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)

Anatomía quirúrgica de la vena tiroidea media: prevalencia en 100 tiroidectomías totales consecutivas / Surgical anatomy of the median thyroid vein: prevalence in 100 consecutive total thyroidectomies

El estudio de las venas tiroideas no ha recibido una investigación tan exhaustiva como lo tuvieron las arterias tiroideas y los nervios laríngeos en relación a la cirugía tiroidea.De los tres pedículos venosos de la glándula tiroides, el medio, de lejos es el menos estudiado. La vena tiroidea media es inconstante y es el primer elemento vascular de la glándula tiroides que debe ser seccionado antes de luxar el lóbulo hacia medial para evaluar sus relaciones posteriores. Su lesión puede provocar sangrado intraoperatorio dificultando secundariamente la identificación del nervio laríngeo inferior y las glándulas paratiroides, próximas a la misma. Se realizó un estudio descriptivo de corte transversal evaluando la pesencia, número, simetría y asociación de la vena tiroidea media con variables tales como edad y sexo del paciente, así como la hiperfuncionalidad de la glándula tiroides y la presencia del tubérculo de Zuckerkandl en 100 tiroidectomías totales llevadas a cabo en el Instituto Nacional del Cáncer y en el Servicio de Otorrinolaringología del Hospital Central del Instituto de Previsión Social del Paraguay. La prevalencia global de vena tiroidea media fue del 74 %. En el lóbulo derecho, la vena se presentó en el 60 %, mientras que en el lóbulo izquierdo en el 53 %. En el 38 % se encontró la vena en ambos lóbulos. En 4 pacientes se localizaron venas tiroideas medias dobles, en una de ellas fue bilateral. El mayor porcentaje de las venas tiroideas medias se originó en el tercio medio del lóbulo, el 72 % en el lado derecho y el 70% en el izquierdo. No se encontró asociación entre la presencia de la vena tiroidea media y la edad, sexo, estado de hiperfunción glandular, así como tampoco con la presencia del tubérculo de Zuckerkandl.

The study of the thyroid veins has not received an investigation as extensive as the thyroid arteries and laryngeal nerves did in relation to thyroid surgery. Of the three veins pedicles of the gland the middle is far the least studied. This vein is inconstant and is the first vascular element of the gland that must be sectioned before the medial lobe is dislocated to evaluate ist posterior relationships. His injury can cause intraoperative bleeding, making it difficult to identify the inferior laryngeal nerve and the parathyroid glands, proximal to it. A descriptive crossseccional study was carried aot evaluating the presence, number, symmetricity and association of the middle thyroid vein with variables such as age and sex of the patient, as well as the hyperfunctionality of the gland and the presence of the Zuckerkandl tubercle in 100 total thyroidectomies undergoing at the National Cancer Institute and the ENT Service of the Social Security Institute´s Central Hospital. The overall prevalence of the middle thyroid vein was 74%. In the right lobe the vein appeared in 60% while in the left lobe in 53 %. Double middle thyroid vein was found in 4 patients, in one of them it was bilateral. The highest percentage of the middle thyroid veins originated in the middle third of the lobe, 72 % on the right and 70% on the left side. No association was found between the presence of the vain and age and sex, the state of glandular hyperfunstion, as well as the presence of Zuckerkandl tubercle.

Anatomía topográfica del nervio laríngeo superior: importancia quirúrgica en las tiroidectomías / Topographic anatomy of the upper laryngeal nerve: surgical importance in thyroidectomies

