Partial versus Complete Sternotomy for Aortic Valve Replacement-Multicenter Study.

BACKGROUND: The benefits of minimally invasive techniques in cardiac surgery remain poorly defined. We evaluated the short- and mid-term outcomes after surgical aortic valve replacement through partial upper versus complete median sternotomy (MS) in a large, German multicenter cohort. METHODS: A total of 2,929 patients underwent isolated surgical aortic valve replacement via partial upper sternotomy (PUS, n = 1,764) or MS (n = 1,165) at nine participating heart centers between 2016 and 2020. After propensity-score matching, 1,990 patients were eligible for analysis. The primary end point was major adverse cardiac and cerebrovascular events (MACCE), a composite of death, myocardial infarction, and stroke at 30 days and in follow-up, up to 5 years. Secondary end points were acute kidney injury, length of hospital stay, transfusions, deep sternal wound infection, Dressler's syndrome, rehospitalization, and conversion to sternotomy. RESULTS: Unadjusted MACCE rates were significantly lower in the PUS group both at 30 days (p = 0.02) and in 5-year follow-up (p = 0.01). However, after propensity-score matching, differences between the groups were no more statistically significant: MACCE rates were 3.9% (PUS) versus 5.4% (MS, p = 0.14) at 30 days, and 9.9 versus 11.3% in 5-year follow-up (p = 0.36). In the minimally invasive group, length of intensive care unit (ICU) stay was shorter (p = 0.03), Dressler's syndrome occurred less frequently (p = 0.006), and the rate of rehospitalization was reduced significantly (p < 0.001). There were 3.8% conversions to full sternotomy. CONCLUSION: In a large, German multicenter cohort, MACCE rates were comparable in surgical aortic valve replacement through partial upper and complete sternotomies. Shorter ICU stay and lower rates of Dressler's syndrome and rehospitalization were in favor of the partial sternotomy group.

Is 300 Seconds ACT Safe and Efficient during MiECC Procedures?

INTRODUCTION: The recommended minimum activated clotting time (ACT) level for cardiopulmonary bypass (CPB) of 480 seconds originated from investigations with bubble oxygenators and uncoated extracorporeal circulation (ECC) systems. Modern minimal invasive ECC (MiECC) systems are completely closed circuits containing a membrane oxygenator and a tip-to-tip surface coating. We hypothesized that surface coating and the "closed-loop" design allow the MiECC to safely run with lower ACT levels and that an ACT level of 300 seconds can be safely applied without thromboembolic complications. The aim of this study was to investigate the potential risks during application of reduced heparin levels in patients undergoing coronary surgery. METHODS: In this study, 68 patients undergoing coronary artery bypass grafting with MiECC were randomized to either the study group with an ACT target of 300 seconds or the control group with an ACT of 450 seconds. All other factors of MiECC remained unchanged. RESULTS: The study group received significantly less heparin and protamine (heparin [international units] median [min-max], Red_AC: 32,800 [23,000-51,500] vs. Full_AC: 50,000 [35,000-65,000] p < 0.001; protamine [international units], Red_AC: 18,000 [10,000-35,000] vs. Full_AC: 30,000 [20,000-45,000] p < 0.001). The ACT in the study group was significantly lower at the start of MiECC (mean ± standard deviation: study group 400 ± 112 vs. control group 633 ± 177; p < 0.0001). Before termination of CPB the ACT levels were: study group 344 ± 60 versus control group 506 ± 80. In both groups, the values of the endogenous thrombin potential (ETP) decreased simultaneously. None of the study participants experienced thromboembolic complications. CONCLUSION: Since no evidence of increased thrombin formation (ETP) was found from a laboratory standpoint, we concluded that the use of MiECC with a reduced anticoagulation strategy seems possible. This alternative anticoagulation strategy leads to significant reduction in dosages of both heparin and protamine. We can confidently move forward with investigating this anticoagulation concept. However, to establish clinical safety of ACT below 300 seconds, we need larger clinical studies.

Shed-blood-separation and cell-saver: an integral Part of MiECC? Shed-blood-separation and its influence on the perioperative inflammatory response during coronary revascularization with minimal invasive extracorporeal circulation systems - a randomized controlled trial.

