The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Sep 1995
Complications of extracorporeal life support systems using heparin-bound surfaces. The risk of intracardiac clot formation.
Extracorporeal life support with heparin-coated extracorporeal membrane oxygenation circuits are being used with increased frequency in patients who have cardiogenic shock. We report our experience in 30 patients with cardiogenic shock, looking specifically at the complications associated with this form of life support. Thirty patients with a mean age of 46.5 +/- 16.6 years received extracorporeal life support for a mean of 62.8 +/- 41.1 hours (range 0.5 to 159 hours). ⋯ Nine patients (30%) were discharged home. We conclude that the use of heparin-coated extracorporeal life support without systemic heparinization, especially after protamine has been used to reverse systemic heparinization in patients having postcardiotomy cardiogenic shock, may be dangerous. Extracorporeal life support has introduced new complications unique to itself specifically limb ischemia, oxygenator failure, and pump-head thrombus.
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J. Thorac. Cardiovasc. Surg. · Sep 1995
Comparative Study Clinical Trial Controlled Clinical TrialDilation of the internal mammary artery by external and intraluminal papaverine application.
Three methods for prevention of perioperative spasm of the internal mammary artery were compared in 78 patients undergoing coronary artery bypass grafting. In group 1, internal mammary artery pedicles were divided distally, clamped, and placed under the upper sternum submerged in papaverine solution (1.5 mg/ml). In group 2, as in group 1 but before clamping, 2 ml of heparinized blood with 1.5 mg/ml papaverine added was injected into the vessel lumen. ⋯ Morphometric measurements on the resected distal portion of the dilated internal mammary arteries disclosed less folding of the internal elastic lamina and a larger luminal area in groups 2 and 3 compared with respective findings in group 1 (1.21 mm2 and 1.42 mm2 versus 0.77 mm2; p < 0.02). Mechanical vessel wall injury occurred in 8 of 52 internal mammary arteries treated with intraluminal papaverine. Intraluminal papaverine solution injected once or twice in addition to external papaverine exposure therefore provides a better blood flow rate and distal dilation than mere submersion in papaverine solution, but at a considerable risk of mechanical wall injury.
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J. Thorac. Cardiovasc. Surg. · Sep 1995
Protection against injury during ischemia and reperfusion by acadesine derivatives GP-1-468 and GP-1-668. Studies in the transplanted rat heart.
Acadesine (AICAr: 5-amino-4-imidazole carboxamide riboside) has been shown to afford sustained protection against injury during ischemia and reperfusion. The present studies used the heterotopically transplanted rat heart to assess the protective properties of two new acadesine analogs: GP-1-468 and GP-1-668. ⋯ Both GP-1-468 and GP-1-668 increase the rate and extent of early postischemic recovery, and this protection is sustained for at least 24 hours. These beneficial actions were associated with an increase of the tissue content of adenosine during ischemia, but they appeared to be independent of the status of the high-energy metabolism.
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J. Thorac. Cardiovasc. Surg. · Sep 1995
Tissue oxygenation with graded dissolved oxygen delivery during cardiopulmonary bypass.
Intravascular perfluorochemical emulsions together with a high oxygen tension may increase the delivery of dissolved oxygen to useful levels. The hypothesis of this study is that increasing the dissolved oxygen content of blood with incremental doses of a perfluorochemical emulsion improves tissue oxygenation during cardiopulmonary bypass in a dose-related fashion. ⋯ Graded increases in mixed venous oxygen tension during cardiopulmonary bypass were observed in response to graded increases in the dissolved oxygen delivery. These data suggest that enhancing oxygenation with perfluorochemical-dissolved oxygen is an effective temporary substitute for the use of hemoglobin-bound oxygen during cardiopulmonary bypass. Perfluorochemical-dissolved oxygen may be particularly beneficial in the setting of multiple hypoxic stresses.
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J. Thorac. Cardiovasc. Surg. · Aug 1995
Intermittent aortic crossclamping prevents cumulative adenosine triphosphate depletion, ventricular fibrillation, and dysfunction (stunning): is it preconditioning?
This study was designed to determine whether intermittent warm aortic crossclamping induces cumulative myocardial stunning or if the myocardium becomes preconditioned after the first episode of ischemia in canine models in vivo. The role of adenosine triphosphate catabolism and subsequent release of purines on reperfusion-mediated postischemic ventricular dysfunction and arrhythmias was assessed with the use of selective inhibitors of nucleoside transport, p-nitrobenzylthioinosine (NBMPR), and a specific adenosine deaminase inhibitor, erythro-9-[2-hydroxy-3-nonyl] adenine (EHNA). Thirty-two anesthetized dogs were instrumented to monitor left ventricular contractility, off bypass, by sonomicrometry. ⋯ Unlike sustained ischemia, intermittent ischemia and reperfusion preserved myocardial adenosine triphosphate, limited purine release, and prevented ventricular fibrillation and cumulative stunning. These results suggest that intermittent ischemia and reperfusion augmented the endogenous protective mechanism or mechanisms of "preconditioning." Nucleoside trapping improved functional recovery after sustained or repetitive ischemia. It is concluded that adenosine triphosphate preservation or blockade of nucleoside transport may play an important role in the activation of endogenous myocardial protective mechanisms that "precondition" against subsequent ischemic stress.