En las cirugías sobre la glándula tiroides se ha prestado mucha atención al manejo del nervio laríngeo inferior y de las glándulas paratiroides, no así del ramo lateral del nervio laríngeo superior, el cual es satélite del pedículo vascular superior de la glándula tiroides. El manejo del polo superior de la glándula tiroides requiere de un conocimiento acabado de su anatomía topográfica del área y está determinada por sus relaciones más importantes, dadas por el citado nervio y la arteria tiroidea superior principalmente. En este trabajo se pretende estudiar estas relaciones en base a la disección meticulosa del triángulo laringo-esternotiroideo ("Triángulo de Joll") de 25 cadáveres adultos formolizados. Como hallazgo relevante se informa que los "nervios en riesgo", según la clasificación de Cernea, que se basa en una distancia menor a un centímetro en el entrecruzamiento del nervio con la arteria tiroidea superior con respecto al polo superior de la glándula tiroides, es del 52 % para el lado derecho y 44 % para el lado izquierdo del cuello. El origen bajo de la arteria a nivel de la bifurcación carotídea se presenta asociada a un mayor número de "nervios en riesgo" en el lado izquierdo. Según el punto de penetración del ramo lateral del nervio laríngeo superior en el músculo constrictor inferior de la faringe se establece la clasificación de Friedman, muy útil sobre todo en cirugías ayudadas por la neuroestimulación. En esta clasifiacción los "nervios en riesgo" son aquellos que transcurrren superficial al músculo, mientras que los "nervios protegidos" serían aquellos que perforan el músculo en su porción superior. En este trabajo los "nervios en riesgo" se presentaron del lado izquierdo en el 56 % de los casos y del derecho en el 60 %, mientras que los "nervios protegidos" en el 24 % y 16 %, respectivamente.

In surgeries on the thyroid gland, much attention has been given to the management of the inferior laryngeal nerve and parathyroid glands, but not the external branch of the given by the aforementioned nerve and the superior thyroid artery. This paper intends to study these relationships based on the meticulous dissection of the larynx-sternothyroid triangle ("Joll triangle") of 25 formolized adult corpses. As a relevant finding, it is reported that the " nerves at risk" according to the Cernea classification, which is based on the distance less than one centimeter at the intersection of the nerve with the superior thyroid artery with respect to the upper pole of the gland, is 52 % for the right side and 44 % for the left side of the neck. The low origin of the artery at the level of the carotid bifurcation is associated with a greater number of "nerves at risk" on the left side. According to the penetration point of the external branch of the superior laryngeal nerve in the inferior pharyngeal constrictor muscle, the Friedman classification is established, very useful especially in surgeries aided by neurostimulation. In this classification the "nerves at risk" are those that run superficially to the muscle, while the protected nerves would be those that pierce the muscle in its upper part. In tis work, the "nerves at risk" presented on the left side in 56 % of the cases and the right side in 60 %, while those "protected" in 24 % and 16 % respectively.

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.

Comparison between peak systolic velocity of the inferior thyroid artery and technetium-99m pertechnetate thyroid uptake in differentiating Graves' disease from thyroiditis

ABSTRACT Objectives The differentiation between the various etiologies of thyrotoxicosis, including those with hyperthyroidism (especially Graves' disease [GD], the most common cause of hyperthyroidism) and without hyperthyroidism (like thyroiditis), is an important step in planning specific therapy. Technetium-99m (99mTc) pertechnetate thyroid scanning is the gold standard in differentiating GD from thyroiditis. However, this technique has limited availability, is contraindicated in pregnancy and lactation, and is not helpful in cases with history of recent exposure to excess iodine. The aim of this study was to identify the diagnostic value of the peak systolic velocity of the inferior thyroid artery (PSV-ITA) assessed by color-flow Doppler ultrasound (CFDU) and compare the sensitivity and specificity of this method versus 99mTc pertechnetate thyroid uptake. Subjects and methods We prospectively analyzed 65 patients (46 with GD and 19 with thyroiditis). All patients were evaluated with clinical history and physical examination and underwent 99mTc pertechnetate scanning and measurement of TRAb levels and PSV-ITA values by CFDU. The diagnosis was based on findings from signs and symptoms, physical examination, and 99mTc pertechnetate uptake. Results Patients with GD had significantly higher mean PSV-ITA values than those with thyroiditis. At a mean PSV-ITA cutoff value of 30 cm/sec, PSV-ITA discriminated GD from thyroiditis with a sensitivity of 91% and specificity of 89%. Conclusion Measurement of PSV-ITA by CFDU is a good diagnostic approach to discriminate between GD and thyroiditis, with sensitivity and specificity values comparable to those of 99mTc pertechnetate thyroid uptake.

Is there an association between thyroid function abnormalities and breast cancer?