OBJECTIVE: The postoperative systemic inflammatory response after cardiopulmonary bypass (CPB) is still an undesirable side-effect after cardiac surgery. It is most likely caused by blood contact with foreign surfaces and by the surgical trauma itself. However, the recirculation of activated shed mediastinal blood is another main cause of blood cell activation and cytokine release. Minimal invasive extracorporeal circulation (MiECC) comprises a completely closed circuit, coated surfaces and the separation of suction blood. We hypothesized that MiECC, with separated cell saved blood, would induce less of a systemic inflammatory response than MiECC with no cell-saver. The aim of this study was, therefore, to investigate the impact of cell washing shed blood from the operating field versus direct return to the ECC on the biomarkers for systemic inflammation. MATERIAL AND METHODS: In the study, patients with MiECC and cell-saver were compared with the control group, patients with MiECC and direct re-transfusion of the drawn blood shed from the surgical field. RESULTS: High amounts of TNF-α (+ 120% compared to serum blood) were found in the shed blood itself, but a significant reduction was demonstrated with the use of a cell-saver (TNF-α ng/l post-ECC 10 min: 9.5±3.5 vs. 19.7±14.5, p<0.0001). The values for procalcitonin were not significantly increased in the control group (6h: 1.07±3.4 vs. 2.15±9.55, p=0.19) and lower for C-reactive protein (CRP) (24h: 147.1±64.0 vs.134.4±52.4 p=0.28). CONCLUSION: The use of a cell-saver and the processing of shed blood as an integral part of MiECC significantly reduces the systemic cytokine load. We, therefore, recommend the integration of cell-saving devices in MiECC to reduce the perioperative inflammatory response.

Interhospital air transport of a blind patient on extracorporeal life support with consecutive and successful left ventricular assist device implantation.

The use of extracorporeal life support systems (ECLS) in patients with postcardiotomy low cardiac output syndrome (LCO) as a bridge to recovery and bridge to implantation of ventricular assist device (VAD) is common nowadays. A 59-year-old patient with acute myocardial infarction received a percutaneous transluminal angioplasty and stenting of the circumflex artery. During catheterization of the left coronary artery (LAD), the patient showed ventricular fibrillation and required defibrillation and cardiopulmonary resuscitation. After implantation of an intra-aortic balloon pump, the patient immediately was transmitted to the operating room. He received emergency coronary artery bypass grafting in a beating heart technique using pump-assisted minimal extracorporeal circulation circuit (MECC). Two bypass grafts were performed to the LAD and the right posterior descending artery. Despite initial successful weaning off cardiopulmonary bypass with high-dose inotropic support, the patient presented postcardiotomy LCO and an ECLS was implanted. The primary setup of the heparin-coated MECC system was modified and used postoperatively. As a result of the absence of an in-house VAD program, the patient was switched to a transportable ECLS the next day and was transferred by helicopter to the nearest VAD center where the patient received a successful insertion of a left VAD 3 days later.

Transcatheter mitral valve implantation versus conventional redo surgery for degenerated mitral valve prostheses and rings in a multicenter registry.

OBJECTIVES: Degeneration of mitral prostheses/rings may be treated by redo surgery, and, recently, by transcatheter valve-in-valve/ring implantation. This multicenter registry presents results of transcatheter valve-in-valve and repeat surgery for prostheses/rings degeneration. METHODS: Data provided by 10 German heart centers underwent propensity score-matched retrospective analysis. The primary endpoint was 30-day/midterm mortality. Perioperative outcome was assessed according to the Mitral Valve Academic Research Consortium criteria. Further, the influence of moderate or greater tricuspid regurgitation (TR) on 30-day/midterm mortality was analyzed. RESULTS: Between 2014 and 2019, 273 patients (79 transcatheter mitral valve-in-valve [TM-ViV] and 194 redo mitral valve replacement [Re-MVR]) underwent repeat procedure for mitral prosthesis/ring degeneration. Propensity score matching distinguished 79 patient pairs. European System for Cardiac Operative Risk Evaluation (EuroSCORE) II-predicted risk was 15.7 ± 13.7% in the TM-ViV group and 15.0% ± 12.7% in the Re-MVR group (P = .5336). TM-ViV patients were older (74.73 vs 72.2 years; P = .0030) and had higher incidence of atrial fibrillation (54 vs 40 patients; P = .0233). Severe TR incidence was similar (17.95% in TM-ViV vs 14.10%; P = .1741). Sixty-eight TM-ViV patients previously underwent mitral valve replacement, whereas 41 Re-MVR patients underwent valve repair (P < .0001). Stenosis was the leading degeneration mechanism in 42 TM-ViV versus 22 Re-MVR patients (P < .0005). The 30-day/midterm mortality did not differ between groups. Moderate or greater TR was a predictor of total (odds ratio [OR], 4.36; P = .0011), 30-day (OR, 3.76; P = .0180), and midterm mortality (OR, 4.30; P = .0378), irrespective of group. CONCLUSIONS: In both groups, observed mortality was less than predicted. Redo surgery enabled treatment of concomitant conditions, such as atrial fibrillation or TR. TR was shown to be a predictor of total, 30-day, and midterm mortality in both groups.

