Recurrent thyroid carcinoma in a dog - diagnosis by 18F-fluorodeoxyglucose positron emission tomography

Background: Thyroid tumor is a common endocrine tumor that accounts for up to 3.8% of all tumors in dogs. Most of them are malignant and usually nonfunctional in dogs. 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is an imaging modality that detects intracellular accumulation of radioactive deoxyglucose administered in the body and is used in combination with computed tomography to provide functional information with exact anatomical localization. It is used in human medicine to detect residual or recurrent head and neck neoplasm after treatments, such as surgical resection. This report describes the first case of diagnosing recurrent thyroid carcinoma (TC) through FDG-PET in a dog. Case: A 9-year-old castrated male Maltese dog presented with a palpable mobile mass in the right ventral cervical region. Radiography and ultrasonography (US) showed a radiopaque mass adjacent to the trachea, and the right thyroid gland was enlarged on computed tomography. The surgically excised mass was encapsulated and measured to be 2.3 × 1.0 × 3.4 cm (width x length x height) in size. Histopathologically, the mass was diagnosed as differentiated follicular TC, and gross and vascular invasions were observed. To prevent recurrence, postoperative carboplatin chemotherapy was performed for 5 months. Two months after completion of chemotherapy, a nodule of approximately 7 mm in diameter was detected in the thyroidectomy bed by US. FDG-PET scanning was performed as an effective means of evaluating the malignancy, local recurrence, and metastasis of differentiated follicular TC. The nodule had the dimensions of 2.8 × 5.9 × 8.6 mm, a maximum standardized uptake value (SUV) of 8.49, and a mean SUV of 5.6. The results of FDG-PET suggested the recurrence of TC; therefore, the second chemotherapy protocol using toceranib was applied for 16 months. After initiation of the 2nd chemotherapy, follow-up examinations were conducted approximately every 4 months. On the 134th day, although the nodule was not palpated, its size was observed to have increased to 5.0 × 3.8 × 13.6 mm on cervical US on the 232nd day, showing heterogeneous and hypoechoic parenchyma. On the 405th day, the tumor was enlarged to a size of 13.4 × 12.9 × 22 mm and identified as a lobular, amorphous shape, and its heterogeneity was increased. Moreover, 2 pulmonary nodules with well-defined margins were found on radiography in the left caudal lung lobe (9 × 10 mm and 12 × 12 mm [width × length]); thus, lung metastasis was suspected. On the 536th day, anorexia and lethargy occurred, and the dog was lost to follow-up. Discussion: In the present case, local recurrence of TC was suspected based on cervical US. Although US was useful as a screening tool, additional examinations were necessary for evaluating local invasiveness, malignancy, and nodal/distant metastasis. FDG-PET can detect recurrence at an early stage because it can sense increased tumor metabolism through physiologic absorption of FDG, even before the beginning of anatomic change in the lesion. Therefore, FDG-PET can assist in treatment planning and provide better prognosis. In humans, focal FDG uptake and a high maximum SUV in the thyroid gland on FDG-PET were associated with a higher risk of cancer. Because there was no evidence of neoplasia except the thyroid lesion during the FDG-PET examination, the tumor showed an increasingly malignant pattern of the thyroid gland on US during the follow-up period, and the metastatic pulmonary nodules were identified on the 650th day after the thyroidectomy, the present case was diagnosed as recurrent TC. This report describes the use of FDG-PET for diagnosing local recurrence of TC, pointing to FDG-PET as a potential strategy to evaluate loco-regional recurrence and distant metastasis of TC.

Thyroidectomy associated with chemotherapy in a dog presenting carcinoma in the thyroid gland / Tireoidectomia associada à quimioterapia em cão com carcinoma na glândula tireóide

This study aimed to describe a case of compact thyroid carcinoma in a dog, emphasizing the diagnosis, treatment, and clinical evolution. An 11-year-old mixed-breed male canine was attended at a private clinic, complaining of swelling in the ventral cervical region and difficulty breathing. A mass close to the thyroid gland was observed in the cervical ultrasound and a mixed tumor was identified by cytology. Based on follow-up exams, the therapeutic approach to be adopted was determined: total surgical resection of the right portion of the thyroid gland, together with the parathyroid glands, followed by chemotherapy with doxorubicin. The histopathology of the tissue removed confirmed the compact thyroid carcinoma. After thyroid removal, signs of hypothyroidism were confirmed by the hormonal dosage and the canine received hormone replacement with Levothyroxine as treatment, ceasing the symptoms. During routine follow-up, the presence of miliary pulmonary metastases was identified. The patient continued with the chemotherapy sessions, presenting a stable condition for almost 6 months after starting the treatment. However, clinical signs of dyspnea were manifested, resulting in a gradual worsening. Thus, the tutors chose to euthanize the animal after 9 months of treatment. According to the case described, thyroidectomy is an option of treatment for cases of thyroid carcinoma with wide dimensions. However, the technique's success depends on the effective and complete removal of the affected tissue due to the high frequency of metastases and the possible occurrence of secondary hypothyroidism.

Objetivou-se, neste trabalho, descrever um caso de carcinoma compacto de tireoide em cão, enfatizando o diagnóstico, o tratamento e a evolução clínica. O paciente foi atendido em uma clínica particular, sendo um canino macho, sem raça definida, de 11 anos, com queixa de edema cervical ventral e dificuldade respiratória. Pela ultrassonografia cervical, foi observada uma massa próxima à glândula tireoide e pela citologia, um tumor misto. A partir dos exames de acompanhamento, foi determinada a conduta terapêutica a ser adotada: ressecção cirúrgica total da porção direita da glândula tireoide, junto às paratireoides, seguida de quimioterapia com doxorrubicina. A histopatologia do tecido removido confirmou o carcinoma compacto da tireoide. Após a remoção da tireoide, sinais de hipotireoidismo foram confirmados pela dosagem hormonal, sendo feita reposição hormonal com Levotiroxina, cessando os sintomas. Durante o acompanhamento de rotina, foi identificada a presença de metástase pulmonar miliar. O paciente continuou suas sessões de quimioterapia, mantendo um quadro estável por quase seis meses após o início do tratamento. No entanto, sinais clínicos de dispneia foram manifestados, com piora gradativa do quadro, tendo os tutores optado pela eutanásia do animal após nove meses do início do tratamento. De acordo com o exposto, conclui-se que a tireoidectomia é um tratamento de escolha para os casos de carcinoma de tireoide com amplas dimensões. Entretanto, o sucesso da técnica depende da remoção efetiva e completa do tecido afetado, devido à alta frequência de metástases, além de poder ser acompanhada por um quadro de hipotireoidismo secundário.

