Gene expression of endothelin-1 and endothelin receptor a on monocrotaline-induced pulmonary hypertension in rats after bosentan treatment.

BACKGROUND AND OBJECTIVES: Endothelin (ET)-1, a potent endothelium-derived vasoconstrictor peptide, has a potential pathophysiologic role in pulmonary hypertension. Bosentan, a dual ET receptor (ET(A)/ET(B)) antagonist, is efficacious in treatment of pulmonary hypertension. The objectives of this study were to investigate the expression of ET-1 and ET receptor A (ERA) genes and to evaluate the effect of bosentan in monocrotaline (MCT)-induced pulmonary hypertension. MATERIALS AND METHODS: Four-week-old male Sprague-Dawley rats were treated as follows: control (n=36), subcutaneous (sc) injection of saline; MCT (n=36), sc injection of MCT (60 mg/kg); and bosentan (n=36), sc injection of MCT (60 mg/kg) plus 25 mg/kg/day bosentan orally. RESULTS: Serum ET-1 concentrations in the MCT group were higher than the control group on day 28 and 42. Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan group on day 28 and 42. In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on day 14, 28 and 42. The levels of ET-1 and ERA gene expression were significantly increased in the MCT group compared with control group on day 5, and bosentan decreased the expression of ET-1 on day 5. CONCLUSION: ET-1 contributes to the progression of cardiopulmonary pathology in rats with MCT-induced pulmonary hypertension. Administration of bosentan reduced ET-1 gene expression in MCT-induced pulmonary hypertension in rats.

Prenatal double aortic arch presenting with a right aortic arch and an anomalous artery arising from the ascending aorta.

Double aortic arch is a rare anomaly of the aortic arch and this may cause tracheal damage by compressing the trachea during the first year of life. We report here on three fetal cases of double aortic arch and their outcomes. These malformations presented as an isolated right aortic arch or as a typical vascular ring form on the prenatal echocardiography that was obtained between 22 and 24 weeks gestation. In two of the three patients, the major intracardiac anomaly was a ventricular septal defect, and this was associated with the aortic malformation. A more detailed evaluation of the branching pattern of the aorta, and particularly whether the aorta gives off a left-sided limb of the double arch, could suggest the diagnosis of a double aortic arch in utero. Two patients underwent successful surgical correction and they showed good clinical outcomes. Fetal double aortic arch can be prenatally suspected after performing fetal echocardiography for those fetuses that show a right side aortic arch, and this can help to avoid delaying the postnatal management of this rare anomaly.

Somatostatin for postoperative chylothorax after surgery for children with congenital heart disease.

Chylothorax is a rare but serious postoperative condition with a high rate of morbidity that may lead to death of children with congenital heart disease. Here we reviewed nine consecutive cases with chylothorax in infants and children following cardiac surgery from March 2002 to February 2003. Somatostatin was added to conservative treatment protocol to increase effectiveness of therapy in all cases. The duration of somatostatin therapy varied from 7 to 32 days. All cases of chylothorax were successfully treated with intravenous infusion of somatostatin as an adjunctive treatment. Even though two cases showed rebound phenomena, we avoided any surgical procedure in the nine patients who treated with conservative management combined with somatostatin. No significant side effects of somatostatin were observed. It seems that somatostatin is effective, noninvasive and safe therapeutic modality. It can be used as an adjunctive treatment to conservative management to control postoperative chylothorax in children with congenital heart disease.

Successful repair of critical tricuspid regurgitation secondary to ruptured papillary muscle in a newborn.

We report a rare case of an isolated critical tricuspid regurgitation due to rupture of a papillary muscle. This patient presented with a cyanosis immediately after birth. Despite mechanical ventilation and medical management to decrease the pulmonary vascular resistance, the low cardiac output persisted, along with the cyanosis. Repair of the tricuspid valve was performed, using an artificial tendinous cord, on the 4th day of life. The short-term result of the surgery is satisfactory, but the patient requires long-term follow-up.