Conventional cardiac surgery in patients with end-stage coronary artery disease: yesterday and today.

Surgical therapy of combined coronary artery disease (CAD) and heart failure, also referred to as end-stage CAD, has evolved throughout the years and patients are currently being offered traditional coronary artery bypass grafting (CABG), with or without surgical ventricle restoration (SVR), interventions for ischemic mitral valve regurgitation, heart transplantation or implantation of mechanical cardiovascular support systems. Among surgical methods, operative myocardial revascularization (with or without ventricle restoration) is still playing an important role, aiming at restoration of proper myocardial perfusion, especially if heart muscle viability is present. Facing the donor shortage, CABG may constitute a valuable alternative to transplantation in selected patients. In individuals considered not suitable for surgical revascularization, implantation of mechanical circulatory support (MCS) not only appears as a salvage procedure, but also allows for reevaluation of future therapy directions. This article aims at providing an overview of evolving and current surgical practices in patients with end-stage CAD.

Evaluation of hemodynamic and regional tissue perfusion effects of minimized extracorporeal circulation (MECC).

Minimized extracorporeal circulation (MECC, Maquet, Cardiopulmonary AG, Hirrlingen, Germany) is an established procedure to perform coronary revascularization. Studies showed positive effects of MECC compared to conventional cardiopulmonary bypass (CCPB) procedures in terms of transfusion requirements, less inflammation reactions, and neurological impairments. Recent retrospective studies showed higher mean arterial pressure (MAP) and a lower frequency of vasoactive drug use. We addressed this issue in this study. The hypothesis was to find a higher MAP during coronary bypass grafting surgery in patients treated with MECC systems. We performed a prospective, controlled, randomized trial with 40 patients either assigned to MECC (n = 18) or CCPB (n = 22) undergoing coronary bypass grafting. Primary endpoints were the perioperative course of mean arterial pressure, and the consumption of norepinephrine. Secondary endpoints were the regional cerebral and renal oxygen saturation (rSO2) as an indicator of area perfusion and the course of hematocrit. Clinical and demographic characteristics did not significantly differ between both groups. Thirty-day mortality was 0%. At four of five time points during extracorporeal circulation (ECC) MAP values were significantly higher in the MECC group compared to CCPB patients (after starting the ECC 60 +/- 11 mmHg vs. 49 +/- 10 mmHg, p = .002). MECC patients received significantly less norepinephrine (MECC 22.5 +/- 35 microg vs. CCPB 60.5 +/- 75 microg, p = .045). The rSO2 measured at right and left forehead and the renal area was similar for both groups during ECC and significantly higher at CCPB group 1 and 4 hours after termination of CPB. Minimized extracorporeal circulation provides a higher mean arterial pressure during ECC and we found a lower consumption of vasoactive drugs in the MECC group. There was a decrease in regional tissue saturation at 1 and 4 hours post bypass in the MECC group possibly due to increased systemic inflammation and extravascular fluid shift in the CCPB group.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS).

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Prognosis after the implantation of an intra-aortic balloon pump in cardiac surgery calculated with a new score.

BACKGROUND: Over the past decade, the use of a ventricular-assist device (VAD) in patients with postcardiotomy cardiogenic shock has resulted in hospital discharge rates of 25% to 40% and is improving. Nevertheless, indications for and timing of the implantation of a VAD in patients who have received an intra-aortic balloon pump (IABP) remain unclear. METHODS AND RESULTS: From July 1996 to March 2000, 391 patients with cardiac low-output syndrome who underwent open-heart surgery and had an IABP implanted were analyzed in a retrospective pilot study. The perioperative mortality was 34% (133 patients). Clinical parameters were analyzed 1 hour after IABP support began. Statistical multivariate analysis showed that patients with an adrenaline requirement higher than 0.5 microg x kg(-1) x min(-1), a left atrial pressure >15 mm Hg, urine output <100 mL/h, and mixed venous saturation (SVO(2)) <60% had poor outcomes. Using this data, we developed an IABP score (0 to 5 points) to predict survival early after IABP implantation in cardiac surgery. We evaluated our score by monitoring another 101 patients as a control group prospectively. Additionally, 210 patients who received coronary artery bypass grafting (CABG) exclusively were analyzed. All investigations confirmed the validity of the score. CONCLUSIONS: The IABP score can predict survival early after IABP implantation. In patients with a high IABP score, implantation of a VAD should be considered.

