Interactive cardiovascular and thoracic surgery
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Interact Cardiovasc Thorac Surg · Aug 2009
Computational fluid dynamics simulation of transcatheter aortic valve degeneration.
Studied under clinical trials, transcatheter aortic valves (TAV) have demonstrated good short-term feasibility and results in high-risk surgical patients with severe aortic stenosis. However, their long-term safety and durability are unknown. The objective of this study is to evaluate hemodynamic changes within TAV created by bioprosthetic leaflet degeneration. ⋯ CFD simulations in this study provide the first of its kind data quantifying hemodynamics within stenosed TAV. Stenosis leads to significant forces of TAV during systole; however, diastolic forces predominate even with significant stenosis. Substantial changes in peak shear stress occur with TAV degeneration. As the first implanted TAV begin to stenose, the authors recommend watchful examination for device failure.
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Interact Cardiovasc Thorac Surg · Aug 2009
Left ventricular performance in aortic valve replacement.
We analyzed the mid-term left ventricular (LV) performance after aortic valve replacement (AVR). We measured LV contractility (end-systolic elastance: Ees), afterload (effective arterial elastance: Ea) and efficiency (ventriculoarterial coupling: Ea/Ees; ratio of stroke work and pressure-volume area: SW/PVA) based on transthoracic echocardiography data obtained before, after and approximately 1 year after isolated AVR in 263 patients with aortic stenosis (AS group; n=116), aortic regurgitation (AR group; n=93) or aortic stenosis and regurgitation (ASR group; n=54). The LV volume was calculated by the Teichholz M-mode method. ⋯ Contrasting effects of AVR on LV contractility and afterload between AS and AR were clearly demonstrated. The mid-term LV contractility and efficiency after AVR were excellent and satisfactory. However, LV efficiency worsened early after AVR in AR patients.
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Interact Cardiovasc Thorac Surg · Aug 2009
Aprotinin reduces the antiplatelet effect of clopidogrel.
Aprotinin reduces bleeding and transfusion rates in patients undergoing coronary surgery while on clopidogrel. However, safety studies have indicated that aprotinin may have a possible adverse effect related to an increased incidence of thromboembolic events. We therefore studied the adenosinediphosphate (ADP) mediated platelet aggregation before and after administration of aprotinin in patients on clopidogrel. ⋯ Clopidogrel non-responders with >90% aggregation (n=4) had a median aggregation of 94.5% (91.5/97.5) vs. 82% (73/87, P<0.01) in the responders (n=11). The median increase in platelet aggregation after aprotinin was 8% (5/20) in the responders vs. 0% (-5.25/3, P<0.01) in the non-responders. Aprotinin increased ADP induced platelet aggregation from 84 to 94% in patients on clopidogrel, which corresponds to a median decrease in relative platelet inhibition of >50%.
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Interact Cardiovasc Thorac Surg · Aug 2009
Case ReportsIntra aortic balloon pump insertion through left axillary artery in patients with severe peripheral arterial disease.
Intra aortic balloon pump (IABP) is the mechanical assist device most frequently used in cardiac surgery. Recent demonstration of better outcome following preoperative IABP insertion in high-risk patients has further extended its indication. However, due to an increasing complexity of patients currently referred for cardiac surgery, several patients with potential indication for preoperative and/or postoperative IABP present severe peripheral vascular disease which usually contraindicates IABP insertion. Here we present an alternative technique for IABP insertion in patients with severe peripheral vessel disease.
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Interact Cardiovasc Thorac Surg · Aug 2009
Case ReportsTriple heart valve surgery through a right antero-lateral minithoracotomy.
Triple valve surgery remains a complex intervention, with prolonged cardiopulmonary bypass (CPB) and cross-clamp times. A median sternotomy is the standard approach in the surgical treatment of multiple valve disease. In this report, we attempt to describe our approach for the correction of the triple heart valve disease through a right antero-lateral minithoracotomy, because avoiding sternotomy can bring less wound infections, faster recovery and a shorter hospital stay. The right minithoracotomy in the 3rd intercostal space was applied in two patients and a feasibility of either repair or replacement with a good field exposure to access the aortic, mitral and tricuspid valves without any particular difficulties was verified.