made by Andreas Vesalius (1514-1564). Thomas Wharton (1614-1673) in his work Adenographia was the one who coined the term 'Glandulae thyreoidea'.

O tubérculo de Zuckerkandl pode auxiliar na localização do nervo laríngeo inferior durante tireoidectomias? / Can the Zuckerkandl tubercle assist in the location of the inferior laryngeal nerve during thyroidectomies?

RESUMO Objetivo: avaliar se a projeção lateral da glândula tireoide, chamada tubérculo de Zuckerkandl (TZ), pode auxiliar o cirurgião na identificação do nervo laríngeo inferior durante a tireoidectomia convencional aberta. Métodos: estudo prospectivo de 51 pacientes submetidos à tireoidectomia, com um total de 100 lobos tireoidianos ressecados, e observação da presença ou não do TZ em dimensões suficientes para ser identificado sem magnificação de imagem, suas dimensões de base e altura, sua localização na glândula e sua relação anatômica com o nervo laríngeo inferior. Resultados: o TZ estava presente em 68 dos 100 lobos de tireoide analisados (68%). A dimensão média da base foi 6,7mm no lado direito e 7,1mm no lado esquerdo, e a altura média foi 5,7mm no lado direito e 6,1mm no lado esquerdo. Na maioria dos lobos estudados, o tubérculo tinha altura mínima de 5mm (55,9%) sem diferença significativa entre o lobo direito e esquerdo da glândula tireoide. Durante a cirurgia, 100% dos TZ identificados estavam anteriores ao nervo laríngeo inferior, imediatamente abaixo da entrada do nervo na laringe. Conclusão: o TZ é bastante frequente e em dimensões suficientes para ser usado como referência anatômica na localização intraoperatória do nervo laríngeo inferior, próximo à sua entrada na laringe, junto com as demais referências anatômicas.

ABSTRACT Objective: to evaluate whether the lateral projection of the thyroid gland, called Zuckerkandl's tubercle (ZT), can assist the surgeon in identifying the inferior laryngeal nerve during conventional open thyroidectomy. Methods: we conducted a prospective study with 51 patients submitted to thyroidectomy, with a total of 100 resected thyroid lobes, and observed the presence or absence of ZT in sufficient dimensions to be identified without image magnification, its base and height, its location in the gland, and its anatomical relationship with the inferior laryngeal nerve. Results: ZT was present in 68 of the 100 thyroid lobes analyzed (68%). The mean base was 6.7mm on the right side and 7.1mm on the left side, and the average height was 5.7mm on the right side and 6.1mm on the left side. In most of the lobes studied, the tubercle had a minimum height of 5mm (55.9%), with no significant difference between the right and left lobes of the thyroid gland. During surgery, 100% of the identified ZTs were anterior to the inferior laryngeal nerve, just below the nerve entry in the larynx. Conclusion: the ZT is a quite frequent entity and large enough to serve as an intraoperative anatomical reference for the inferior laryngeal nerve, next to its entry in the larynx, along with other anatomical references.

Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis.

PURPOSE: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the external branch of the superior laryngeal nerve (EBSLN). MATERIALS AND METHODS: A thorough systematic search was performed on the major electronic databases PubMed, EMBASE, Cochrane library, and ScienceDirect to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcomes were the EBSLN identification rate (total number of EBSLN identified divided by the total number of dissected hemilarynges) and the prevalence of various EBSLN types. RESULTS: A total of 56 studies (n = 13,444 hemilarynges) were included. The overall pooled EBSLN identification rate was 89.24% (95% CI 85.49-92.49). This rate was higher for cadaveric (95.00%; 95% CI 89.73-99.35) compared to that reported in intraoperative studies (86.99%; 95% CI 82.37-91.01). Significantly higher identification rates were reported for studies in which intraoperative nerve monitoring was used (95.90%; 95% CI 94.30-97.25) compared to those which only relied on direct visual identification of the EBSLN (76.56%; 95% CI 69.34-83.08). Overall, Cernea type IIa (nerves crossing the superior thyroid artery less than 1 cm above the upper edge of the superior thyroid pole) and Friedman type 1 (nerves running their entire course superficial to the inferior pharyngeal constrictor) were the most prevalent (41.84%; 95% CI 33.28-48.08 and 50%; 95% CI 29.90-65.62, respectively). The combined prevalence of Cernea IIa and IIb (nerves crossing the superior thyroid artery below the upper edge of the superior thyroid pole) was higher in intraoperative studies compared to that in cadaveric studies (64.3% vs 49.4%). The EBSLN coursed medial to the superior thyroid artery in 70.98% (95% CI 55.14-84.68) of all cases. CONCLUSION: The use of intraoperative nerve monitoring improves EBSLN identification rates. In light of the highly variable anatomical patterns displayed by the EBSLN, thorough pre-operative knowledge of its anatomy can be crucial in minimizing incidences of its iatrogenic injury.