Natriuretic peptides and E-selectin as predictors of acute deterioration in patients with inotrope-dependent heart failure.

OBJECTIVE: In patients with inotrope-dependent end-stage heart failure the timely application of the most suitable treatment, i.e. heart transplantation, implantation of a ventricular assist device or conservative treatment, is a key issue for therapeutic success. METHODS: Seventy-six inotrope-dependent patients with end-stage heart failure were enrolled. Measurements of hemodynamics, routine laboratory parameters, and clinical examination were performed daily. Additionally, natriuretic peptides (BNP and NT-proBNP) and E-selectin were measured at the end of the study. The patients were retrospectively divided into groups with regard to the following end-points: Group I-deterioration into cardiogenic shock after an initially stable clinical course (n=26); Group II-stable clinical course without deterioration into cardiogenic (n=41); Group III-weaning from inotropic support (n=9). RESULTS: One day before cardiogenic shock occurred, BNP, NT-proBNP and E-selectin were significantly elevated in group I compared with group II. A logistic regression model showed that only BNP and E-selectin were independent predictors of clinical deterioration on the following day. The odds ratio (OR) for E-selectin using a cut-off point of 65ng/ml was 8.7 and for BNP using a cut-off of 500pg/ml it was 4.8. In combination, the OR increased to 11.1. Continuous decrease of NT-proBNP predicted patients in whom weaning from inotropes was possible. CONCLUSIONS: While routine parameters did not predict the clinical course, elevated BNP and E-selectin independently predicted cardiogenic shock on admission and 1 day before its occurrence. The combination showed increased predictive value.

A retrospective comparative study of minimally invasive extracorporeal circulation versus conventional extracorporeal circulation in emergency coronary artery bypass surgery patients: a single surgeon analysis.

OBJECTIVES: At the moment, the main application of minimally invasive extracorporeal circulation (MiECC) is reserved for elective cardiac operations such as coronary artery bypass grafting (CABG) and/or aortic valve replacement. The purpose of this study was to compare the outcome of emergency CABG operations using either MiECC or conventional extracorporeal circulation (CECC) in patients requiring emergency CABG with regard to the perioperative course and the occurrence of major adverse cardiac and cerebral events (MACCE). METHODS: We analysed the emergency CABG operations performed by a single surgeon, between January 2007 and July 2013, in order to exclude the differences in surgical technique. During this period, 187 emergency CABG patients (113 MiECC vs 74 CECC) were investigated retrospectively with respect to the following parameters: in-hospital mortality, MACCE, postoperative hospital stay and perioperative transfusion rate. RESULTS: The mean logistic European System for Cardiac Operative Risk Evaluation was higher in the CECC group (MiECC 12.1 ± 16 vs CECC 15.0 ± 20.8, P = 0.15) and the number of bypass grafts per patient was similar in both groups (MiECC 2.94 vs CECC 2.93). There was no significant difference in the postoperative hospital stay or in major postoperative complications. The in-hospital mortality was higher in the CECC group 6.8% versus MiECC 4.4% (P = 0.48). The perioperative transfusion rate was lower with MiECC compared with CECC (MiECC 2.6 ± 3.2 vs CECC 3.8 ± 4.2, P = 0.025 units of blood per patient). CONCLUSIONS: In our opinion, the use of MiECC in urgent CABG procedures is safe, feasible and shows no disadvantages compared with the use of CECC. Emergency operations using the MiECC system showed a significantly lower blood transfusion rate and better results concerning the unadjusted in-hospital mortality.

Tissue-engineering bioreactors: a new combined cell-seeding and perfusion system for vascular tissue engineering.

