The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Mar 1994
Comparative StudyDelayed sternal closure after neonatal cardiac operations.
We retrospectively compared the use of primary elective open sternum coupled with delayed sternal closure with the use of primary sternal closure in neonates after cardiac operations. Primary elective open sternum/delayed sternal closure was selectively used in patients who demonstrated hemodynamic or respiratory deterioration, or both, during an intraoperative trial of sternal closure; otherwise primary sternal closure was used. Primary elective open sternum was used in 55 (61.8%) and primary sternal closure in 34 (38.2%) of the 89 patients studied. ⋯ The overall morbidity and duration of inotropic support were not significantly different between the two groups, although seven (20.6%) of the patients with primary sternal closure did have to undergo delayed sternal reopening for refractory postoperative low cardiac output. There was one superficial wound infection in the primary elective open sternum/delayed sternal closure group. Primary elective open sternum/delayed sternal closure is an effective treatment for postoperative neonatal mediastinal compression for the following reasons: (1) the morbidity is low; (2) the mortality of the critically ill group of neonates in whom primary elective open sternum/delayed sternal closure was used was similar to that of the less critically ill primary sternal closure group; and (3) 20.6% of the primary sternal closure group eventually had to undergo delayed sternal reopening to treat refractory postoperative low cardiac output.
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J. Thorac. Cardiovasc. Surg. · Mar 1994
Prevention of complement-induced pulmonary hypertension and improvement of right ventricular function by selective thromboxane receptor antagonism.
The effect of complement activation on the pulmonary vascular system and on right ventricular function was studied in sheep (n = 12) by injection of cobra venom factor. Animals were instrumented for measurement of pulmonary flow, mean pulmonary artery pressure, right ventricular stroke work, arterial blood gases, and systemic vascular resistance. Blood was sampled from the left atrium and pulmonary artery to measure thromboxane B2, the metabolite of thromboxane A2, by radioimmunoassay. ⋯ A pulmonary vascular thromboxane B2 gradient of approximately 1000 pg/ml was measured at 15 and 30 minutes in both control and treated groups. (p < 0.05) We conclude that after complement activation in this model pulmonary hypertension and decreased oxygen tension are mediated by thromboxane release from the pulmonary vascular bed. This increased afterload causes a stress on the right ventricle as demonstrated by the increased right ventricular stroke work. Selective thromboxane receptor antagonism may be a beneficial therapy for pulmonary hypertension in patients after cardiopulmonary bypass.
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J. Thorac. Cardiovasc. Surg. · Mar 1994
Interactions between preischemic hypothermia and cardioplegic solutions in the neonatal lamb heart.
Hypothermia is believed to improve the tolerance to both ischemia and cardiopulmonary bypass and is commonly used during heart operations, particularly in the neonate. However, hypothermia also causes calcium to accumulate in the myocyte experimentally, and an increase in intracellular calcium during ischemia may worsen the effect of ischemia and impair the postischemic recovery of function. This effect of hypothermia on intracellular calcium has generally not been considered in experiments that attempt to optimize the composition of cardioplegic solutions. ⋯ However, with preischemic cooling, St. Thomas' cardioplegia (group ST-C) resulted in a significantly reduced recovery of both systolic and diastolic function (developed pressure = 81.6% +/- 6.2%, dP/dt = 75.1% +/- 8.4%, left ventricular stiffness constant = 103.7% +/- 2.7%) compared with that for both glucose-potassium cardioplegia (group GK-C: developed pressure = 92.4% +/- 8.7%, dP/dt = 83.7% +/- 6.0%, left ventricular stiffness constant = 100.5% +/- 2.1%) and St. Thomas' cardioplegia without preischemic cooling (group ST-NC) (p < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)