Hemitireoidectomia por carcinoma em equino / Equine carcinoma hemithyroidectomy

Background: In horses, the thyroid gland is located slightly caudal to the larynx and dorsolaterally between the third and sixth tracheal ring, adjacent to the thyroid, there are four small glands called parathyroid glands. In the clinical routine of horses, thyropathies are difficult to be diagnosed, as they have a silent evolution. Thyroid neoplasia is the most common finding in horses, usually unilateral and normally present in older animals. The present study reports a case of equine thyroid carcinoma and its systemic clinical effects, which was successfully treated by means of hemitieroidectomy. Case: A 12-year-old male mixed breed horse weighing 436 kg, was admitted to the Veterinary Medical Teaching Hospital of the FZEA/USP with the main complaint of volume increase in the right ventrolateral region of the neck, difficulty in swallowing, significant weight loss and weakness of the pelvic limbs. On inspection, there was an increase in volume in the topographic region of the thyroid gland and on palpation, there was a firm mass, with delimited edges, with a smooth, mobile surface, without increasing the temperature and without pain. The animal was sent for ultrasound examination, which revealed a delimited mass, with an apparent capsule around it, differentiated and disorganized cellularity with small hypoechoic points of liquid inside the structure, with no apparent vascularization inside the mass. These findings, associated with the anatomical location of the mass, were consistent with thyroid tissue. The clinical signs commonly observed in thyroid neoformations are respiratory stridor, decreased performance, difficulty in swallowing and suffocation. As there was a compromised diet and weight gain, as well as athletic performance, he chose to have a hemithyroidectomy. After surgery, histopathology of the tissue was performed and thyroid carcinoma was diagnosed. Postoperatively, the animal was medicated with antibiotics, anti-inflammatory and anti-tetanus serum, after 10 days the stitches were removed and the animal was discharged. Discussion: Neoplasia is the most frequent cause of progressive thyroid growth and in case of suspicion of thyroid disorders, thin needle aspiration (FNAB) is recommended and, later, histopathological examination, which is considered the gold standard for diagnosis pathologies of the thyroid gland. In the present case, no FNAB or preoperative histopathological examination was performed due to the time required to obtain the result, associated with difficulty in swallowing and significant weight loss, which required immediate removal of the mass. Considering that the ultrasound examination revealed the absence of noble structures or important vascularization very close to or adhered to the mass, its removal prior to the histopathological examination was indicated. As there was compromised feeding and weight gain, he opted for hemithyroidectomy, the recommended treatment for unilateral tumors in horses. When performing a hemithyroidectomy, it should be remembered that the parathyroid glands accompany the thyroid and are located in its posterior portion, in the pre tracheal region, with its variable final position. With this variation in topography, the identification of parathyroid glands becomes challenging and, consequently, after thyroidectomy, a portion of parathyroid glands stops operating, and this fact is marked clinically by hypocalcemia and its consequences. In this case described, in which the animal had a tumor in thyroid tissue, possibly the parathyroid functions were also altered, which probably reflected in the lameness in the pelvic limbs. It is concluded that partial hemithyroidectomy in horses is an easy procedure to perform and has favorable results in relation to prognosis and quality of life.

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)

Thyroidectomy with parathyroid implantation: is it an easy technique?

Background: Feline hyperthyroidism is the most common endocrine disorder in cats. Cats may not reach the diseasecontrol and/or have side effects with medical therapy. Thyroidectomy is a definitive treatment and the only option whenradioactive iodine is not available. Extracapsular thyroidectomy with transplantation of the external parathyroid gland isthe surgical technique that minimizes the risk of postoperative hypocalcemia when it is compared to others. The aim ofthis study is report the difficulty in visualizing parathyroid gland during extracapsular thyroidectomy with transplantationof the external parathyroid gland technique in hyperthyroid cats.Materials, Methods & Results: Thirty hyperthyroid cats were evaluated and submitted to extracapsular thyroidectomywith transplantation of the external parathyroid gland. Blood samples were collected to hematologic, biochemical andhormonal (total thyroxine) analysis. On physical examination, at least one cervical thyroid lobe was palpable. Cats weretreated with methimazole. Thyroidectomy was recommended when adverse effects of medication occurred or medicalhormonal stabilization was not achieved. The excised thyroid and a sample of external parathyroid gland were histologically examined. Thirteen castrated males and seventeen spayed female cats in age ranging from eight to nineteen years(mean age 13.3 years) were indicated to surgery. Twenty three cats were Brazilian domestic short hair, six were Siameseand one was Oriental. Thyroid palpable cervical nodule was unilateral in eight cats and bilateral in twenty two cats. Thereasons for surgery included adverse effects of methimazole (14/30), difficulty in medicating, owners interest in surgicaltreatment (6/30) and inability to stabilize with medical management (10/30). None developed any anesthetic or postoperative complications. The...(AU)

Thyroidectomy with parathyroid implantation: is it an easy technique?

Background: Feline hyperthyroidism is the most common endocrine disorder in cats. Cats may not reach the diseasecontrol and/or have side effects with medical therapy. Thyroidectomy is a definitive treatment and the only option whenradioactive iodine is not available. Extracapsular thyroidectomy with transplantation of the external parathyroid gland isthe surgical technique that minimizes the risk of postoperative hypocalcemia when it is compared to others. The aim ofthis study is report the difficulty in visualizing parathyroid gland during extracapsular thyroidectomy with transplantationof the external parathyroid gland technique in hyperthyroid cats.Materials, Methods & Results: Thirty hyperthyroid cats were evaluated and submitted to extracapsular thyroidectomywith transplantation of the external parathyroid gland. Blood samples were collected to hematologic, biochemical andhormonal (total thyroxine) analysis. On physical examination, at least one cervical thyroid lobe was palpable. Cats weretreated with methimazole. Thyroidectomy was recommended when adverse effects of medication occurred or medicalhormonal stabilization was not achieved. The excised thyroid and a sample of external parathyroid gland were histologically examined. Thirteen castrated males and seventeen spayed female cats in age ranging from eight to nineteen years(mean age 13.3 years) were indicated to surgery. Twenty three cats were Brazilian domestic short hair, six were Siameseand one was Oriental. Thyroid palpable cervical nodule was unilateral in eight cats and bilateral in twenty two cats. Thereasons for surgery included adverse effects of methimazole (14/30), difficulty in medicating, owners’ interest in surgicaltreatment (6/30) and inability to stabilize with medical management (10/30). None developed any anesthetic or postoperative complications. The...