One approach to the tissue engineering of vascular structures is to develop in vitro conditions in order ultimately to fabricate functional vascular tissues before final implantation. In our experiment, we aimed to develop a new combined cell seeding and perfusion system that provides sterile conditions during cell seeding and biomechanical stimuli in order to fabricate autologous human vascular tissue in vitro. The cell seeding and perfusion system is made of Plexiglas and is completely transparent (Berlin Heart, Berlin, Germany; University Hospital Benjamin Franklin, Berlin, Germany). The whole system consists of a cell seeding chamber that can be incorporated into the perfusion system and an air-driven respirator pump connected to the bioreactor. The cell culture medium continuously circulates through a closed-loop system. We thus developed a cell seeding device for static and dynamic seeding of vascular cells onto a polymeric vascular scaffold and a closed-loop perfused bioreactor for long-term vascular conditioning. The cell seeding chamber can be easily connected to the bioreactor, which combines continuous, pulsatile perfusion and mechanical stimulation to the tissue-engineered conduit. Adjusting the stroke volume, the stroke rate, and the inspiration/expiration time of the ventilator allows various pulsatile flows and different levels of pressure. The whole system is a highly isolated cell culture setting, which provides a high level of sterility and a gas supply and fits into a standard humidified incubator. The device can be sterilized by ethylene oxide and assembled with a standard screwdriver. Our newly developed combination of a cell seeding and conditioning device provides sterile conditions and biodynamic stimuli for controlled tissue development and in vitro conditioning of an autologous tissue-engineered vessel.

Factors influencing results and outcome after transmyocardial laser revascularization.

BACKGROUND: Transmyocardial laser revascularization (TMR) has been increasingly used during the recent past for patients with diffuse coronary artery disease. Because this operation is associated with significant morbidity and mortality, it is important to select patients for TMR who are likely to benefit from the procedure. METHODS: We performed an univariate logistic regression analysis of 20 factors on the benefits and outcomes of 134 patients who underwent isolated TMR at our institution between November 1994 and May 2000. RESULTS: Responders and nonresponders differed significantly with regard to the incidence of diabetes mellitus. For diabetic patients the chance of profiting from the TMR operation was only 43% of that of nondiabetic patients (odds ratio = 0.43 [0.20 to 0.92]). Furthermore, patients with a preoperative body mass index of less than 25 had a threefold increase in the probability of death during the first year after TMR as compared to patients whose body mass index was 25 or more (odds ratio = 2.97 [1.05 to 8.40]). The incidence of diabetes was also slightly but not significantly different between 1-year survivors and nonsurvivors. CONCLUSIONS: In diabetic patients we recommend caution in selecting therapeutic TMR because outcomes are less satisfactory than in nondiabetics. Furthermore, patients with a body mass index below 25 have a significantly higher risk for death during the first postoperative year. Studies based on larger patient populations should follow.

New approach in treatment of acute cardiogenic shock requiring mechanical circulatory support.

In 12 patients with acute cardiogenic shock who required mechanical circulatory support a short-term Abiomed BVS 5000 extracorporeal assist device was implanted using the inflow and outflow cannulas of the BerlinHeart extracorporeal assist device. In 7 patients suitable for long-term support the Abiomed pumps were later exchanged for BerlinHeart pumps. This approach avoids the risks associated with repeat sternotomy and use of cardiopulmonary bypass and decreases the total costs of patient care.

Factors excercising an influence on recovery of hibernating myocardium after coronary artery bypass grafting.