ABSTRACT Objective The aim of this study was to evaluate the association between thyroid function abnormalities and breast cancer and, in particular, the prognostic markers of breast cancer.. Subjects and methods Baseline levels of thyrotropin, free triiodothyronine, free thyroxine and thyroid autoantibodies were measured in 97 women with primary breast cancer, 27 women with benign breast disease, and 4 women with atypical ductal hyperplasia. Their baseline levels were compared with those in 48 healthy women with a normal mammography in the last 2 years. Results There were no significant associations between history of thyroid disease and breast cancer (p = 0.33). The mean baseline levels of triiodothyronine and thyrotropin did not differ significantly between the compared groups. The mean baseline levels of free thyroxine were found to be significantly higher in the breast cancer group, even after adjusting for thyroid replacement therapy. The presence of thyroid antibodies did not differ significantly between the compared groups. In a subgroup analysis, breast cancer cases with thyroid disease and particularly hypothyroidism had a significantly lower incidence of lymph node metastases compared with breast cancer cases without thyroid disease. Conclusions Our data confirmed the proliferative effect of thyroid hormones on breast cells, which had previously been shown in vitro. Additionally, thyroid disease and particularly hypothyroid function appeared to be associated with a lower incidence of lymph node metastases. Further studies to determine the prognostic role of thyroid hormones in breast cancer are warranted.

Irrigación de la glándula tiroides en una muestra de población colombiana / Thyroid gland irrigation in a sample of Colombian population

La glándula tiroides es un sitio frecuente de patologías, que requiere abordaje quirúrgico. Dichas técnicas, aunque bien establecidas, generan ocasionalmente complicaciones que, por lo general, se presentan por inexperiencia del cirujano o por variaciones anatómicas no previstas. El conocimiento y el estudio de estas variaciones son importantes, con el fin de limitar las complicaciones asociadas a procedimientos quirúrgicos de la glándula tiroides, disminuir la morbimortalidad asociada y mejorar la interpretación de las técnicas de imágenes diagnósticas. Se practicó un estudio descriptivo, con 67 bloques cervicocardiopulmonares y digestivos, en cadáveres de 64 hombres y 3 mujeres. Se realizó disección de la región cervical, a nivel de la glándula tiroides, identificando el origen, el trayecto y las relaciones de las arterias que irrigan a la glándula tiroides y, de igual manera, se buscó la presencia o no de la arteria tiroidea media (IMA). El total de 67 bloques estudiados evidenció que todos presentaban ambas arterias tiroideas bilateralmente. En todos los bloques analizados, la arteria tiroidea superior, se originó de la arteria carótida externa y siguió el recorrido clásico; la arteria tiroidea inferior, se inició en los 67 bloques del tronco tirocervical y, en 64 pacientes, el nervio laríngeo recurrente, se ubicó posterior a la arteria; solamente en 3 casos, se halló anteriormente. Se confirmó presencia de arteria tiroidea IMA en 4 pacientes, que corresponde al 6% de los bloques. Los hallazgos de este estudio mantienen una gran correlación con la descripción clásica de la irrigación de la glándula tiroides en poblaciones occidentales. Con un origen y trayecto de ambas arterias tiroideas, que guardan una adecuada correlación con lo descrito previamente. La presencia de arteria tiroidea IMA fue inferior a lo reportado en la mayoría de las series de estudios.

The thyroid gland is a frequent site of pathology that requires surgical approach. Such techniques, although well-established is occasionally complicated, which usually occurs because of the inexperienced surgeon or unintended anatomical variations. The knowledge and study of these variations are important in order to limit the complications associated with surgical procedures of the thyroid gland, reduce associated morbidity and mortality and improve the performance of diagnostic imaging techniques. A descriptive study was performed with 67 digestive and cervico cardiopulmonary blocks, in cadavers 64 men and 3 women. Dissection of the cervical region was performed at the level of the thyroid gland, identifying the origin, course and relations of the arteries supplying the thyroid gland and, likewise, sought the presence or absence of the middle thyroid artery (IMA). The total of 67 blocks studied showed that all had both thyroid arteries bilaterally. In all blocks analyzed, the superior thyroid artery originated from the external carotid artery and followed the classic route; the inferior thyroid artery, started in the 67 blocks thyrocervical trunk and in 64 patients, the recurrent laryngeal nerve was located posterior to the artery; only in 3 cases, it was found above. IMA presence of thyroid artery in 4 patients, corresponding to 6% of the blocks was confirmed. The findings of this study remain highly correlated with the classical description of the irrigation of the thyroid gland in Western populations, in an origin and course of both thyroid arteries that have a good correlation with those previously described. The presence of thyroid artery IMA was lower than that reported in most series of studies.