PTH and ionized calcium evaluation in unilateral thyroidectomized cats / Avaliação de cálcio ionizado e paratormônio em gatos submetidos a tireoidectomia unilateral

The aim of this study was to measure ionized calcium and intact parathormone concentrations after unilateral thyroidectomy with parathyroid autotransplantation in hyperthyroid cats. Hiperthyroid cats may have calcium homeostasis disorder and have decreased calcium concentration. Calcium levels decrease after thyroidectomy and their levels must be measured before thyroidectomy. Seventeen hyperthyroid cats with palpable nodules were submitted to clinical and laboratorial examination and they were prepared to surgery. Unilateral thyroidectomy with parathyroid gland autotransplantation was performed. Concentrations of serum urea, creatinine, alkaline phosphatase, alanine aminotransferase, phosphorus, potassium, total thyroxine and hematologic profile were determined before and seven days after surgery. Blood samples for serum ionized calcium concentration were collected before and after surgery on days 1, 2, 7, 15, 21. Serum calcium concentration fell significantly in all cats within 24 hours after surgery. Hypocalcemia occurred in two cats without clinical signs. The iPTH concentration measurements for samples throughout the study were uniformly low, with no patterns or trends identified. There wasnt correlation between serum calcium levels and iPTH levels in any moment before and after surgery. iPTH couldnt indicate parathyroid gland function after thyroidectomy in cats. The resultsof this study suggest that calcium concentration of all thyroidectomized cats must be measured before surgery even if they are submitted to unilateral thyroidectomy. iPTH concentration doenst evaluate patathyroid gland function.(AU)

O objetivo deste estudo é avaliar as concentrações de cálcio ionizado e paratormônio intacto (iPTH) após a tireoidectomia com implantação da paratireoide em gatos hipertireoideos. Gatos hipertireoideos podem apresentar hipocalcemia por apresentarem distúrbio na homeostase de cálcio. A tireoidectomia pode levar a hipocalcemia pós-operatória, sendo, portanto, fundamental a mensuração dos níveis de cálcio antes da cirurgia em pacientes hipertireoideos. Dezessete gatos com hipertireoidismo com lobos cervicais palpáveis foram examinados e avaliados laboratorialmente para a cirurgia. Tireoidectomia unilateral com implantação da glândula paratireoide foi realizada. Hemograma completo, ureia, creatinina, fosfatase alcalina, alanino aminotransferase, fósforo, potássio e tiroxina total foram realizados antes e sete dias após a cirurgia. Amostras de sangue para avaliar cálcio ionizado e paratormônio intacto foram coletadas antes e nos dias 1, 2, 7, 15 e 21 após a cirurgia. Os níveis séricos de cálcio diminuíram significativamente em 24 horas após a cirurgia. Hipocalcemia subclínica ocorreu em dois gatos. As concentrações de iPTH foram uniformemente baixas ao longo do estudo e não avaliaram a função da glândula paratireoide após a tireoidectomia nesses gatos. Não houve correlação entre os níveis de cálcio e de iPTH. Os resultados deste estudo sugerem que os níveis de iPTH não indicam função da glândula paratireoide e que os níveis de cálcio devem ser avaliados antes da tireoidectomia, mesmo nos casos de tireoidectomia unilateral.(AU)

Osteossarcoma osteoblástico primário em glândula tireoide de cão da raça rotweiller - relato de caso / Primary osteoblastic osteosarcoma in the thyroid gland of a rottweiler - a case report / Osteosarcoma osteoblástico primario de tiroides en Rottweiler - relato de caso

Osteossarcoma extraesquelético em cães é um tipo raro de câncer ósseo,com capacidade de acometer outros órgãos e tecidos epiteliais. Este estudotem como objetivo relatar o caso de um cão macho da raça rotweiller comosteossarcoma extraesquelético em glândula tireoide e evolução de três meses, desde a sua manifestação clínica. Durante a consulta , foi realizada radiografia do pescoço para avaliar a extensão do tumor. Foram feitas também radiografia do tóraxe ultrassonografia abdominal, sendo ambas negativas para metástase. O material do tumor foi colhido por citologia aspirativa, sendo sugestivo para osteossarcoma. Após 25 dias, o paciente foi submetido ao procedimento cirúrgico para tireoidectomia total; no entanto, veio a óbito após o término da cirurgia, devido a complicaçõescardio/respiratórias. Foi realizada a necropsia, sendo constatada a presença de nódulos na pleura e no pulmão compatíveis com metástase. O diagnóstico foi confirmado posteriormente por meio do exame histopatológico, o que caracterizou um quadro raro de câncer em cães.

Extraskeletal osteosarcoma is a rare type of bone cancer in dogs, and canaffect other organs and epithelial tissues. This study reports the case of a male rottweiler presenting a three-month history of extraskeletal osteosarcoma in the thyroid gland. Neck radiography was performed to assess tumor extension, as well as chest and abdominal ultrasonography, which were negative for metastasls . Aspirationcytology of tumor material was suggestive of osteosarcoma. After 25 days, the patient underwent total thyroidectomy, but passed away after surgery completion due to cardiorespiratory complications. Necropsy confirmed the presence of nodules in the pleura and lung that were consistent with metastasis. Histopatholoqical examinationlater confirmed the diagnosis of a rare case of cancer in dogs.

El osteosarcoma extraesquelético del perro es un tipo raro de cânceróseo, que puede afectar otros órganos y tejidos epiteliates. Este trabajo tiene como objetivo relatar el caso de un perro macho de raza Rottweiler que presento un osteosarcoma extraesquelético en la glándula tiroides con evolución de tres mesesdesde su manifestación clínica. Durante la consulta se realizó una radiografia delcuello a fin de evaluar la extensión del tumor. Se realizaron también radiografías de tórax y ecografía abdominal, aunque ambos exámenes fueron negativos en relacióna la presencia de metástasis. Se realizó una punción aspirativa, y el material enviado para examen fue sugestivo de osteosarcoma. Veinticinco días después el paciente entró en cirugía, en la que se realizó una tiroidectomía total. No obstante, el mismo murió después del procedimiento quirúrgico debido a complicaciones cardiorrespiratorias.En la necropsia se pudo comprobar la presenda de nódulos en la pleura y en el pulmón compatibles con metástasis. El diagnóstico se comprobó por exámenes histopatológicos, confirmando la presencia de un cuadro raro de cáncer en perros.

