Valor preditivo do exame clínico, cintilografia, ultra-sonografia, citologia aspirativa e tiroglobulina sérica no nódulo tiroideano único atóxico: estudo prospectivo de 110 pacientes tratados cirurgicamente / Predictive value of clinical examination, scintigraphy, aspirative cytology and serum thyroglobulin in the nontoxic solitary thyroid nodule: prospective study of 110 operated patients

Nódulos de tiróide são comuns na prática médica. Para estabelecer o valor preditivo dos diversos testes diagnósticos, estudamos prospectivamente os dados de exame clínico, cintilografia, ultrasonografia, citologia aspirativa e tiroglobulina sérica pré-operatória de 110 pacientes com nódulos operados e os comparamos com o diagnóstico anátomo-patológico da cirurgia. Nos 110 pacientes encontramos à histologia 124 lesões distintas, sendo 106 (85 por cento) benignas e 18 (15 por cento) malignas. Entre as benignas havia 90 bócios colóides (73 por cento), 8 adenomas foliculares (6 por cento), 4 cistos tiroglossos (3 por cento) e outras 4 lesões; entre as malignas havia 16 (13 por cento) carcinomas primários da tiróide (9 papilíferos, 3 foliculares, 3 indiferenciados e 1 medular) e 2 secundários. Entre os testes diagnósticos a citologia aspirativa apresentou os melhores resultados (sensibilidade: 94 por cento, especificidade: 97 por cento), em comparação com a cintilografia (sensibilidade: 89 por cento, especificidade: 21 por cento), ultra-sonografia (sensibilidades entre 60 e 100 por cento e especificidades entre 25 e 69 por cento) e tiroglobulina pré-operatória (sensibilidade: 7 por cento para qualquer valor discriminatório e elevada especificidade). Alguns dados clínicos também apresentaram elevada especificidade, mas baixa sensibilidade, como rouquidão, disfagia, aparecimento de nova lesão, adenomegalia cervical e antecedentes de radiação. Neste estudo prospectivo concluímos que a citologia aspirativa é o melhor método disponível para o diagnóstico dos nódulos de tiróide.

Effect of isovolemic hemodilution with 3% albumin on thrombus formation at venous microanastomosis in rats.

The present investigation was undertaken to evaluate the effect of isovolemic hemodilution with 3% albumin per se on the prevention of microvascular venous thrombosis, using an experimental model in rats mimicking the thrombotic mechanisms similar to those in clinical situations. Male Wistar rats were allocated into two groups of 15 rats each: group 1, the nonhemodiluted group, consisted of animals submitted to microsurgical procedure to induce thrombosis without previous hemodilution; group 2, the hemodiluted group, consisted of animals submitted to microsurgical procedure to induce thrombosis with previous hemodilution. The histopathological examination clearly showed that the nonhemodiluted group presented well-defined venous thrombosis in the anastomoses in 9 animals, totally occlusive in 8, and mural in 1. In contrast, in the hemodiluted group none of the anastomoses presented venous thrombosis, except for the presence of nonadherent blood clots. The clinical analysis of the anastomoses' patency, as evaluated by the empty-full test, showed a significant reduction in rate of venous occlusion in the previously hemodiluted animals as compared with the nonhemodiluted animals 20 min after microsurgical anastomosis. Forty-eight hours after anastomosis, the rate of venous occlusion was 66.7% in the nonhemodiluted group and 33.3% in the hemodiluted group; even though no significant difference could be detected during this time, the patency of anastomoses tended to be greater in the hemodiluted group than that of controls. The rate of spontaneous recanalization after 48 h was identical in both groups (16.6%) in comparison with the rates observed 20 min after the surgical procedure. In summary, moderate isovolemic hemodilution with 3% albumin was effective in reducing the rate of venous microanastomosis occlusion in rats 20 min after the surgical procedure, tending to maintain the anastomoses' patency after 48 h. In addition, 48 h after the microsurgical procedure, the rate of venous thrombosis as evaluated microscopically was significantly lower in the hemodiluted animals as compared with nonhemodiluted control animals. This points out that hemodilution with albumin could be a safe and adequate procedure to prevent thrombus formation at venous microanastomosis.