Is the measurement of inferior thyroid artery blood flow velocity by color-flow Doppler ultrasonography useful for differential diagnosis between gestational transient thyrotoxicosis and Graves' disease? A prospective study

OBJECTIVE: To determine the role of peak systolic velocity, end-diastolic velocity and resistance indices of both the right and left inferior thyroid arteries measured by color-flow Doppler ultrasonography for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy. METHODS: The right and left inferior thyroid artery-peak systolic velocity, end-diastolic velocity and resistance indices of 96 patients with thyrotoxicosis (41 with gestational transient thyrotoxicosis, 31 age-matched pregnant patients with Graves' disease and 24 age- and sex-matched non-pregnant patients with Graves' disease) and 25 ageand sex-matched healthy euthyroid subjects were assessed with color-flow Doppler ultrasonography. RESULTS: The right and left inferior thyroid artery-peak systolic and end-diastolic velocities in patients with gestational transient thyrotoxicosis were found to be significantly lower than those of pregnant patients with Graves' disease and higher than those of healthy euthyroid subjects. However, the right and left inferior thyroid artery peak systolic and end-diastolic velocities in pregnant patients with Graves' disease were significantly lower than those of non-pregnant patients with Graves' disease. The right and left inferior thyroid artery peak systolic and end-diastolic velocities were positively correlated with TSH-receptor antibody levels. We found an overlap between the inferior thyroid artery-blood flow velocities in a considerable number of patients with gestational transient thyrotoxicosis and pregnant patients with Graves' disease. CONCLUSIONS: This study suggests that the measurement of inferior thyroid artery-blood flow velocities with colorflow Doppler ultrasonography does not have sufficient sensitivity and specificity to be recommended as an initial diagnostic test for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.

[ rare case report of the Thyroidea Ima and the thymic arteries common trunk, arising from the brachiocephalic artery]

The Thyroidea Ima artery [The artery of Neubauer], was recognized and described by Neubauer in 1786. This artery which was described in the all anatomical textbooks may arise from the arch of aorta, brachiocephalic trunk or other arteries in the upper mediastina. It is considered as a compensatory artery when the other thyroidal vessels showed deficiencies. This artery showed greatly variation in size and gave some anastomotic branches to the thymic artery. The thymic artery arised from the anterior mediastinal branch of the internal thoracic artery but, may also arise from the brachiocephalic trunk, arch of aorta, common carotid or the main trunk of the internal thoracic artery. Its origin from the thyroidea ima is rare. This rare case was seen in a 65 years old male cadaver, the common trunk of the thyroida ima and the thymic arteries originated from the brachiocephalic artery. After a short course it divided into two branches: an ascending [thyroida ima] and descending [thymic] branches. The thyroidea ima artery turned to left and upward to the lower border of the isthmus of thyroid gland. At this point it sent a branch to the lower part of the left lobe of the thyroid which penetrated it deeply and ended in the left inferior parathyroid gland. The main branch continued its course upward to the upper border of the thyroidal isthmus and divided into right and left branches. Each of these branches, after sending a great anastomotic branch to the superior thyroidal artery of their own side, terminated as several small branches in the upper part of the right and left lobes of the thyroid gland. The thymic artery continued its course downward for about three centimeters and ended as two branches in the right and left lobes of thymus. The thyroid gland of this cadaver was larger than the normal ones and the thymus was also clearly noticeable with right and left bobs. According to the embryonic origin and the developmental processes of the inferior parathyroid glands and the Thymus from the neighboring pharyngeal pouches, their blood supply from a common trunk will be acceptable especially when these two glands show some degree of enlargement as shown in this case. In the cases of thyroidectomies, when a surgeon is going to resect an enlarged thyroid gland, the presence of thyroidea ima artery and its branches to the lower part of lobes of thyroid gland would be a useful guidance to identify the inferior parathyroid glands an save them for the prevention of the next hypocalcemia

Anatomía quirúrgica del drenaje venoso en la región del triángulo carotídeo / Surgical anatomy of jugular vein tributaries

