RESUMO
Marfan Syndrome is a heritable disorder of connective tissue leading to aortic aneurysms and other cardiovascular complications associated with reduced life expectancy. Marfan patients with thoracic aortic aneurysms (TAAs) or with thoracoabdominal aortic aneurysms (TAAAs) should be treated by means of open surgery, requiring an extensive protocol, including extracorporeal circulation, neuromonitoring and adjunctive modalities to provide organ protection. Then, open surgical repair of TAA(A)s are associated with excellent results. However, in the last time a gradual change to endovascular treatment in Marfan patients is observable. Particularly in patients with an increased surgical risk due to redo sternotomy or thoracotomy, endovascular treatment might be an alternative due to its less invasive approach. Consequently, thoracic endovascular aortic repair comprises a therapeutic alternative in individual situations even in Marfan patients, when the landing zones are safe and appropriate. In cases of failed endovascular therapy, however, conversion to open surgery remains still an option with acceptable results, although the distal and proximal clamping positions change inappropriate with larger extensions due to the aortic stent.
Assuntos
Aneurisma da Aorta Torácica/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular , Procedimentos Endovasculares , Síndrome de Marfan/complicações , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/etiologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/etiologia , Aortografia/métodos , Prótese Vascular , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Pessoa de Meia-Idade , Seleção de Pacientes , Reoperação , Stents , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
The effect of excessive growth hormone (GH) on parathyroid function in rats was evaluated in order to determine whether the GH-induced increase in serum calcium (Ca) may be mediated via stimulation of parathyroid hormone (PTH) secretion. Rats receiving injections of bovine GH 2 mg daily for 4 weeks showed a progressive significant increase in both serum Ca and immunoreactive PTH (iPTH) after the second week. Rats receiving daily injections of rat GH, 0.25 mg daily for 3 weeks, followed by 0.5 mg daily for 3 additional weeks, showed a significant increase in serum iPTH during administration of the higher dose, and also a significantly increased parathyroid gland weight and PTH content. The concomitant increase in serum Ca and iPTH suggest that GH stimulates the parathyroid glands to increase PTH secretion, which in turn causes an increase in serum Ca. The parathyroid response increases with the increase in dose and duration of GH stimulus. The data suggest that the hypercalcemia often observed in acromegaly may be due, at least in part, to GH-induced excessive secretory activity of the parathyroid glands.