OBJECTIVE: Coronary artery bypass grafting (CABG) in patients with endstage coronary disease (CAD) significantly improves symptoms and prolongs life expectancy. Left ventricular function is also improved in some patients, but not in others. Factors which influence functional recovery of hibernating myocardium after revascularization are at present under investigation. METHODS: From 3/2000 to 8/2002, we analyzed 41 patients with an ejection fraction (EF) of < or =30%, who underwent CABG, prospectively. All patients received low-dose dobutamine echocardiography (DE), dobutamine myocardial scintigraphy with SPECT, dobutamine magnetic resonance tomography (MRI), contrast-enhanced MRI and, when necessary, positron emission tomography (PET). Hibernating myocardium (area of interest) was identified with these diagnostic tools preoperatively and biopsy samples were taken intraoperatively. RESULTS: All patients received complete coronary revascularization. Early mortality was 2.4%. Three patients died during follow-up. Six months after the operation DE, MRI and SPECT were repeated. EF increased in 23 patients (group I) by at least >or =5%, and in 14 patients (group II) it did not improve. The wall motion score in the area of interest had increased during preoperative DE in group I significantly. The score did not change in group II. In addition the diastolic-systolic wall thickness increase in the area of interest rose >15% during DE in group I preoperatively; the increase was < or =15% in group II. MRI hyperenhancement of the left ventricle was significantly lower in group I compared to group II preoperatively. SPECT showed myocardial viability in the area of interest in all 37 patients. There were no significant differences between group I and II seen in SPECT. When the area of interest was located in the anterior wall the patients more frequently showed ventricular improvement postoperatively than patients with an area of interest located in the inferior, lateral or posterior wall. Light microscopy showed more severe myocardial cell hypertrophy (>19 microm) and less severe destruction of myocardial cell architecture in biopsies of group I compared to group II (myocardial cell hypertrophy < or =17 microm). Electron microscopy showed mitochondrial abnormalities in size and shape, lack of contractile material and large areas containing nonspecified cytoplasm, lipid droplets, and large glycogen-filled regions, but no significant differences between the two groups. Gene expresssion of the pro-apoptotic genes BAK and BAX was lowered compared to expression in 'normal' myocardium. The anti-apoptotic gene BCL-XL was significantly more expressed in the 'area of interest' of group II patients than in group I patients. CONCLUSIONS: We conclude that in patients with endstage CAD myocardial recovery after coronary revascularization can be predicted using DE and MRI preoperatively. Myocardial regions without any potential of functional recovery show less adaptation (less pronounced myocardial cell hypertrophy), a more severe degree of myocardial architecture destruction and a higher degree of anti-apoptotic gene expression. We recommend a myocardial biopsy when DE and MRI are not favorable in a patient with end stage coronary artery disease referred to us with the option of heart transplantation or coronary bypass.

[Surgical revascularization in patients with diabetes mellitus]. / Koronarchirurgie bei Diabetes mellitus.

Patients with coronary artery disease (CAD) and diabetes mellitus have an increased risk of mortality when undergoing either interventional or surgical revascularization. However, the rate of necessary reinterventions is significantly lower after surgical revascularization than after percutaneous transluminal coronary angioplasty (PTCA). As yet, no results of long-term follow-up after stent implantation are available. The risk for a patient with diabetes mellitus and CAD of dying of myocardial infarction after a bypass operation is significantly lower than after PTCA. Bypass operation with sternotomy in patients with diabetes mellitus carries, however, an increased risk of postoperative mediastinitis, especially when both internal thoracic arteries are used for "totally arterial" revascularization. For this reason the internal thoracic artery should be used only unilaterally in surgical revascularization in these patients. Preoperative and postoperative stabilization of the blood sugar level is very important. Sclerosis of the vessels in close proximity to the heart (ascending aorta, carotid arteries) must be clarified preoperatively. The operation should be carried out particularly carefully, with the wound area kept as small as possible. Reexploration should definitely be avoided. If these guidelines are followed, surgical revascularization in patients with CAD and diabetes mellitus can achieve very good results.

Development of a database of patients supported by ventricular assist devices.

An increase in the number of patients with end stage heart failure is leading to increased use of ventricular assist devices (VAD). However, sometimes the optimal time point for implantation of left ventricular or biventricular support remains unclear. Data analysis using an electronic database may help to make the decision making process more precise and thus improve outcome. However, it is not easy to find a balance between sufficient comprehensiveness of the data, which are selected from a huge amount of available information, and practicability of database maintenance and data analysis. We developed the Assist Database based on Access for Windows. The Assist Database consists of five main parts: (1) demographic and admission data, diagnosis, goal, and type of VAD; (2) preoperative period; (3) postoperative period up to 30 days; (4) follow-up period; and (5) statistical evaluation. The preoperative and postoperative parts include hemodynamic data; ventilatory support; laboratory results; results from echocardiographic, neurologic, pathologic, and other examinations; medication; and complications. The follow-up part documents readmissions, complications, and outcome. From April 1987 to October 2002, eight different types of VAD were implanted in 654 patients in our institution. Their data were retrospectively added to the Assist Database using medical records and different previously used electronic databases. Since the Assist Database came into routine use, it has been supplied daily with selected data of current patients. On the data entry level, the data arising from medical records are entered either manually via standard forms or automatically from other electronic documentation systems used in our hospital in routine patient care to collect laboratory results, demographic data, blood transfusion data, and operative data and from electronic patient charts via interfaces. The structure of the database is designed to facilitate the data analysis level. The database presented is one of three databases united to form a network. The structure of the Assist Database facilitates comprehensive, time saving data collection, which allows different online data analyses. These analyses may affect the decision making process and thus improve outcome. However, achieving a balance between the volume of available information, the time consumed, and the relevance of the data for further analysis remains difficult. The Assist Database should include information relevant for the decision making process and for the prediction of outcome. In particular, data collection should be focused on patients' preoperative condition and on postoperative organ function and quality of life. Further, different databases (for patients with congestive heart failure, assist device patients, and transplanted patients) should be unified to form a network to avoid the repeated collection of identical data, to save time, and to increase the quality of analysis. In the long-term, multicenter use of the Assist Database could be considered.