Osteossarcoma osteoblástico primário em glândula tireoide de cão da raça rotweiller - relato de caso / Primary osteoblastic osteosarcoma in the thyroid gland of a rottweiler - a case report / Osteosarcoma osteoblástico primario de tiroides en Rottweiler - relato de caso

Osteossarcoma extraesquelético em cães é um tipo raro de câncer ósseo,com capacidade de acometer outros órgãos e tecidos epiteliais. Este estudotem como objetivo relatar o caso de um cão macho da raça rotweiller comosteossarcoma extraesquelético em glândula tireoide e evolução de três meses, desde a sua manifestação clínica. Durante a consulta , foi realizada radiografia do pescoço para avaliar a extensão do tumor. Foram feitas também radiografia do tóraxe ultrassonografia abdominal, sendo ambas negativas para metástase. O material do tumor foi colhido por citologia aspirativa, sendo sugestivo para osteossarcoma. Após 25 dias, o paciente foi submetido ao procedimento cirúrgico para tireoidectomia total; no entanto, veio a óbito após o término da cirurgia, devido a complicaçõescardio/respiratórias. Foi realizada a necropsia, sendo constatada a presença de nódulos na pleura e no pulmão compatíveis com metástase. O diagnóstico foi confirmado posteriormente por meio do exame histopatológico, o que caracterizou um quadro raro de câncer em cães.(AU)

Extraskeletal osteosarcoma is a rare type of bone cancer in dogs, and canaffect other organs and epithelial tissues. This study reports the case of a male rottweiler presenting a three-month history of extraskeletal osteosarcoma in the thyroid gland. Neck radiography was performed to assess tumor extension, as well as chest and abdominal ultrasonography, which were negative for metastasls . Aspirationcytology of tumor material was suggestive of osteosarcoma. After 25 days, the patient underwent total thyroidectomy, but passed away after surgery completion due to cardiorespiratory complications. Necropsy confirmed the presence of nodules in the pleura and lung that were consistent with metastasis. Histopatholoqical examinationlater confirmed the diagnosis of a rare case of cancer in dogs.(AU)

El osteosarcoma extraesquelético del perro es un tipo raro de cânceróseo, que puede afectar otros órganos y tejidos epiteliates. Este trabajo tiene como objetivo relatar el caso de un perro macho de raza Rottweiler que presento un osteosarcoma extraesquelético en la glándula tiroides con evolución de tres mesesdesde su manifestación clínica. Durante la consulta se realizó una radiografia delcuello a fin de evaluar la extensión del tumor. Se realizaron también radiografías de tórax y ecografía abdominal, aunque ambos exámenes fueron negativos en relacióna la presencia de metástasis. Se realizó una punción aspirativa, y el material enviado para examen fue sugestivo de osteosarcoma. Veinticinco días después el paciente entró en cirugía, en la que se realizó una tiroidectomía total. No obstante, el mismo murió después del procedimiento quirúrgico debido a complicaciones cardiorrespiratorias.En la necropsia se pudo comprobar la presenda de nódulos en la pleura y en el pulmón compatibles con metástasis. El diagnóstico se comprobó por exámenes histopatológicos, confirmando la presencia de un cuadro raro de cáncer en perros.(AU)

Complicações pós-operatórias em gatos hipertireoideos submetidos / à tireoidectomia unilateral / Unilateral thyroidectomy complications in hyperthyroid cats

Gatos com hipertireoidismo podem se beneficiar do tratamento cirúrgico em algumas situações, como em casos de neoplasias e intolerância a medicação. Várias técnicas já foram descritas sendo a tireoidectomia com implantação da glândula paratireóide em etapas a que mais minimiza o risco de hipocalcemia pós-cirúrgica. Este trabalho teve como objetivo avaliar as possíveis complicações pós-operatórias em gatos com hipertireoidismo submetidos à técnica de tireoidectomia unilateral com implantação da glândula paratireóide. Oito gatos com diagnóstico clínico e laboratorial de hipertireoidismo foram operados e seus níveis de cálcio ionizado avaliados com 24 e 48 horas, sete, quinze e 21 dias após a cirurgia. Resultados de exames laboratoriais (hemograma, ureia, creatinina, e tiroxina total) foram coletados sete dias após a cirurgia e comparados com os resultados obtidos no pré-operatório. Uma Análise de Variância (ANOVA One-Way) e o teste de Scheffe foram utilizados para avaliar os resultados do cálcio ionizado, enquanto que para a análise dos resultados da creatinina foi utilizado o teste t de Student (p<0,05). Não foram observadas alterações clínicas ou nos níveis de cálcio após a cirurgia e, apesar dos níveis de cálcio após a cirurgia terem diminuído, essa variação não foi significativa (p=0,149). Os níveis séricos de creatinina aumentaram significativamente (p=0,026). Estes resultados sugerem que a técnica descrita é segura e que pode ser curativa em determinados casos de hipertireoidismo felino sem doença renal prévia.

Thyroid neoplasia is the primary indication for thyroidectomy in cats. Several techniques for thyroidectomy in cats have been described, but a simplified extracapsular thyroidectomy that includes transplantation of the parathyroid gland minimizes the risk of postoperative parathyroid failure resulting in life-threatening hypocalcemia. The aim of this study was to evaluate the outcomes of unilateral thyroidectomy with parathyroid gland transplantation in hyperthyroid cats. Eight cats were determined to be hyperthyroid based upon physical examination and laboratorial panel and were treating by surgery. The cats were evaluated on days 1, 2, 7, 15 and 21 after the surgery, including blood draw for serum ionized calcium testing. On day 7, serum creatinine and total thyroxine testing was also performed. To test for differences between the means of pre and post treatment, ANOVA One-Way and Scheffe test were performed to evaluate ionized calcium and Student test used to evaluate serum creatinina. A P value of <0.05 was considered to indicate statistical significance. Surgical complications were not observed. Comparison of the pre- and post-surgical ionized calcium level indicated no significant difference (p=0,149). However, there was a significant increase in serum creatinine concentration (p=0.026). Unilateral thyroidectomy with parathyroid gland transplantation was effective and safe for hyperthyroid cats with gland unilateral involvement without renal disease.

Complicações pós-operatórias em gatos hipertireoideos submetidos / à tireoidectomia unilateral / Unilateral thyroidectomy complications in hyperthyroid cats

Gatos com hipertireoidismo podem se beneficiar do tratamento cirúrgico em algumas situações, como em casos de neoplasias e intolerância a medicação. Várias técnicas já foram descritas sendo a tireoidectomia com implantação da glândula paratireóide em etapas a que mais minimiza o risco de hipocalcemia pós-cirúrgica. Este trabalho teve como objetivo avaliar as possíveis complicações pós-operatórias em gatos com hipertireoidismo submetidos à técnica de tireoidectomia unilateral com implantação da glândula paratireóide. Oito gatos com diagnóstico clínico e laboratorial de hipertireoidismo foram operados e seus níveis de cálcio ionizado avaliados com 24 e 48 horas, sete, quinze e 21 dias após a cirurgia. Resultados de exames laboratoriais (hemograma, ureia, creatinina, e tiroxina total) foram coletados sete dias após a cirurgia e comparados com os resultados obtidos no pré-operatório. Uma Análise de Variância (ANOVA One-Way) e o teste de Scheffe foram utilizados para avaliar os resultados do cálcio ionizado, enquanto que para a análise dos resultados da creatinina foi utilizado o teste t de Student (p<0,05). Não foram observadas alterações clínicas ou nos níveis de cálcio após a cirurgia e, apesar dos níveis de cálcio após a cirurgia terem diminuído, essa variação não foi significativa (p=0,149). Os níveis séricos de creatinina aumentaram significativamente (p=0,026). Estes resultados sugerem que a técnica descrita é segura e que pode ser curativa em determinados casos de hipertireoidismo felino sem doença renal prévia.(AU)

