The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Feb 1996
One-stage repair of interrupted aortic arch, ventricular septal defect, and subaortic obstruction in the neonate: a novel approach.
One-stage repair of interrupted aortic arch, ventricular septal defect, and severe subaortic stenosis represents a surgical challenge. Techniques that use extracardiac conduits to bypass the subaortic area or involve transaortic or transatrial resection of the conal septum have shown limitations and have failed to reduce the high mortality rate associated with subaortic obstruction. ⋯ Relief of severe subaortic stenosis during one-stage neonatal repair of aortic arch interruption and ventricular septal defect can be accomplished successfully without resection of the conal septum.
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J. Thorac. Cardiovasc. Surg. · Feb 1996
Clinical TrialHomograft replacement of the mitral valve. Graft selection, technique of implantation, and results in forty-three patients.
Because of experience gained in reconstructive mitral valve surgery, we have reevaluated the implantation of cryopreserved homografts in the mitral position. Forty-three patients, aged 11 to 69 years (mean 34 years), underwent mitral valve replacement with cryopreserved mitral homografts. The indications for the procedure were acute endocarditis (n = 14), rheumatic stenosis (n = 26), systemic lupus endocarditis (n = 2), and marasmic endocarditis (n = 1). All homografts were obtained from hearts explanted in the course of transplantation and were cryopreserved at -160 degrees C in 10% dimethyl sulfoxide solution without antibiotics. Appropriate sizing was based on morphologic study of the homografts and preoperative echocardiographic assessment of the recipient valve. In 82 homografts analyzed, the height of the anterior leaflet was 25 +/- 3 mm and the distance from the anulus to the apex of the anterior papillary muscle was 21 +/- 3 mm. The morphologic features of the papillary muscles were classified according to four types of increasing complexity. Nine valves with complex (type IV) papillary muscle abnormalities were discarded. Echocardiographic measurements of the valve were matched with those of the homograft identification cards and a slightly larger homograft was selected (measurements + 3 mm). Partial homograft replacement was done in case of a localized lesion (abscess or calcification) (n = 21). Total homograft replacement was undertaken in the presence of diffuse lesions (n = 22). Two hospital deaths occurred as a result of poor cardiac output. One patient required reoperation on the tenth postoperative day after a dehiscence on the valvular suture line. After a mean follow-up of 14 months, there has been one late death caused by a bronchial neoplasm and one reoperation for residual stenosis (partial replacement). The remaining patients were in either New York Heart Association class I (n = 25) or II (n = 13). Thirty-three patients were in sinus rhythm. Follow-up echocardiography has revealed no mitral regurgitation (n = 20), minimal mitral regurgitation (n = 13), and mild mitral regurgitation (n = 5). Surface valve area has been calculated at 2.5 +/- 0.4 cm2 in partial homograft reconstruction and 2.7 +/- 0.3 cm2 in total homograft replacement, with a transvalvular gradient of 3 +/- 4 mm Hg. ⋯ In a selected group of patients, the use of mitral homografts significantly extended the present limitations of reparative surgery of the mitral valve.
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J. Thorac. Cardiovasc. Surg. · Jan 1996
pH-stat cooling improves cerebral metabolic recovery after circulatory arrest in a piglet model of aortopulmonary collaterals.
Cardiopulmonary bypass with deep hypothermic circulatory arrest increases the risk of neurologic injury in patients with aortopulmonary collaterals. Experimental studies have demonstrated that such collaterals decrease the rate of cerebral cooling before arrest and cerebral metabolic recovery after circulatory arrest. Use of pH-stat blood gas management has been shown to increase cerebral blood flow during cooling. ⋯ The cerebral metabolic rate of oxygen consumption (a marker for neurologic function) was significantly lower after circulatory arrest in the shunt animals cooled with alpha-stat blood gas management than in the control animals subjected to alpha-stat management (1.2 +/- 0.2 vs 2.3 +/- 0.2 ml oxygen per 100 gm/min, p < 0.05). By contrast, there was no difference between the pH-stat shunt animals and either control group (2.1 +/- 0.2 vs 2.3 +/- 0.2 [alpha-stat] and 2.0 +/- 0.3 [pH-stat] ml oxygen per 100 gm/min, p = not significant). pH-Stat cooling protected the brain from shunt-related injury. When circulatory arrest is used in the presence of aortopulmonary collaterals, the use of pH-stat blood gas management during cooling results in better cerebral protection than alpha-stat blood gas management.
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J. Thorac. Cardiovasc. Surg. · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialSurface-bound heparin fails to reduce thrombin formation during clinical cardiopulmonary bypass.
The hypothesis that heparin-coated perfusion circuits reduce thrombin formation and activity; fibrinolysis; and platelet, complement, and neutrophil activation was tested in 20 consecutive, randomized adults who had cardiopulmonary bypass. Twenty identical perfusion systems were used; in 10, all blood-contacting surfaces were coated with partially degraded heparin (Carmeda process; Medtronic Cardiopulmonary, Anaheim, Calif.). All patients received a 300 U/kg dose of heparin. ⋯ Radioimmunoassay showed a significant increase in surface-adsorbed antithrombin on coated circuits but no significant differences between groups for other proteins. We conclude that heparin-coated circuits used with standard doses of systemic heparin reduce platelet adhesion and improve platelet function but do not produce a meaningful anticoagulant effect during clinical cardiopulmonary bypass. The data do not support the practice of reducing systemic heparin doses during cardiac operations with heparin-coated extracorporeal perfusion circuitry.