The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Jun 2002
Increased endothelin-1 production in diabetic patients after cardioplegic arrest and reperfusion impairs coronary vascular reactivity: reversal by means of endothelin antagonism.
Evidence has accrued to suggest that diabetic patients face an increased risk of ischemic events and low output syndrome and might mount an inordinate response to ischemia and reperfusion. Because hyperglycemia is a potent stimulus for endothelin-1 production, we hypothesized that increased production, action, or both of endothelin-1 in diabetes might represent an important mediator of endothelial dysfunction in patients with that disease. To this aim, we compared the effects of cardioplegic arrest and reperfusion on coronary sinus effluent endothelin-1 levels and atrial arteriolar vascular responses in diabetic and case-matched nondiabetic patients undergoing coronary artery bypass grafting. ⋯ We determined the following: (1) the coronary effluent release of endothelin-1 is higher in diabetic than in nondiabetic patients after cardiopulmonary bypass and reperfusion; (2) diabetic coronary microvessels respond to bypass and reperfusion with greater endothelin-1-mediated vasoconstriction and diminished nitric oxide-mediated vasodilatation; and (3) these effects are attenuated by endothelin antagonism. Endothelin-1 might be an important mediator of ischemia-reperfusion injury in patients with diabetes. Furthermore, use of endothelin receptor antagonists might be a novel strategy for improving the resistance of the diabetic heart to cardioplegic arrest and reperfusion.
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J. Thorac. Cardiovasc. Surg. · Jun 2002
Ischemic mitral regurgitation: intraventricular papillary muscle imbrication without mitral ring during left ventricular restoration.
Functional mitral regurgitation in ischemic cardiomyopathy carries a poor prognosis, and its surgical management remains problematic and controversial. The aim of this study was to report the results of our surgical approach to patients who have had myocardial infarctions and have ventricular dilatation, mitral regurgitation, reduced pump function, pulmonary hypertension and coronary artery disease. This surgical approach consists of endoventricular mitral repair without prosthetic ring, ventricular reconstruction with or without patch, and coronary artery bypass grafting. ⋯ Our aggressive, combined surgical approach is aimed at correcting the three components of ischemic cardiomyopathy: relieving ischemia, reducing left ventricular wall tension by decreasing left ventricular volumes, and reducing volume overload and pulmonary hypertension by repairing the mitral valve. Despite a relatively high perioperative mortality rate, surviving patients benefitted from the operation, with improved clinical functional class and thus quality of life.
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J. Thorac. Cardiovasc. Surg. · Jun 2002
Cardiopulmonary bypass reduction of bronchial blood flow: a potential mechanism for lung injury in a neonatal pig model.
During total cardiopulmonary bypass, blood flow to the lungs is limited to flow through the bronchial arteries. We tested the hypothesis that bronchial blood flow during cardiopulmonary bypass is insufficient to prevent ischemia of the lung and that perfusion of the pulmonary arteries with oxygenated blood during bypass would reduce lung injury. ⋯ Cardiopulmonary bypass caused a reduction in bronchial arterial blood flow, which was associated with injury of the lung. Controlled pulmonary perfusion reduced injury to the lung during bypass. The inflammatory response, as evidenced by bronchoalveolar lavage fluid, may be caused by ischemia.
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J. Thorac. Cardiovasc. Surg. · Jun 2002
Randomized Controlled Trial Clinical TrialHemostatic effects of tranexamic acid in elective thoracic aortic surgery: a prospective, randomized, double-blind, placebo-controlled study.
We studied the hemostatic effects of tranexamic acid in patients undergoing elective surgery involving the thoracic aorta. ⋯ In this initial series of patients undergoing thoracic aortic surgery, tranexamic acid appeared effective in reducing perioperative bleeding, with a significant reduction in the need for allogeneic transfusions and without any increased risk of thrombotic complications.
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J. Thorac. Cardiovasc. Surg. · Jun 2002
Midterm follow-up of penetrating ulcer and intramural hematoma of the aorta.
Most studies on variant forms of aortic dissection--penetrating ulcer and intramural hematoma--have focused on the initial presenting episode, with scant follow-up. This investigation provides midterm follow-up of penetrating ulcer and intramural hematoma to determine whether the aorta shows healing according to radiography, goes on to dilate, or tends to rupture during later follow-up. ⋯ Intramural hematoma and penetrating ulcer are lesions associated with advanced age. Women predominate. Penetrating ulcer and intramural hematoma rupture both early and late. Radiographically documented worsening, improvement, or frank dissection may occur with time. Aortic growth does occur (0.2 cm per year for penetrating ulcer and 0.4 cm per year for intramural hematoma). Vascular ischemic complications do not occur. Because of the high early rupture rate, the frequency of radiographic worsening, and the documented occurrence of late rupture, we now recommend surgical replacement of the aorta for these virulent vascular lesions as long as the patient's comorbidities do not preclude surgical intervention.