Application of stereolithography for scaffold fabrication for tissue engineered heart valves.

A crucial factor in tissue engineering of heart valves is the functional and physiologic scaffold design. In our current experiment, we describe a new fabrication technique for heart valve scaffolds, derived from x-ray computed tomography data linked to the rapid prototyping technique of stereolithography. To recreate the complex anatomic structure of a human pulmonary and aortic homograft, we have used stereolithographic models derived from x-ray computed tomography and specific software (CP, Aachen, Germany). These stereolithographic models were used to generate biocompatible and biodegradable heart valve scaffolds by a thermal processing technique. The scaffold forming polymer was a thermoplastic elastomer, a poly-4-hydroxybutyrate (P4HB) and a polyhydroxyoctanoate (PHOH) (Tepha, Inc., Cambridge, MA). We fabricated one human aortic root scaffold and one pulmonary heart valve scaffold. Analysis of the heart valve included functional testing in a pulsatile bioreactor under subphysiological and supraphysiological flow and pressure conditions. Using stereolithography, we were able to fabricate plastic models with accurate anatomy of a human valvular homograft. Moreover, we fabricated heart valve scaffolds with a physiologic valve design, which included the sinus of Valsalva, and that resembled our reconstructed aortic root and pulmonary valve. One advantage of P4HB and PHOH was the ability to mold a complete trileaflet heart valve scaffold from a stereolithographic model without the need for suturing. The heart valves were tested in a pulsatile bioreactor, and it was noted that the leaflets opened and closed synchronously under subphysiological and supraphysiological flow conditions. Our preliminary results suggest that the reproduction of complex anatomic structures by rapid prototyping techniques may be useful to fabricate custom made polymeric scaffolds for the tissue engineering of heart valves.

A prospective randomised multicentre clinical comparison of a minimised perfusion circuit versus conventional cardiopulmonary bypass.

OBJECTIVE: Minimised perfusion circuits (MPCs) are expected to reduce the side effects of conventional cardiopulmonary bypass (CCPB); however, conclusive data from sufficiently powered clinical trials are lacking. The purpose of this study was to evaluate the safety and efficacy of the ROCsafeRX minimised perfusion circuit. METHODS: A randomised, controlled, multicentre clinical trial comparing both perfusion circuits in patients subjected to elective coronary artery bypass and/or aortic valve replacement is described. The primary end points of safety, defined as procedure success without device-related complications, and secondary end point of efficacy, including reduction of transfusion requirement and incidence of atrial fibrillation, are analysed. RESULTS: To date, 291 patients have been enrolled and randomised (146 MPC vs 145 CCPB). With the exception of a significantly higher male population in the MPC group (83.6% vs 71.0%, p=0.01), both groups were well matched for demographic data and type of surgery. There were no device-related complications but a hard-shell reservoir had to be integrated in one MPC because of a tear in the right atrium that was managed uneventfully. Total transfusion requirement (329+/-599 ml vs 783+/-1638 ml, p < or = 0.001) and erythrocyte transfusion (181+/-341 ml vs 434+/-798 ml, p < or = 0.001) were significantly reduced in the MPC group. The incidence of atrial fibrillation was significantly lower in the MPC group (7.1% vs 19.5%, p < or = 0.01), while freedom of major adverse events showed no significant difference. CONCLUSIONS: Lack of device-related complications combined with a significant reduction in postoperative atrial fibrillation and transfusion requirements have shown the ROCsafeRX MPC to be both safe and efficient for large-scale use in cardiac patients. Additional data are expected to confirm these initial findings.