Background: The main tributaries of the internal jugular vein join at cervical level through the venous thyrolinguofacial trunk. This trunk is classically described as formed by the union of the facial, superior thyroid and lingual veins. Aim: To evaluate variations in the formation of the thyrolinguofacial trunk in human cadavers. Material and Methods: Thirty hemi-necks were dissected in human cadavers of nine men and six women, with ages ranging between 29 and 50 years, and analyzed by direct observation. Results: In 16 hemi-necks (53.3 percent), the trunk was thyrolinguofacial; in seven (23.3 percent), it was linguofacial; in six (20 percent), it was thyrolingual and in one case (3.3 percent) it was thyrolinguo pharyngofacial. No thyrofacial trunk formation was found. There was a correlation between the diameter of the internal jugular vein and of the venous trunk formed by these veins. Conclusions: There are morphological changes in the formation patterns of facial, lingual and superior thyroid veins. This information is useful for surgical oncology, plastic surgery, head and neck surgery and radiology.

Los principales afluentes de la vena yugular interna se incorporan a nivel cervical por medio del tronco venoso tirolinguofacial. Clásicamente se ha descrito su formación por la unión de la vena facial, lingual y tiroidea superior. El objetivo de este estudio fue determinar las variaciones en la presentación del tronco tirolinguofacial en cadáveres humanos de la región del Maule, Chile. Se disecaron 30 hemicuellos pertenecientes a 15 cadáveres humanos de ambos sexos, con un rango de edad entre 29 y 50 años, y se analizaron mediante observación directa. Se observó la formación de tronco venoso en la totalidad de los casos, siendo 53,3 por ciento correspondiente al tronco de tipo tirolinguofacial, 23,3 por ciento linguofacial, 20 por ciento tirolingual y sólo un 3,3 por ciento el tronco tirolinguofaringofacial. No se encontró la formación del tronco venoso de tipo tirofacial. Además se encontró una correlación significativa entre el diámetro de la vena yugular interna y el tronco venoso conformado por estas venas. Por lo tanto, existen variaciones morfológicas en los patrones de conformación de las venas facial, lingual y tiroidea superior, siendo estos datos de importancia para áreas de cirugía oncológica, cirugía plástica, cirugía de cabeza y cuello y radiología.

Utility of colour Doppler Sonography in patients with graves' disease / Utilidad de la Sonografía Doppler en color en pacientes con la enfermedad de graves

OBJECTIVE: Assessment of thyroid blood flow gives valuable information about underlying functional status. Colour Flow Doppler Sonography (CFDS) is a powerful tool which displays tissue blood flow and vascularity. Colour Flow Doppler Sonography of the thyroid gland in different subsets of patients with Graves' disease was studied to define its role in initial diagnosis and management. METHODS: Eighty consecutive patients with Graves' disease (both treated and untreated) presented to hospital between August 2007 and February 2008. All patients were evaluated with CFDS of the thyroid for size, vascularity and peak systolic velocity (PSV) of the Inferior Thyroid Artery (ITA). Pertechnate scan and thyroidal autoantibody levels were done in selected cases. The patients were divided into Untreated Graves' disease (n = 31), Graves' disease on treatment but hyperthyroid (n = 26) and euthyroid Graves' disease on therapy (n = 23). Mann-Whitney U-test was used for statistical analysis and a p-value of less than 0.05 was considered significant. RESULTS: Thyroid blood flow, as assessed by PSV of ITA, was significantly higher in untreated Graves' disease than in Graves disease on treatment but hyperthyroid and euthyroid Graves respectively (61.5 ± 19.5 versus 42.9 ± 24.7 versus 32.2 ± 12.9 cm/s, p < 0.05). Parenchymal vascularity of the thyroid gland was higher in hyperthyroid patients than in euthyroid patients irrespective of therapy. In both groups on therapy, the dose of carbimazole correlated with the vascularity of the gland (r = 0.492 versus 0.564, p < 0.05). Colour Flow Doppler Sonography parameters correlated significantly with pertechnate scan results giving comparable sensitivity and specificity. CONCLUSION: Assessment of thyroid blood flow by CFDS is an effective marker in the initial diagnosis of Graves' disease. Vascularity of the gland can predict long term disease course while on medical therapy.

