The Annals of thoracic surgery
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Transesophageal echocardiography (TEE) now is used widely as a monitoring technique during and after cardiac operations. Widespread adoption of the technique has provided a wealth of new information. This review analyzes the influence of TEE on the routine conduct of cardiac operations and on surgical decision making in specific areas. ⋯ Transesophageal echocardiography has a particular role in valve operations, in guiding and assessing the immediate results of mitral valve repair. It also has found application in the grading and operative management of the severely atheromatous aorta, the diagnosis and management of aortic dissection, and other aspects of surgery of the thoracic aorta. In addition, management in specialized areas, such as cardiopulmonary transplantation and the insertion and monitoring of ventricular assist devices, have also been helped by the information provided by TEE.
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Long-term support on the implantable left ventricular assist device (LVAD) produces structural changes in the recipient's heart. To assess the possibility of heart "recovery" we reviewed the records of 19 HeartMate LVAD recipients to determine structural and left ventricular histologic changes during LVAD support. Intraoperative transesophageal echocardiographic studies were performed in the operating room before LVAD insertion, immediately after LVAD insertion, and at explantation and heart transplantation (mean duration of support, 76 +/- 34 days). ⋯ We conclude that implantable LVAD support is associated with immediate changes in ventricular structure. Histologic markers of acute myocyte damage improve, but fibrosis increases. Because the structural changes occur immediately, they do not indicate "recovery" of left ventricular function, but merely changes in loading conditions.
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Comparative Study Clinical Trial Controlled Clinical Trial
Impact of autologous blood predonation on a comprehensive blood conservation program.
Preoperative autologous donation has been shown to be a highly effective measure in reducing homologous blood use in cardiac operations. The aim of our study was to verify the effectiveness of this procedure and to see whether it is compatible with a comprehensive blood conservation program. Three hundred forty-eight patients (group 1) donated an average of 657 +/- 199 mL of blood before open heart operation, whereas 344 patients (group 2) without autologous predonation were used as a control. ⋯ Other blood conservation measures such as the return of mediastinal drainage and use of residual blood of extracorporeal circulation were applied with similar results in both groups. In our experience, preoperative autologous donation was compatible with the application of other blood conservation measures, but acute normovolemic hemodilution was achieved in a lower number of patients. Preoperative autologous donation proved to be a highly effective method for reducing banked blood use and therefore homologous blood exposure during and after cardiac operations.
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Randomized Controlled Trial Comparative Study Clinical Trial
Cerebral blood flow during cardiac operations: comparison of Kety-Schmidt and xenon-133 clearance methods.
This study simultaneously compared the standard Kety-Schmidt and the modified xenon-133 (133Xe) clearance techniques for measuring cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) during cardiac operations. The validity of the CBF method is important because our management of the patient during cardiopulmonary bypass (CPB) is based, in part, on our understanding of the cerebral hemodynamics during CPB. In 20 patients undergoing coronary artery bypass grafting, CBF and CMRO2 were determined by both methods. ⋯ The modified 133Xe technique as typically used during cardiac operations does not appear to measure CBF accurately; this leads to corresponding errors in CMRO2 calculations. Determination of CMRO2 and cerebral autoregulatory function during cardiac operations appears to be more appropriate if based on the more direct Kety-Schmidt technique. Accordingly, our management of CPB with respect to cerebral perfusion as it has been determined by the modified 133Xe clearance method may require reassessment.