The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 1993
Late results of valve replacement with the Björk-Shiley valve (1973 to 1982)
Cardiac valve replacement with use of only the Björk-Shiley prosthesis was performed in 1253 patients between January 1973 and December 1982. There were 828 patients having aortic valve replacement, 280 patients having mitral valve replacement, and 145 patients having double valve replacement with aortic and mitral valve prostheses. Patient outcome was stratified according to multiple variables, including valve position and valve model (spherical versus convexo-concave discs). ⋯ Overall event-free survival (freedom from death, thromboembolism, anticoagulant-related bleeding, endocarditis, and reoperation) was similar for the three patient groups. Performance of the Björk-Shiley valve as judged by late patient follow-up is similar to other mechanical valves, and modifications in disc design do not appear to have reduced the threat of late valve thrombosis and thromboemboli. Evidence does not support elective explantation of this prosthesis.
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Case ReportsBiventricular repair of hypoplastic right ventricle assisted by pulsatile bidirectional cavopulmonary anastomosis.
The right ventricle in patients with severe outflow obstruction or atresia and a small tricuspid valve often remains too hypoplastic even after optimal palliation to tolerate biventricular repair with closure of the atrial septal defect. In these patients, nonpulsatile cavopulmonary (Glenn) anastomosis has traditionally facilitated biventricular repair. In 1989, Billingsley and associates reported the addition of a bidirectional cavopulmonary anastomosis to the definitive biventricular repair in patients with hypoplastic right ventricle, pulmonary atresia, and intact ventricular septum. ⋯ These complications were controlled with the addition of bidirectional cavopulmonary anastomosis 2 months later. Postoperative hemodynamic or Doppler studies in these patients revealed pulsatile flow in the entire pulmonary artery system, including the artery distal to the Glenn anastomosis. This modification of biventricular repair allows primary closure of the atrial septal defect and provides pulsatile arterial flow in the entire pulmonary artery, even when the right ventricle is significantly hypoplastic.
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Clinical TrialTranexamic acid (Cyklokapron) is not necessary to reduce blood loss after coronary artery bypass operations.
The contribution of fibrinolysis to postoperative bleeding after cardiopulmonary bypass led to routine use of tranexamic acid, a potent antifibrinolytic drug, for a period of time. Two hundred patients undergoing elective coronary artery bypass operations were studied, one group of 100 patients given tranexamic acid (40 mg/kg) (group I) after bypass and one subsequent group of 100 patients (group II) serving as a control group. All patients were treated by the same team, and the groups were comparable in all major clinical parameters. ⋯ Although not statistically significant (p = 0.2), the difference is of concern. Tranexamic acid has a beneficial effect on reducing postoperative bleeding after coronary artery bypass operations. The routine use of the drug is not recommended, however, because its effect is a weak one, and it may be of potential hazard by precipitating thrombosis and eventual myocardial infarction.
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J. Thorac. Cardiovasc. Surg. · Jan 1993
Impaired endothelium-dependent coronary microvascular relaxation after cold potassium cardioplegia and reperfusion.
Myocardial dysfunction after cardiac operations might be influenced by altered myocardial perfusion in the postoperative period. To investigate possible alterations in vascular reactivity, in vitro coronary microvascular responses were examined after ischemic cardioplegia with use of a porcine model of cardiopulmonary bypass. Since myocardial perfusion is primarily regulated by arteries less than 200 microns in diameter, these vascular segments were examined. ⋯ After 1 hour of ischemic cardioplegia without reperfusion, endothelium-dependent relaxation was only slightly affected. Transmission electron microscopy showed minimal endothelial damage after ischemic cardioplegia and reperfusion. These findings have important implications regarding coronary spasm and cardiac dysfunction after cardiac operations.