OBJETIVO: La evaluación del flujo sanguíneo tiroideo ofrece una valiosa información acerca del estatus funcional subyacente. La sonografía del flujo con Doppler a color (CFDS) es un poderoso instrumento que muestra el flujo del tejido sanguíneo y la vascularidad. La sonografía con Doppler a color, de la glándula tiroides en diferentes subconjuntos de pacientes con la enfermedad de Graves, fue estudiada para definir su papel en el diagnóstico inicial y el tratamiento. MÉTODOS: Ochenta pacientes consecutivos con la enfermedad de Graves (con y sin tratamiento) acudieron al hospital entre agosto de 2007 y febrero de 2008. Mediante CFDS, a todos los pacientes les fueron evaluados el tamaño del tiroides, la vascularidad y la velocidad del pico sistólico (PSV) de la arteria tiroidea inferior (ATI). En casos seleccionados, se realizaron gammagrafías con pertecnetato y estudios de los niveles de anticuerpos tiroideos. Los pacientes fueron clasificados tomando como criterios: la enfermedad de Graves sin tratamiento (n = 31), la enfermedad de Graves con tratamiento pero hipertiroideos (n = 26), y la enfermedad de Graves eutiroidea bajo terapia (n = 23). La prueba U de Mann-Whitney fue utilizada para el análisis estadístico, y un valor p menor de 0.05 fue considerado significativo. RESULTADOS: El flujo sanguíneo tiroideo tal cual fue evaluado mediante PSV de ATI, fue significativamente más alto en la enfermedad de Graves sin tratamiento que en otros grupos (61.5 ± 19.5 versus 42.9 ± 24.7 versus 32.2 ± 12.9 cm/s, p < 0.05). La vascularidad parenquimal de la glándula tiroides fue mayor en los pacientes hipertiroideos, independientemente de la terapia. En los dos grupos bajo terapia, las dosis de carbimazol estaban en correlación con la vascularidad de la glándula (r = 0.492 versus 0.564, p < 0.05). Los parámetros de la sonografía del flujo con Doppler a color guardaban una correlación significativa con los resultados de la gammagrafía de pertecnetato, arrojando sensibilidad y especificidad comparables. CONCLUSIÓN: La evaluación del flujo sanguíneo del tiroides mediante CFDS es un marcador efectivo en el diagnóstico inicial de la enfermedad de Graves. La vascularidad de la glándula puede predecir el curso de la enfermedad a largo plazo, bajo terapia médica.

Relações do ramo externo do nervo laríngeo superior com a artéria tireóidea superior: estudo em 101 nervos / Relation between the external branch of the superior laryngeal nerve and the superior thyroid artery: a study in 101 nerves

OBJETIVO: Construir um protocolo das relações anatômicas topográficas do ramo externo do nervo laríngeo superior (NLSE) com a artéria tireóidea superior, para minimizar as falhas das propostas descritas na literatura. MÉTODOS: Foram dissecadas bilateralmente as regiões cervicais de 57 cadáveres frescos, no Instituto Médico-Legal do Estado do Amazonas, com identificação fotográfica dos NLSE e respectivas relações com a artéria tireóidea superior. A partir dos dados obtidos elaborou-se classificação: Tipo1: NLSE não identificado; Tipo 2: NLSE cruza a artéria tireóidea superior a distância maior de 1,5cm do limite cranial do lobo da glândula tireóide; Tipo 3: NLSE cruza a artéria entre 1cm e 1,5cm do limite cranial do lobo da glândula tireóide; Tipo 4: NLSE cruza a artéria a menos de 1cm do limite cranial do lobo da glândula; Tipo 5: NLSE cruza, látero-medialmente, abaixo do limite cranial do lobo tireóideo. Como suplemento classificatório, os tipos 2, 3 e 4 receberam subclassificação: A - quando se encontrava parcial ou totalmente envolto no tecido conjuntivo superficial peri-muscular ou intra-muscular, no constritor inferior da faringe, em mais da metade de seu percurso, após cruzar a artéria tireóide superior; B - quando se encontrava fora destes tecidos. RESULTADOS: Tipo 1, 11,88 por cento; Tipo 2, 13,86 por cento; Tipo 3, 34,65 por cento; Tipo 4, 38,61 por cento e Tipo 5, 0,99 por cento. CONCLUSÃO: Os NLSE mais próximos ao limite cranial (Tipos 3 e 4) percorriam, em sua maioria, o tecido frouxo peri-muscular ou intramuscular, no pólo superior da tireóide, o que neste estudo, desobrigam identificação sistemática do nervo nas tireoidectomias (p=0,075).