Thyroid neoplasia is the primary indication for thyroidectomy in cats. Several techniques for thyroidectomy in cats have been described, but a simplified extracapsular thyroidectomy that includes transplantation of the parathyroid gland minimizes the risk of postoperative parathyroid failure resulting in life-threatening hypocalcemia. The aim of this study was to evaluate the outcomes of unilateral thyroidectomy with parathyroid gland transplantation in hyperthyroid cats. Eight cats were determined to be hyperthyroid based upon physical examination and laboratorial panel and were treating by surgery. The cats were evaluated on days 1, 2, 7, 15 and 21 after the surgery, including blood draw for serum ionized calcium testing. On day 7, serum creatinine and total thyroxine testing was also performed. To test for differences between the means of pre and post treatment, ANOVA One-Way and Scheffe test were performed to evaluate ionized calcium and Student test used to evaluate serum creatinina. A P value of <0.05 was considered to indicate statistical significance. Surgical complications were not observed. Comparison of the pre- and post-surgical ionized calcium level indicated no significant difference (p=0,149). However, there was a significant increase in serum creatinine concentration (p=0.026). Unilateral thyroidectomy with parathyroid gland transplantation was effective and safe for hyperthyroid cats with gland unilateral involvement without renal disease.(AU)

Oxidant/antioxidant balance in patients with thyroid cancer

PURPOSE: To compare the antioxidant enzyme activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the levels of lipid peroxidation product malondialdehyde (MDA) in blood samples of thyroid cancer patients compared to healthy controls. METHODS: 43 control subjects (mean age 44±13 years) and 43 patients (43±13 years) presented with multinodular goiter whose fine needle aspiration revealed malignant cytology were included into this study. The SOD, MDA and GSH-Px activities were measured in control subjects, and before/20 days after thyroidectomy in thyroid cancer patients. RESULTS: SOD activities of pre-thyroidectomy, post-thyroidectomy and control groups were not different (p>0.05). Before thyroidectomy GSH-Px activities were lower (p<0.05) and MDA levels were higher (p<0.05) than the control group. In post- thyroidectomy, GSH-Px activity (p<0.05) increased, and MDA levels (p<0.05) decreased compared to prethyroidectomy levels. After thyroidectomy GSH-Px activity was significantly higher than the control group (p<0.05). Although post-thyroidectomy MDA levels significantly decreased, they were still higher than the control group (p<0.05). CONCLUSION: The superoxide dismutase does not seem to change with thyroid cancer and thyroidectomy but both antioxidant glutathione peroxidase and lipid peroxidation product malondialdehyde do. These preliminary findings may point out oxidant/antioxidant imbalance associated with thyroid cancer.(AU)

The influence of hypothyroidism on liver regeneration: an experimental study in rats / A influência do hipotireoidismo na regeneração hepatica: estudo experimental em ratos

BACKGROUND: The influence of hypothyroidism in liver regeneration has been a controversial opinions. PURPOSE: The aim of this study is to identify the relationship between hypothyroidism and liver regeneration in rats. METHODS: Forty male Wistar rats divided into two groups of 20 specimens each. One group (C) consisted of euthyroid rats, and the other (H) of hypothyroid rats. All the animals were anesthetized with xylazine and ketamine and subjected to a longitudinal incision in the anterior cervical region. The thyroid was completely resected in group H and left intact in group C. Ten days after the first surgery, both groups of rats were weighed and submitted to partial hepatectomy, in which the left lateral and median lobes were resected and weighed. Examinations were carried out after 24 hours and, on day 7, using 3 methods: KWON et al.'s formula to identify increase in volume; mitotic figure count in five fields; and the percentage of PCNA-positive nuclei in five fields. RESULTS: Using KWON's formula, the regeneration rate for Group C after 24 hours was 58.49 percent whereas that for Group H was 50.42 percent (p=0.0165). After 7 days, the regeneration rate for Group C was 93.04 percent and Group H 93.74 percent (p=0.2165). The average number of mitotic figures after 24 hours was 14 ± 1.5 for Group C and 9.8 ± 2.2 for Group H (p=0,00016). After 7 days the corresponding figures were 5.4 ± 1.1 and 5.1 ± 1.2 (p=0,6343). The average number of PCNA-positive nuclei after 24 hours was 13.55 ± 3.84 in Group C and 7.7 ± 2.11 in Group H (p =0,0006)). The corresponding figures after 7 days were 3.5 ± 2.39 for Group C and 4.11 ± 1.90 for Group H (p>0.05). CONCLUSION: We conclude that hypothyroidism in rats causes a delay in hepatic regeneration in the first 24 hours, but that after seven days the rate of regeneration is equal to that in euthyroid rats.(AU)

BACKGROUND: A influência do hipotireoidismo na regeneração hepatica tem opiniões controvérsas. OBJETIVO: Identificar a relação entre o hipotireoidismo e a regeneração hepatica, em ratos. MÉTODOS: Quarenta ratos Wistar, machos, divididos em dois grupos de 20 animais. Um grupo (C) constituído de ratos eutireoideanos e outro (H) de ratos hipotireoideanos. Todos os animais foram anestesiados com xilasina e quetamina e submetidos a uma incisão cervical longitudinal. A tireóide foi completamente ressecada no animais do grupo H e deixada intacta no grupo C. Dez dias após a primeira intervenção ambos os grupos de ratos foram pesados e submetidos à hepatectomia parcial, retirando-se os lobos lateral esquerdo e mediano, que foram pesados. Foram examinados com 24 horas e com 7 dias usando-se 3 métodos: formula de KWON et al. que identifica o aumento de volume; contagem de figures de mitose em cinco campos e de núcleos PCNA positivos em cinco campos. RESULTOS: Usando a formula de KWON et al. a taxa de regeneração do grupo C, após 24 horas, foi de 58.49 por cento enquanto que a do grupo H foi de 50.42 por cento (p=0.0165). Após 7 dias, a taxa de regeneração no grupo C foi de 93.04 por cento e do grupo H 93.74 por cento (p=0.2165). A média de figures de mitose após 24 horas foi de 14 ± 1.5 no grupo C e de 9.8 ± 2.2 no groupo H (p=0,00016). Após 7 dias foi de 5.4 ± 1.1 e 5.1 ± 1.2 (p=0,6343). A média de núcleos PCA positivos, após 24 horas, foi de 13.55 ± 3.84 no grupo C e 7.7 ± 2.11 no grupo H (p =0,0006)). Com 7 dias foi de 3.5 ± 2.39 no groupo C e de 4.11 ± 1.90 for Group H (p>0.05). CONCLUSÃO: Concluiu-se que o hipotireoidismo, em ratos, causa atraso da regeneração hepatica nas primeiras 24 horas, mas após 7 dias a regeneração se equivale à dos ratos eutireoideanos.(AU)

