Deleterious effects of cardiopulmonary bypass on early graft function after single lung allotransplantation: evaluation of a heparin-coated bypass circuit.

Clinical lung transplantation may necessitate the use of cardiopulmonary bypass during the procedure, resulting in increased morbidity with more severe early graft dysfunction and increased blood loss. A heparin surface-coated cardiopulmonary bypass circuit is now available with improved biocompatibility and reduced systemic heparin requirements and may offer advantages compared with standard uncoated cardiopulmonary bypass circuits. This study investigates in a canine model of single-lung allotransplantation whether cardiopulmonary bypass adversely affects early graft function and whether a heparin-coated cardiopulmonary bypass circuit with reduced systemic heparin dosage improves results compared with standard uncoated cardiopulmonary bypass systems. Fifteen dogs underwent left single-lung allotransplantation with occlusion of the contralateral pulmonary artery and bronchus 1 hour after reperfusion. In one group, five animals underwent the procedure without cardiopulmonary bypass. In the group with uncoated circuits, five animals underwent the procedure with the use of standard uncoated cardiopulmonary bypass circuits with full systemic heparin dosage. In the group with heparin-coated circuits, five animals underwent the procedure with the use of heparin-coated cardiopulmonary bypass circuits and reduced systemic heparin dosage. Early graft function was evaluated by arterial oxygenation, pulmonary mechanics, lung water measurements, and histologic analysis. Hemodynamics and postoperative blood loss were also measured. Two hours after reperfusion, partial pressure of oxygen in arterial blood on an inspired oxygen fraction = 1.0 was significantly greater (p < 0.001) in the group without cardiopulmonary bypass (467 +/- 58 mm Hg) than in the group with uncoated circuits (114 +/- 90 mm Hg) and the group with heparin-coated circuits (193 +/- 105 mm Hg), with no significant difference between the groups undergoing bypass procedures. Lung compliance decreased and lung water increased in all transplanted lungs without significant differences between groups. Histologic analysis did not differentiate between the groups. After reperfusion, cardiac index and mean arterial pressure were significantly reduced in the groups with uncoated circuits and with heparin-coated circuits compared with the group that did not undergo cardiopulmonary bypass (p < 0.001). Postoperative blood loss was significantly less (p < 0.002) in the group that did not undergo cardiopulmonary bypass (90 ml +/- 38 ml) compared with both the group with uncoated circuits (750 +/- 15 ml) and the group with heparin-coated circuits (690 +/- 387 ml), with no significant difference between the groups that underwent bypass. The use of cardiopulmonary bypass with systemic heparinization is detrimental to early graft function in this canine model of left single-lung allotransplantation.(ABSTRACT TRUNCATED AT 400 WORDS)

Incomplete ventricular septal tear after blunt chest trauma: medical management with serial echocardiographic follow-up.

Incomplete ventricular septal tears are uncommon or probably underreported cardiac lesions caused by blunt chest trauma. This report describes two cases of incomplete ventricular septal tears that were not suspected clinically. Transthoracic and transesophageal echocardiography provided the diagnostic information in both of these cases. Despite associated valvular lesions, the patients' stable in-hospital course lead to the decision to treat them medically with no specific treatment to the incomplete ventricular septal tears. Accordingly, these two cases were observed for a mean period of 1.5 years with serial echocardiographic studies to track the natural history of these lesions. During the follow-up period, both of these cases did not manifest any changes in the extent of ventricular septal tear, septal structure, or any left-to-right shunting through the tear. There were no significant changes in left ventricular size, shape, or systolic function. Thus echocardiographic imaging proved to be useful both in initial diagnosis and follow-up.

Early diagnosis and follow-up by echocardiography of acquired cor triatriatum after orthotopic heart transplantation.

Acquired cor triatriatum in a heart transplant recipient, secondary to a prominent left atrial suture line and torsion of the atria, was diagnosed immediately after cardiopulmonary bypass by transesophageal echocardiography. The patient was followed with serial echocardiograms and right heart catheterizations, showing resolution of the obstruction.