The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Replacement of the thoracic aorta with collagen-impregnated woven Dacron grafts. Early results.
We used the collagen-impregnated woven double-velour Dacron graft in 120 patients undergoing 122 aortic reconstructions. Seventy-nine aortic root, ascending, or arch replacements were performed during cardiopulmonary bypass with or without circulatory arrest; 53 of the 79 were for acute aortic dissection. In addition, three infants and one child underwent repair of truncus arteriosus. ⋯ Its handling and suturing characteristics are excellent, and the graft is completely impervious in its originally manufactured state. Needle holes self-seal rapidly. Medium-term follow-up by clinical, angiographic, computed tomographic, and magnetic resonance imaging techniques showed no late graft complications--specifically, no dilatation or thrombus formation.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Influence of hydrogen ion concentration versus carbon dioxide tension on pulmonary vascular resistance after cardiac operation.
Disturbances of respiratory acid-base status are common in patients supported with mechanical ventilation of the lungs after cardiac operations. This study was conducted with two protocols. The purpose was to determine whether respiratory acid-base status influences pulmonary vascular resistance in adults after cardiac operations and whether the influence is mediated by hydrogen ion concentration or carbon dioxide tension. ⋯ The results of the second protocol showed that changes in pulmonary vascular resistance index were parallel to changes in hydrogen ion concentration as arterial carbon dioxide tension was held constant (p < 0.05). These data demonstrate that respiratory acid-base status is an important determinant of pulmonary vascular resistance in the adult after cardiac operations. Furthermore, these data suggest the effect is mediated by hydrogen ion concentration, not carbon dioxide tension.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Comparative StudyComplement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits.
The degree of complement activation during cardiopulmonary bypass is considered a valuable parameter of biocompatibility of the extracorporeal circuit. In an in vitro setting with a heart-lung machine primed with fresh whole blood and saline solution, the C3 activation products C3b, iC3b, and C3c and the terminal complement complex were measured in double-antibody enzyme immunosorbent assays. No differences were found between seven sets treated with Duraflo II heparin coating and seven uncoated sets after 2 hours of circulation. ⋯ In a supplementary series, the sterilization process did not influence the results. Although Duraflo II heparin coating is considered highly effective in preventing coagulation, it did not prevent complement activation in the present in vitro study. We hypothesize that the mode by which the heparin molecule is bound to the surface may be essential to obtain effects on both coagulation and complement system.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Pulmonary vascular disease and operative indications in complete atrioventricular canal defect in early infancy.
Pulmonary vascular disease was morphometrically analyzed in 67 patients (mean age, 19 months) with isolated complete atrioventricular canal defect. Complete obstruction of the small pulmonary arterial lumen resulting from acute fibrous proliferation and atrophy of the peripheral arterial media, which were considered absolute operative contraindications, were characteristic in six patients with Down's syndrome. Morphometric analysis of medial thickness revealed that thinning of the media of the small pulmonary arteries is generally observed at around 6 months of age in patients with complete atrioventricular canal defect and that the media in patients who have complete atrioventricular canal defect and Down's syndrome was thinner than that in such patients without Down's syndrome. ⋯ Excluding patients with absolute operative contraindications, the scores of the index of pulmonary vascular disease in operative survivors were below 2.0 and death occurred when scores were more than 2.2. The pulmonary vascular resistances measured in room air and by the oxygen inhalation and tolazoline tests in patients with operative contraindications were more than 7.3, 3.8, and 6.6 units.m2, respectively. We thus conclude that lung biopsy should be undertaken for patients in whom pulmonary vascular resistance is beyond these values to determine the appropriateness of surgical intervention.
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J. Thorac. Cardiovasc. Surg. · Sep 1993
Surgical repair of complete atrioventricular canal defects in infancy. Twenty-year trends.
Case histories of 301 patients with complete atrioventricular canal defect presenting to our institution in infancy between January 1972 and January 1992 were reviewed with the purpose of identifying the factors responsible for the observed improvement in perioperative mortality over this time period. A retrospective analysis of hospital records examined 46 patient-related, morphologic, procedure-related, and postoperative variables for associations with perioperative death and reoperation. Operative mortality decreased significantly over the period of the study from 25% before 1976 to 3% after 1987 (p < 0.0001). ⋯ Experience-related improvements in technical precision achieved over time best account for the reduction in the rate of reoperation for most types of residual lesions and also for the reduction in mortality. The only residual lesion that has not been essentially completely eliminated is left atrioventricular valve regurgitation, with reoperation for this lesion having been reduced in recent years, but not eliminated. Improved understanding of the structural and functional variability of the atrioventricular valve in this lesion may be necessary before postoperative dysfunction of this valve can be completely eliminated.