Causas de hipertireoidismo em gatos submetidosa tireoidectomia / Causes of hyperthyroidism in cats submitted to thyroidectomy

O hipertireoidismo é a doença endócrina mais comum em gatos e geralmente é causada por adenomatireoidiano. O tratamento pode ser clínico, cirúrgico ou por radioiodoterapia. Vinte e quatro gatoscom hipertireoidismo e nódulos cervicais palpáveis, independente da raça, sexo, idade ou raça, foramsubmetidos ao tratamento cirúrgico. O histórico, anamnese, examesclínico e laboratoriais foramrealizados. Os pacientes foram estabilizados com medicação oral e submetidos àtireoidectomia comimplantação da glândula paratireóide no músculo esterno-hióideo. Os gatos eram de meia-idade aidosos, não havendo predisposição de sexo ou raça, sendo dezoito sem raça definida, quatro siameses,um Oriental e um persa. A glândula paratireóide foi implantada em 12 animais pela dificuldade dalocalização da mesma. Nenhum animal desenvolveu complicação pós-operatória. A histopatologiaidentificou vinte e três animais com adenoma tireoidiano e um com carcinoma. A cirurgia é seguracomo tratamento para hipertireoidismo em gatos sem complicações pós-operatórias. O adenoma é acausa mais comum de hipertireoidismo em gatos.(AU)

Hyperthyroidism is the most common endocrine disease in cats andis usually caused by thyroidadenoma.It can be treatedby clinical, surgical or radioiodinetreatment. Twenty four cats with hyperthyroidismwith palpable thyroid lobes in the neck underwent surgical treatment, regardless of sex,age, or breed.The history, anamnesis, general clinical examination and laboratory tests were performed.Animals were stabilized by oral medication and submitted to thyroidectomy with parathyroidgland transplantation in sternohyoid muscle. The animals were middle-aged to elderly, with no genderpredilection, and there were eighteen Domestic Shorthairs, four Siamese cats, one Persian andone Oriental. The parathyroid gland was transplanted in only twelve animals because in the others itwas not identified. No animal developed postoperative complications.Histopathology of the twentythree animals showed presence of thyroid adenoma and one carcinoma. Surgery is safe asa definitivetreatment for hyperthyroidism in hyperthyroid cats without serious complications. Adenoma is themost important cause of hyperthyroidism in cats.(AU)

Causas de hipertireoidismo em gatos submetidosa tireoidectomia / Causes of hyperthyroidism in cats submitted to thyroidectomy

O hipertireoidismo é a doença endócrina mais comum em gatos e geralmente é causada por adenomatireoidiano. O tratamento pode ser clínico, cirúrgico ou por radioiodoterapia. Vinte e quatro gatoscom hipertireoidismo e nódulos cervicais palpáveis, independente da raça, sexo, idade ou raça, foramsubmetidos ao tratamento cirúrgico. O histórico, anamnese, examesclínico e laboratoriais foramrealizados. Os pacientes foram estabilizados com medicação oral e submetidos àtireoidectomia comimplantação da glândula paratireóide no músculo esterno-hióideo. Os gatos eram de meia-idade aidosos, não havendo predisposição de sexo ou raça, sendo dezoito sem raça definida, quatro siameses,um Oriental e um persa. A glândula paratireóide foi implantada em 12 animais pela dificuldade dalocalização da mesma. Nenhum animal desenvolveu complicação pós-operatória. A histopatologiaidentificou vinte e três animais com adenoma tireoidiano e um com carcinoma. A cirurgia é seguracomo tratamento para hipertireoidismo em gatos sem complicações pós-operatórias. O adenoma é acausa mais comum de hipertireoidismo em gatos.

Hyperthyroidism is the most common endocrine disease in cats andis usually caused by thyroidadenoma.It can be treatedby clinical, surgical or radioiodinetreatment. Twenty four cats with hyperthyroidismwith palpable thyroid lobes in the neck underwent surgical treatment, regardless of sex,age, or breed.The history, anamnesis, general clinical examination and laboratory tests were performed.Animals were stabilized by oral medication and submitted to thyroidectomy with parathyroidgland transplantation in sternohyoid muscle. The animals were middle-aged to elderly, with no genderpredilection, and there were eighteen Domestic Shorthairs, four Siamese cats, one Persian andone Oriental. The parathyroid gland was transplanted in only twelve animals because in the others itwas not identified. No animal developed postoperative complications.Histopathology of the twentythree animals showed presence of thyroid adenoma and one carcinoma. Surgery is safe asa definitivetreatment for hyperthyroidism in hyperthyroid cats without serious complications. Adenoma is themost important cause of hyperthyroidism in cats.

Tireoidectomia extracapsular com transplante de paratireóide em felino - Relato de caso / Feline Extracapsular Thyroidectomy with Parathyroid Gland Tranplantation - Case

O presente relato descreve um caso de hipertireoidismo felino em um paciente, macho, com 16 anos,que apresentava como sinais clínicos principais emaciação, polifagia e vômitos. O animal inicialmentefoi tratado com metimazol, porém apresentou sinais de intoxicação ao medicamento, com episódioseméticos graves. O felino foi submetido, então, a tireoidectomia extracapsular com transplante de paratireóide,uma técnica que promove a cura do animal sem, no entanto, acarretar complicações comoa hipocalcemia(AU)

This report describes a case of hyperthyroidism in a male 16 years old cat, whose mainly symptomswere weight loss, polyphagia and vomiting. The animal was treated with methimazole. Nevertheless,the cat presented signs of intoxication due to medication, with severe emetic episodes. The catundergone to surgery with extracapsular thyroidectomy technique associated with transplantation ofparathyroid gland. This technique promotes cure without complications such as hypocalcaemia(AU)

Tireoidectomia extracapsular com transplante de paratireóide em felino - Relato de caso / Feline Extracapsular Thyroidectomy with Parathyroid Gland Tranplantation - Case