OBJECTIVE: This paper aims to propose a protocol with the topographical relations of the ESLN and the superior thyroid artery in order to minimize the number of flaws in the proposals found in the literature. METHODS: the cervical regions of 57 human cadavers from the Forensic Medicine Institute were dissected bilaterally, with photographic identification of the ESLNs and their relation to the superior thyroid artery. These data were used to propose the following classification: Type 1: unidentified ESLN; Type 2: the ESLN crosses the superior thyroid artery 1.5 cm above the upper pole of the thyroid gland; Type 3: the ESLN crosses the superior thyroid artery between 1 and 1.5cm above the upper pole of the thyroid gland; Type 4: the ESLN crosses the superior thyroid artery less than 1cm above the upper pole of the thyroid gland; Type 5: the ESLN crosses lateral-medially below the upper pole of the thyroid gland. As a supplement, types 2, 3 and 4 received the subclassification: A - the ESLN was partially or totally enclosed in the perimuscular or intramuscular areolar connective tissue, in the inferior pharyngeal constrictor muscle, in more than half of its path after crossing the superior thyroid artery; B - the ESLN was not enclosed in either of these tissues. RESULTS: Type 1, 11.88 percent; Type 2, 13.86 percent; Type 3, 34.65 percent; Type 4, 38.61 percent; Type 5, 0.99 percent. CONCLUSION: the majority of the ESLN nearest to the upper pole of the gland (types 3 and 4) followed the perimuscular or intramuscular superficial connective tissue in the upper pole of the thyroid gland, which, in this study, disobliges the systematic identification of the nerve in thyroidectomies (p=0.075).

Carotid triangle approach to control superior thyrovascular pedicle a novel technique to avoid strap muscles cutting during thyroidectomy

Strap muscles division during thyroidectomy is a controversial issue. The role of strap muscles in voice and swallowing functions and the postoperative morbid sequelae after strap muscles cutting are all debatable. So we have been enthused to develop a surgical approach that enables us to avoid such an unnecessary invasiveness, an idea that seems to be in harmony with both surgical orthodoxy and modern surgical trends. To give a precise detailed stepwise description of such proposed procedural surgical approach and its anatomical basis with the assessment of its feasibility and safety. 30 cases 35:60 years, F:M [2:1] presenting to authors hospitals for thyroidectomy from April through October 2009; were selected for lateral approach where we approach the superior thyrovascular pedicle and the middle thyroid vein through the carotid triangle. Eligibility criteria were: Huge goitres, strong taut strap muscles in males, retr opharyngyal, retro-oesophageal or large Zuckerkandl tuberculum and vascular goitres with marked adhesions. Patients with small goitres, recurrent goitres, previous neck irradiation, and malignant goitres were excluded. Intraoperative and postoperative data were gathered for procedural assessment There were no intraoperative morbidity, and the procedure succeeded in all of the study cases with no conversion to strap muscles cutting. RLN was identified in 28 pts and EBSLN in 10. Parahtyroid glands were identified in 27pts. The mean intraoperative blood loss was 70 cc, the mean operative time was 90 minutes, postoperative pain was well tolerated, mean amount of postoperative drainage was 78 cc with a mean duration of 2 days and a mean hospital stay of 3 days. there were no RLN or sympathetic nerve injury but only one developed transient EBSLN injury and 2 developed transient hypoparathyroidism. carotid triangle approach to control the superior thyrovascular pedicle enables us to avoid aggressive surgical handling of strap muscles by cutting or even excessive exhausting muscle retraction and gland manipulation with their possible morbid sequlae. It is an expeditious approach that facilitates surgery without compromising safety, we believe it to be a reasonably straightforward technique to learn and to be an appropriate addition to the armamentarium of endocrine surgeon whenever indicated

Effect of bilateral Truncal ligation of the inferior thyroid artery on serum calcium levels after subtotal thyroidectomy