O presente relato descreve um caso de hipertireoidismo felino em um paciente, macho, com 16 anos,que apresentava como sinais clínicos principais emaciação, polifagia e vômitos. O animal inicialmentefoi tratado com metimazol, porém apresentou sinais de intoxicação ao medicamento, com episódioseméticos graves. O felino foi submetido, então, a tireoidectomia extracapsular com transplante de paratireóide,uma técnica que promove a cura do animal sem, no entanto, acarretar complicações comoa hipocalcemia

This report describes a case of hyperthyroidism in a male 16 years old cat, whose mainly symptomswere weight loss, polyphagia and vomiting. The animal was treated with methimazole. Nevertheless,the cat presented signs of intoxication due to medication, with severe emetic episodes. The catundergone to surgery with extracapsular thyroidectomy technique associated with transplantation ofparathyroid gland. This technique promotes cure without complications such as hypocalcaemia

O processo de cicatrização influenciado pelo hipotireoidismo e pelo envelhecimento: estudo da cicatrização da parede abdominal, em ratos

PURPOSE: Hypothyroidism is a common situation among the aged which affects protein synthesis. The objective of the present study was to determine the influence of hypothyroidism on the healing process in aged rats. METHODS: 96 male Wistar rats were used, 48 of them with a mean age of 110 days and 48 with a mean age of 750 days. Half the young animals and half the old ones were euthyroid and half were hypothyroid. Hypothyroidism was obtained by total thyroidectomy. Thirty days after surgery the animals were submitted to median laparotomy followed by laparorrhaphy on 2 synthesis planes. Six animals from each group were submitted to euthanasia by drawing lots on the 3rd, 7th and 14th postoperative day and submitted to macroscopic, resistance, and histopathological analysis. RESULTS: The resistance of the skin scars was lower in hypothyroid animals, both the young (p=0.0145) and old (p=0.0242) ones, with no significant relation with age being detected. The resistance of the scars on the peritoneum-muscle-aponeurosis plane was lower in old animals on the 24th day (p=0.0014) and even lower in hypothyroid old animals (p=0.0000). The histological evolution was similar, but differences in collagen presence were observed. On the 7th day the skin scars had a lower collagen content in young (p=0.0201) and old (p=0.0003). hypothyroid animals. On the 14th day the scars of old hypothyroid animals had less collagen than those of normal old animals (p=0.0092) and those of young hypothyroid animals (p=0.0283). On the 3rd day, the scars of hypothyroid animals on the peritoneum-muscle-aponeurosis plane presented less collagen than those of both young (p=0.0089) and old (p=0.0171) normal controls, but there was no relation with age. This association persisted on the 7th and 17th day, but age dependence was observed at these time points. CONCLUSION: Analysis of the results permits us to conclude that healing is impaired in the presence of hypothyroidism and worsens with aging.

OBJETIVO: O hipotireoidismo é uma situação bastante comum nos indivíduos idosos e influencia a síntese protéica. O presente estudo busca conhecer a influência do hipotireoidismo no processo de cicatrização de ratos idosos. MÉTODO: Utilizaram-se 96 ratos Wistar, machos; 48 deles com média de idade de 110 dias e 48 com 760 dias. Metade dos animais jovens e metade dos velhos eram eutireoideanos e metade eram hipotireoideanos. Conseguiu-se o hipotireoidismo por meio de tireoidectomia total. Após 30 dias, fez-se uma laparotomia mediana seguida de laparorrafia com 2 planos de síntese. No 3.º, 7.º e 14.º dias de pós-operatório, sorteados, 6 animais de cada grupo, foram submetidos à eutanásia. Fez-se a análise macroscópica, da resistência e histopatológica. RESULTADOS: A resistência das cicatrizes da pele, foi menor nos animais hipotireoideanos, tanto jovens (p=0,0145), quanto velhos (p=0,0242), não se encontrando relação significante com a idade. A resistência das cicatrizes do plano peritônio-músculo-aponevrótico,foi menor nos animais velhos, no 14.º dia (p=0,0014) e ainda menor quando eram velhos e hipotireoideanos (p=0,0000). A evolução histológica foi semelhante, entretanto, existiram diferenças quanto à presença de colágeno. No 7.º dia as cicatrizes cutâneas apresentavam menor conteúdo de colágeno nos animais hipotireoideanos, jovens(p=0,0201) e velhos (p=0,0003). No 14.º dia as cicatrizes dos velhos hipotireoideanos tinham menos colágeno do que as dos velhos normais (p=0,0092) e menos do que as dos jovens hipotireodeanos (p=0,0283). No plano peritônio-músculo-aponevrótico, no 3.º dia, as cicatrizes dos animais hipotireoideanos apresentavam menos colágeno do que as dos controle normais, tanto jovens (p=0,0089) quanto velhos (p=0,0171), mas não havia relação com a idade. Esta associação se manteve nas avaliações do 7.º e do 14.º dia, porém nestes tempos observou-se dependência da idade. CONCLUSÃO: A análise dos resultados permite concluir que existe prejuízo da cicatrização na presença de hipotireoidismo que é piorada com o envelhecimento.

O processo de cicatrização influenciado pelo hipotireoidismo e pelo envelhecimento: estudo da cicatrização da parede abdominal, em ratos

PURPOSE: Hypothyroidism is a common situation among the aged which affects protein synthesis. The objective of the present study was to determine the influence of hypothyroidism on the healing process in aged rats. METHODS: 96 male Wistar rats were used, 48 of them with a mean age of 110 days and 48 with a mean age of 750 days. Half the young animals and half the old ones were euthyroid and half were hypothyroid. Hypothyroidism was obtained by total thyroidectomy. Thirty days after surgery the animals were submitted to median laparotomy followed by laparorrhaphy on 2 synthesis planes. Six animals from each group were submitted to euthanasia by drawing lots on the 3rd, 7th and 14th postoperative day and submitted to macroscopic, resistance, and histopathological analysis. RESULTS: The resistance of the skin scars was lower in hypothyroid animals, both the young (p=0.0145) and old (p=0.0242) ones, with no significant relation with age being detected. The resistance of the scars on the peritoneum-muscle-aponeurosis plane was lower in old animals on the 24th day (p=0.0014) and even lower in hypothyroid old animals (p=0.0000). The histological evolution was similar, but differences in collagen presence were observed. On the 7th day the skin scars had a lower collagen content in young (p=0.0201) and old (p=0.0003). hypothyroid animals. On the 14th day the scars of old hypothyroid animals had less collagen than those of normal old animals (p=0.0092) and those of young hypothyroid animals (p=0.0283). On the 3rd day, the scars of hypothyroid animals on the peritoneum-muscle-aponeurosis plane presented less collagen than those of both young (p=0.0089) and old (p=0.0171) normal controls, but there was no relation with age. This association persisted on the 7th and 17th day, but age dependence was observed at these time points. CONCLUSION: Analysis of the results permits us to conclude that healing is impaired in the presence of hypothyroidism and worsens with aging.

OBJETIVO: O hipotireoidismo é uma situação bastante comum nos indivíduos idosos e influencia a síntese protéica. O presente estudo busca conhecer a influência do hipotireoidismo no processo de cicatrização de ratos idosos. MÉTODO: Utilizaram-se 96 ratos Wistar, machos; 48 deles com média de idade de 110 dias e 48 com 760 dias. Metade dos animais jovens e metade dos velhos eram eutireoideanos e metade eram hipotireoideanos. Conseguiu-se o hipotireoidismo por meio de tireoidectomia total. Após 30 dias, fez-se uma laparotomia mediana seguida de laparorrafia com 2 planos de síntese. No 3.º, 7.º e 14.º dias de pós-operatório, sorteados, 6 animais de cada grupo, foram submetidos à eutanásia. Fez-se a análise macroscópica, da resistência e histopatológica. RESULTADOS: A resistência das cicatrizes da pele, foi menor nos animais hipotireoideanos, tanto jovens (p=0,0145), quanto velhos (p=0,0242), não se encontrando relação significante com a idade. A resistência das cicatrizes do plano peritônio-músculo-aponevrótico,foi menor nos animais velhos, no 14.º dia (p=0,0014) e ainda menor quando eram velhos e hipotireoideanos (p=0,0000). A evolução histológica foi semelhante, entretanto, existiram diferenças quanto à presença de colágeno. No 7.º dia as cicatrizes cutâneas apresentavam menor conteúdo de colágeno nos animais hipotireoideanos, jovens(p=0,0201) e velhos (p=0,0003). No 14.º dia as cicatrizes dos velhos hipotireoideanos tinham menos colágeno do que as dos velhos normais (p=0,0092) e menos do que as dos jovens hipotireodeanos (p=0,0283). No plano peritônio-músculo-aponevrótico, no 3.º dia, as cicatrizes dos animais hipotireoideanos apresentavam menos colágeno do que as dos controle normais, tanto jovens (p=0,0089) quanto velhos (p=0,0171), mas não havia relação com a idade. Esta associação se manteve nas avaliações do 7.º e do 14.º dia, porém nestes tempos observou-se dependência da idade. CONCLUSÃO: A análise dos resultados permite concluir que existe prejuízo da cicatrização na presença de hipotireoidismo que é piorada com o envelhecimento.

O processo de cicatrização influenciado pelo hipotireoidismo e pelo envelhecimento: estudo da cicatrização de anastomoses intestinais, em ratos

TURPOSE: The aging of the population has led to an increased number of interventions in elderly patients, with hypothyroidism, even at the subclinical level, being a common situation among these patients. The objective of the present study was to determine the influence of hypothyroidism on the healing process of colon anastomoses in aged rats. METHODS: 96 male Wistar rats were used, 48 of them young and 48 old. Half the young animals and half the old ones were euthyroid and half were hypothyroid. Hypothyroidism was obtained by total thyroidectomy. Thirty days after surgery the animals were submitted to median laparotomy followed by transverse colotomy of the left colon with end-to-end anastomosis and laparorrhaphy. Six animals from each group were submitted to euthanasia by drawing lots on the 3rd, 7th and 14th postoperative day and submitted to macroscopic, resistance, and histopathological analysis of the anastomoses. RESULTS: No dehiscence was observed and the gain of resistance and the general histological evolution in terms of epithelialization and inflammatory reaction was similar in all groups. Analysis of total collagen content revealed that the anastomoses of young and old animals showed the same behavior on the 3rd day, although less collagen was observed in hypothyroid animals (YN x YH p=0.0000; ON x OH p=0.0000). This behavior persisted on the 7th and 14th day. Less collagen I was present in the anastomoses of hypothyroid animals on the 3rd (YN x YH p=0.0015; ON x OH p=0.0000), 7th (YN x YH p=0.0006; ON x OH p=0.0001) and 14th day (YN x YH p=0.0181; ON x OH p=0.0057), the same occurring for collagen III on the 3rd (x YH p=0.0007; ON x OH p=0.0260), 7th (YN x YH p=0.0160; ON x OH p=0.2670) and 14th day (YN x YH p=0.0000; ON x OH p=0.0030). CONCLUSION: Analysis of the results permitted us to conclude that lower collagen concentration due to low synthesis and delayed scar maturation in the anastomoses occurred and was much more due to hypothyroidism than to aging.

OBJETIVO: O envelhecimento da população tem feito crescer o número de intervenções em pacientes idosos, sendo o hipotireoidismo, ainda que sub-clínico, é uma situação bastante comum nestes doentes. O presente estudo busca conhecer a influência do hipotireoidismo no processo de cicatrização de anastomoses colônicas em ratos idosos. MÉTODO: Utilizaram-se 96 ratos Wistar, machos; 48 deles jovens e 48 velhos. Metade dos animais jovens e metade dos velhos eram eutireoideanos e metade eram hipotireoideanos. Conseguiu-se o hipotireoidismo por meio de tireoidectomia total. Após 30 dias, fez-se uma laparotomia mediana seguida de colotomia transversa de cólon esquerdo com anastomose término-terminal e laparorrafia. No 3.º, 7.º e 14.º dias de pós-operatório, sorteados, 6 animais de cada grupo, que foram submetidos à eutanásia. Fez-se a análise macroscópica das anastomoses, da resistência e estudo histopatológico. RESULTADOS: Não se detectaram deiscências e o ganho de resistência e a evolução histológica geral, considerando epitelização e reação inflamatória foi semelhante em todos os grupos. A análise do conteúdo total de colágeno revelou, no 3.º dia, que as anastomoses de jovens e velhos tinham o mesmo comportamento, porém via-se menos colágeno nas anastomoses dos animais com hipotireoidismo (JN x JH p=0,0000; VN x VH p=0,0000). Este comportamento se manteve no 7.º e no 14.º dia. A presença de colágeno I era menor nas anastomoses dos animais hipotireoideanos no 3.º dia (JN x JH p=0,0015; VN x VH p=0,0000), no 7.º dia (JN x JH p=0,0006; VN x VH p=0,0001) e no 14.º dia (JN x JH p=0,0181; VN x VH p=0,0057) o mesmo acontecendo com o colágeno III, no 3.º dia (x JH p=0,0007; VN x VH p=0,0260), no 7.º dia (JN x JH p=0,0160; VN x VH p=0,2670) e no 14.º dia (JN x JH p=0,0000; VN x VH p=0,0030). CONCLUSÃO: A análise dos resultados permite concluir que existe diminuição da concentração de colágeno decorrente da baixa da síntese e retardo de maturação das cicatrizes das anastomoses muito mais às custas do hipotireoidismo do que do envelhecimento.