Hypocalcaemia is a well recognized complication of thyroid surgery. We have compared the prevalence of hypocalcaemia in our patients following ligation and non-ligation of the inferior thyroid artery after thyroid surgery. A prospective study was done from January 2004 to December 2007, at Assiut University Hospital. All patients [110 patients] undergoing subtotal thyroidectomy were placed in two groups at random. Group I [55 patients] had inferior thyroid arteries ligated whereas in Group II [55 patients], inferior thyroid arteries were not ligated Serum calcium levels were measured before and after surgery. 110 patients were operated [90 females and 20 males], 55 patients in Group I and similar number in Group II Transient hypocalcaemia was observed in 2 [3.63%] patients in Group I and in one [1.81%] patient in Group II. Permanent hypocalcaemia was observed in one [1.81%] patient in Group I and no permanent hypocalcaemia recorded in Group II. Results were statistically insignificant. There is no significant difference in post-operative hypocalcaemia whether or not the inferior thyroid arteries were ligated

To ligate or not the inferior thyroid artery to avoid hypocalcaemia after thyroid surgery

Hypocalcaemia is a well recognized complication of thyroid surgery. We have compared the prevalence of hypocalcaemia in our patients following ligation and non-ligation of the inferior thyroid artery [ITA] during thyroid surgery. A prospective observational study was done from January 2000 to December 2004, at Fauji Foundation Hospital, Rawalpindi. All patients undergoing subtotal or total thyroidectomy were placed in two groups at random. Group I had ITA ligated whereas in Group II, ITA was not ligated. 310 patients were operated, majority of them being female [97.10%]. Transient hypocalcaemia was observed in 4.29% patients in Group I and 3.4% patients in Group II. Permanent hypocalcaemia was observed in 1.84% and 1.36% patients in Group I and Group II, respectively. Results were statistically insignificant [p value > 0.5%]. There is no significant difference in post-operative hypocalcaemia whether or not the ITA is ligated

Morphological study of recurrent laryngeal nerve in relation to thyroid gland.

The study was done to see the relationship of recurrent laryngeal nerves with corresponding inferior thyroid artery with the aim to increase the knowledge regarding variational anatomy in our population. Sixty samples were collected as block dissection of thyroid gland along with the surrounding structures containing the supplying vessels and adjacent nerves from 48 male and 12 female cadavers of different age groups and fixed in 10% formol-saline solution. Fine dissections were carried out to study the toporgaphic relationship of recurrent laryngeal nerves with corresponding inferior thyroid artery. The findings were compared between different age groups and also with the findings of western researchers. In this study, in majority of the cases the recurrent laryngeal nerves were found in their usual location that is posterior to the terminal branches of inferior thyroid artery on the left side and anterior to that artery on the right side. It was important to note that, on both sides recurrent laryngeal nerves were also frequently found to pass in between the terminal branches of inferior thyroid artery.

Ultrasonografía de tiroides / Ultrasound of thyroid

El estudio ultrasonográfico del tiroides aporta importante información respecto asus dimenciones, volumen, irrigación, patología nodular benigna y maligna, incidentalomas y procesos inflamatorios glandulares. Todo esto muchas veces es complementado con Punción Aspirativa con Aguja Fina (PAAF) bajo visión ecográfica, que constituye un método de excelente rendimiento (sensibilidad cercana al 90 por ciento) y de bajo costo, que permite, en un importante porcentaje de los casos, el diganóstico definitivo en la patología nodular

Relationship between the recurrent laryngeal nerve and the inferior thyroid artery: a study in corpses

The anatomical relationship between the recurrent laryngeal nerve (RLN) and the inferior thyroid artery (ITA) was studied in 76 embalmed corpses, 8 females and 68 males. In both sexes, the RLN lay more frequently between branches of the ITA.; it was found in this position in 47.3 percent of male corpses and 42.8 percent of female ones. On the right, RLN was found between branches of the ITA in 49.3 percent of the cases, anterior to it in 38.04 percent, and posterior in 11.26 percent. On the left, the RLN lay between branches of the ITA in 44.45 percent, posterior to the ITA in 37.05 percent, and anterior to it in 18.05 percent of the cases. In 62.68 percent of the cases, the relationship found on one side did not occur again on the opposite side. There was a significant difference (p<0.05) in the distribution of the 3 types of relationships between the RLN and the ITA, on the right and on the left. Racial variations could contribute to an explanation of the differences observed by authors of different countries in the relationship between the RLN and the ITA

The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy

We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA) on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc. RESULTS: A significant incidence of postoperative hypocalcemia occurred: 17 percent in group A and 13 percent in B on the 4th postoperative day. Six months later, the incidence was 5 percent in Group A and 0 percent in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations. CONCLUSION: The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy