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G Laufer

Publications and source records attributed to G Laufer.

At least 19 recordsLinked to original sources
PubMed2006

Electromechanical synchronization of the heterotopic and native heart by dual atrial stimulation following heart transplantation.

After heterotopic heart transplantation, a 59-year-old woman presented with remarkable symptoms of breathlessness and fatigue, despite excellent donor heart function. Asynchrony of donor and native heart provoked haemodynamic instability. Dual atrial pacemaker implantation lead to linkage and synchronization of atrial and ventricular contraction in both the donor and native heart with the faster organ executing the synchronization. Remarkable relief of symptoms has been evident during the long-term follow-up.

Arrhythmia, Sinus↗
PubMed2006

Technical challenges in totally endoscopic robotic coronary artery bypass grafting.

OBJECTIVE: Robotic technology is a prerequisite for performance of totally endoscopic coronary artery bypass grafting. During the implementation phase of totally endoscopic coronary artery bypass, surgeon-related technical difficulties might be encountered. It was the aim of this study to assess the incidence of these challenges, to find risk factors, and to describe clinical results associated with technical errors. METHODS: From October 2001 through October 2004, 40 patients received robotically assisted totally endoscopic left internal thoracic artery grafts to the left anterior descending coronary artery system with the da Vinci telemanipulation device. All patients underwent remote access cardiopulmonary bypass perfusion through groin access, and all anastomoses were performed on the arrested heart. RESULTS: Undesirable technical events of various grades occurred in 20 (50%) of 40 patients: bleeding from a port hole in 3 (8%), left internal thoracic artery damage in 3 (8%), epicardial lesion in 3 (8%), remote access perfusion problems in 9 (23%), bleeding from the anastomosis in 4 (10%), and anastomotic stenosis in 2 (5%). There was no hospital mortality. The following differences were noted between patients without technical difficulties (group 1) and those in whom problems occurred (group 2): total operative time of 314 minutes (260-540 minutes) versus 418 minutes (270-690 minutes; P = .007), ventilation time of 6 hours (0-26 hours) versus 14 hours (0-278 hours; P = .004), intensive care unit stay of 20 hours (11-70 hours) versus 44 hours (16-336 hours; P=.183), hospital stay of 7 days (4-13 days) versus 8 days (5-21 days; P = .038), and cumulative freedom from angina at 36 months of 93% versus 100% (P = .317). CONCLUSION: We conclude that technical difficulties during totally endoscopic coronary artery bypass grafting translate into markedly increased operative time, moderately prolonged postoperative ventilation time, and slightly increased hospital stay. Short-term survival and freedom from angina, however, do not seem to be compromised.

Adult↗
PubMed2006

Superior prevention of acute rejection by tacrolimus vs. cyclosporine in heart transplant recipients--a large European trial.

We compared efficacy and safety of tacrolimus (Tac)-based vs. cyclosporine (CyA) microemulsion-based immunosuppression in combination with azathioprine (Aza) and corticosteroids in heart transplant recipients. During antibody induction, patients were randomized (1:1) to oral treatment with Tac or CyA. Episodes of acute rejection were assessed by protocol biopsies, which underwent local and blinded central evaluation. The full analysis set comprised 157 patients per group. Patient/graft survival was 92.9% for Tac and 89.8% for CyA at 18 months. The primary end point, incidence of first biopsy proven acute rejection (BPAR) of grade >/= 1B at month 6, was 54.0% for Tac vs. 66.4% for CyA (p = 0.029) according to central assessment. Also, incidence of first BPAR of grade >/= 3A at month 6 was significantly lower for Tac vs. CyA; 28.0% vs. 42.0%, respectively (p = 0.013). Significant differences (p < 0.05) emerged between groups for these clinically relevant adverse events: new-onset diabetes mellitus (20.3% vs. 10.5%); post-transplant arterial hypertension (65.6% vs. 77.7%); and dyslipidemia (28.7% vs. 40.1%) for Tac vs. CyA, respectively. Incidence and pattern of infections over 18 months were comparable between groups, as was renal function. Primary use of Tac during antibody induction resulted in superior prevention of acute rejection without an associated increase in infections.

Acute Disease↗
PubMed2005

Ongoing procedure development in robotically assisted totally endoscopic coronary artery bypass grafting (TECAB).

BACKGROUND: Totally endoscopic coronary artery bypass grafting (TECAB) using robotics requires stepwise introduction into a heart surgery program. It is the aim of this study to evaluate the state of procedure development after continued application of telemanipulation techniques in the clinical setting. We also sought to assess perioperative and intermediate term clinical results after robotically assisted CABG. PATIENTS AND METHODS: From June 2001 to March 2005, robotically assisted CABG using the daVinci system was carried out in 107 patients with single and multi-vessel coronary artery disease. The following procedures were performed: robotically assisted endoscopic left internal mammary artery (LIMA) harvesting and completion of the procedure as conventional CABG, MIDCAB, or OPCAB (n = 22), robotically assisted suturing of LIMA-to-LAD anastomoses during conventional CABG (n = 28), TECAB on the arrested heart using remote access perfusion (n = 48), TECAB on the beating heart using an endostabilizer (n = 8), takedown of adhesions (TECAB intended) (n = 1). RESULTS: Hospital mortality was 0% and cumulative risk adjusted mortality reached 1.6 lives saved versus EuroSCORE predictions. Undesirable surgical events (USE) such as conversion, on table revision, or postoperative revision procedures occurred in 34 out of 107 (32%) patients. Median ventilation time and ICU stay, however, were 11(0-278) hours and 21(11-389) hours, respectively. Cumulative 3 years survival was 100% and freedom from angina at 3 years was 97%. CONCLUSIONS: We conclude that despite being surgically challenging robotically assisted coronary artery surgery can be implemented with acceptable safety. TECAB procedures have reached a reproducible state. Perioperative mortality after robotically assisted CABG may be lower than predicted. Intermediate term clinical results are very satisfactory.

Adult↗
PubMed2005

Hybrid coronary artery revascularization: logistics and program development.

Planning hybrid coronary artery revascularization--a combination of cardiac surgery with percutaneous procedures--requires, at first sight, a very complex logistical setup. Technical and equipment related details should be defined as early as possible in order to have time for training of all OR personnel involved. The most challenging aspect in OR-located hybrid coronary revascularization remains a very close cooperation of cardiac surgeons and interventional cardiologists. This teamwork does include indication findings and subsequent referral of multivessel coronary artery disease patients to hybrid procedures, as well as high individual flexibility of interventionalists and surgeons. The major prerequisite for this cooperation is a mutual acceptance of different revascularization approaches and the intent to combine their most striking advantages. Intraoperative graft angiography during coronary artery bypass grafting (CABG) procedures is one important step toward simultaneous hybrid coronary revascularization procedures. We describe our experience with on table angiography using a mobile C-arm for intraoperative imaging. This fluoroscopy system can in selected cases be used for simultaneous hybrid procedures.

Adult↗
PubMed2005

Factors associated with mortality and long time survival in patients undergoing modified Bentall operations.

AIM: We report our results on mortality, morbidity and long time events after composite graft replacement of the aortic root and ascending aorta/aortic arch and factors associated with them. METHODS: Seventy-four patients, aged 52 years (15-73) underwent modified ''button'' Bentall operation. The indication for operation was acute dissection in 29 (39%) patients, chronic dissection in 3 (4%), aortic regurgitation after previous replacement of the ascending aorta because of aortic dissection in 2 (3%) and non dissecting aneurysm in 40 (54%). Concommitant procedures were (partial) replacement of the aortic arch in 11 (15%) and coronary artery bypass grafting in 5 (7%). Six patients (8%) had undergone previous cardiac surgery. Mean follow up was for 49 +/- 46 months (maximum 198). RESULTS: Length of intensive care unit (ICU) stay was 3 days (1-72). Hospital mortality was 12%. Factors significantly associated with hospital mortality were: aortic dissection, cardiopulmonary bypass time, aortic cross clamp time, deep hypothermic circulatory arrest, low cardiac output syndrome, revision due to bleeding, renal failure requiring hemofiltration, multisystemic organ failure and sepsis. None of these factors was significantly associated with long term survival. Survival rates including hospital deaths were 86%, 84%, 75% and 75% after 1, 3, 5 and 7 years respectively. Pseudoaneurysm at the composite graft occurred in 3%, infection of the prosthesis in 1%. Neither valve thrombosis nor thromboembolic events occurred postoperatively. CONCLUSIONS: Modified Bentall operation is a demanding operation with acceptable hospital mortality. The long time survival rates are good and the big majority of patients is eventfree after operation.

Adolescent↗
PubMed2004

On the fate of skeletal myoblasts in a cardiac environment: down-regulation of voltage-gated ion channels.

We have analysed the voltage-gated ion channels and fusion competence of skeletal muscle myoblasts labelled with green fluorescent protein (GFP) and the membrane dye PKH transplanted into the infarcted myocardium of syngenic rats. After cell transplantation the animals were killed and GFP(+)-PKH(+) myoblasts enzymatically isolated for subsequent studies of ionic currents through voltage-gated sodium, calcium and potassium channels. A down-regulation of all three types of ion channels after engraftment was observed. The fraction of cells with calcium (68%) and sodium channels (65%) declined to zero within 24 h and 1 week, respectively. Down-regulation of potassium currents (90% in control) occurred within 2 weeks to about 30%. Before injection myoblasts expressed predominantly transient outward potassium channels whereas after isolation from the myocardium exclusively rapid delayed rectifier channels. The currents recovered completely between 1 and 6 weeks under cell culture conditions. The down-regulation of ion channels and changes in potassium current kinetics suggest that the environment provided by infarcted myocardium affects expression of voltage-gated ion channels of skeletal myoblasts.

Animals↗
PubMed2004

Combined transplantation of skeletal myoblasts and bone marrow stem cells for myocardial repair in rats.

OBJECTIVES: To prove whether intramyocardial transplantation of combined skeletal myoblasts (SM) and mononuclear bone marrow stem cells is superior to the isolated transplantation of these cell types after myocardial infarction in rats. METHODS: In 67 male Fischer rats myocardial infarction was induced by direct ligature of the LAD. Seven days postinfarction baseline echocardiography and intramyocardial cell transplantation were performed. Via lateral thoracotomy 200 microl containing either 10(7) SMs or 10(7) bone marrow-derived mononuclear cells (BM-MNC) or a combination of 5x10(6) of both cell types (MB) were injected in 10-15 sites in and around the infarct zone. In controls (C) 200 microl of cell-free medium were injected in the same manner. Before injection both cell types were stained using a fluorescent cell linker kit (PKH, Sigma). In addition, SMs were transfected with green fluorescent protein. Nine weeks postinfarction follow-up echocardiography was performed and animals were sacrificed for further analysis. RESULTS: At baseline echocardiography there was no difference in left ventricular ejection fraction (LVEF; C, SM, BM-MNC, MB: 60.1+/-3.2, 53.3+/-10.2, 53.1+/-8.7, 49+/-9.0%) and left ventricular end diastolic diameter (LVEDD; C, SM, BM-MNC, MB: 6.5+/-0.8, 5.17+/-0.8, 5.77+/-1.4, 6.25+/-0.8 mm) between the different therapeutic groups. Eight weeks after cell transplantation LVEDD was significantly increased in all animals except those that received a combination of myoblasts and bone marrow stem cells (MB; C, SM, BM-MNC, MB: 7.7+/-0.6 mm, P=0.001; 7.7+/-1.5 mm, P<0.001; 7.7+/-1.1 mm, P=0.005; 6.6+/-1.7 mm, P=0.397. At the same time LVEF decreased significantly in the control group (C), stayed unchanged in animals that received bone marrow stem cells (BM-MNC) and increased in animals that received myoblasts (SM) and a combination of both cell types (MB; C, SM, BM-MNC, MB: 45.3+/-7.0%, P=0.05; 63.9+/-15.4%, P=0.044; 54.3+/-6.3%, P=0.607; 63.0+/-11.5%, P=0.039). CONCLUSIONS: The present data show that the concept of combining SMs with bone marrow-derived stem cells may be of clinical relevance by merging the beneficial effects of each cell line and potentially reducing the required cell quantity. Further studies are required to identify the exact mechanisms underlying this synergy and to allow full exploitation of its therapeutic potential.

Animals↗
PubMed2004

Robotic totally endoscopic coronary artery bypass: program development and learning curve issues.

BACKGROUND: The introduction of new procedures in heart surgery is a critical phase that includes learning curves and the risk of increased mortality or morbidity. Totally endoscopic coronary artery bypass grafting using robotic techniques represents such an innovative procedure. The aim of this report is to demonstrate the safe introduction of totally endoscopic coronary artery bypass grafting using a stepwise and modular approach. METHODS: From June 2001 until December 2002, 50 procedures were performed using the da Vinci telemanipulator system. After baseline training the following procedure modules were carried out in a stepwise manner: robotically assisted endoscopic left internal thoracic artery harvesting and completion of the procedure as conventional coronary artery bypass grafting, minimally invasive direct coronary artery bypass, or off-pump coronary artery bypass (n = 19), robotically assisted suturing of left internal thoracic artery to left anterior descending anastomoses during conventional coronary artery bypass grafting (n = 15), totally endoscopic coronary artery bypass grafting on the arrested heart using remote access perfusion and aortic endocclusion coronary bypass grafting (n = 15). One patient was excluded intraoperatively from a robotic procedure due to pleural adhesions. RESULTS: A significant learning curve was observed for left internal thoracic artery takedown time, y(min) = 181 - 39 x ln(x) (x = procedure number) (P <.001), and total operative time in totally endoscopic coronary artery bypass grafting, y(min) = 595 - 87 x ln(x) x = (procedure number) (P =.028). The conversion rate in totally endoscopic coronary artery bypass grafting was 2/15. Intensive care unit stay correlated significantly with total operative time (r =.427, P =.002). There was no hospital mortality. CONCLUSION: Totally endoscopic coronary artery bypass grafting can be safely implemented into a heart surgery program. Learning curves are steep for robotic left internal thoracic artery takedown and for performance of totally endoscopic coronary artery bypass grafting. Long operative times translate into prolonged intensive care unit stay in specific cases but not into increased mortality.

Adult↗
PubMed2004

Is the axillary artery a suitable cannulation site in aortic surgery?

AIM: The axillary artery is currently gaining interest as an alternative to femoral artery cannulation in aortic surgery. It was the aim of our study to evaluate the feasibility, safety, and efficacy of axillary artery cannulation in a series of patients undergoing surgery of the ascending aorta and/or the aortic arch. METHODS: From 1998 to 2002 cardiopulmonary bypass (CPB) perfusion via the axillary artery was intended in 35 patients (28 male), median age 61 (22-77) years. The underlying disease was acute aortic dissection type A in 22/35 (63%), chronic aortic dissection type A in 2/35 (6%), ascending aortic aneurysm in 8/35 (22%), aortic regurgitation after previous ascending aortic replacement in 1/35 (3%), pseudoaneurysm after Bentall operation in 1/35 (3%) and coronary artery disease with severe arteriosclerosis of the aorta in 1/35 (3%). RESULTS: Conversion to femoral artery or ascending aortic cannulation was necessary in 3 patients. In the other cases, adequate CPB flows of 2.4 l/m2/min were achieved. In 1 case local dissection of the axillary artery occurred after emergency cannulation. No postoperative complications related to axillary artery cannulation, such as upper extremity ischemia, brachial plexus injury, or local wound infection occurred. No new postoperative stroke was noted, hospital mortality was 4/35 (11%) patients. CONCLUSION: Axillary artery cannulation is feasible in the majority of cases and seems to be a safe and effective method in surgery of the ascending aorta and aortic arch. Several disadvantages of femoral artery cannulation and perfusion can be avoided.

Adult↗
PubMed2004

A variation of the radial artery and its clinical implications for coronary artery bypass grafting.

Since the radial artery is increasingly harvested as a bypass graft, surgeons are confronted with its anatomical variations. We report on a radial artery running laterally around the distal part of the radius, while a superficial palmar branch is running straight down. The radial artery can be dissected distally to get enough length for the bypass graft, but attention has to be paid to the superficial branch of the radial nerve running nearby to prevent postoperative paresthesias and numbness. The superficial palmar branch of the radial artery can be ligated. Allen's test in such a case is not valid because it is always negative.

Aged↗
PubMed2003

Rapamycin as rescue therapy in a patient supported by biventricular assist device to heart transplantation with consecutive ongoing rejection.

Rapamycin is a new immunosuppressive agent that has been shown to be effective in acute heart allograft rejection. This case documents a patient suffering from cardiac sarcoidosis who was bridged to transplantation for 90 days with ongoing rejection after allograft implantation. Rejection did not abate despite treatment with antithymocyte globulin (ATG), FK506, a mycophenolate switch and courses of multiple apheresis. Initiation of rapamycin treatment resulted in a rapid resolution of cardiac rejection and reduction of concomitant immunosuppressive agents with few side-effects. Most notably was the reduction of panel reactive antibodies within a few weeks after the rapamycin initiation. This case illustrates that the utilization of rapamycin ceased ongoing rejection in a patient with a clear hyperimmune state despite prior extensive utilization of a variety of immunosuppressive strategies after heart transplantation.

Adult↗
PubMed2003

Predictors of lung transplant survival in eurotransplant.

This study was undertaken to assess the influence of patient/donor and center factors on lung transplantation outcome. Outcomes of all consecutive first cadaveric lung transplants performed at 21 Eurotransplant centers in 1997-99 were analyzed. The risk-adjusted center effect on mortality was estimated. A Cox model was built including donor and recipient age and gender, primary disease, HLA mismatches, patient's residence, cold ischemic time, donor's cause of death, serum creatinine, type of lung transplant, respiratory support status, clinical condition and percentage predicted FEV1. The center effect was calculated (expressed as the standardized difference between the observed and expected survival rates), and empirical and full Bayes methods were applied to evaluate between-center differences. A total of 590 adults underwent lung transplantation. The primary disease (p=0.01), HLA-mismatches (p = 0.02), clinical condition(p < 0.0001) and the patient's respiratory support status (p = 0.05) were significantly associated with survival. After adjusting for case-mix, no between-center differences could be found. An in-depth empirical Bayes analysis showed the between-center variation to be zero. Similar results were obtained from the full Bayes analysis. Based on these data, there is no scientific basis to support a hypothesis of possible association between center volume and lung survival rates.

Adult↗
PubMed2003

Left atrial thrombus mistaken as a tumor after heart transplantation.

The occurrence of neoplastic malignancy due to chronic immunosuppression in heart transplant recipients is a well-known threat. Continuous check-ups are therefore mandatory in this patient group. We describe the case of a 58-year-old man transplanted for dilated cardiomyopathy. During regular diagnostic check-up, a solid mass in the left atrium was discovered on the transesophageal echocardiogram. Since the mass became progressively larger over three years and showed features of neither myxoma nor thrombus, a cardiac sarcoma was suspected. A secondary diagnostic magnetic resonance tomography (MRT) investigation was contraindicated due to an implanted pacemaker. Intraoperatively, the mass proved to be an organized thrombus. Surgery had to be performed without an established accurate diagnosis due to a suspected malignancy in chronically immunosuppressed patients.

Cardiomyopathy, Dilated↗
PubMed2002

Off pump coronary artery bypass grafting in EuroSCORE high and low risk patients.

OBJECTIVE: Off pump coronary artery bypass grafting (OPCAB) is claimed to reduce the operative morbidity and mortality in high risk patients. It was the aim of the study to compare the outcome of OPCAB patients classified as high- and low risk according to the EuroSCORE. METHODS: Medical records of patients undergoing off pump coronary artery bypass grafting (n=126) at our institution between 1998 and 2001 were retrospectively reviewed. We classified them into two subgroups: low risk (EuroSCORE < or = 5, n=72, male 58 (81%), female 14 (19%), age 61 (37-78) years) and high risk (EuroSCORE >5, n=54, male 32 (59%), female 22 (41%), age 73 (42-83) years). RESULTS: EuroSCORE high risk patients showed significantly higher rates of blood transfusion (70 vs 31%; P<0.0001), intraaortic balloon pump insertion (16 vs 3%; P=0.013), atrial fibrillation (43 vs 22%; P=0.014), and renal failure (13 vs 3%; P=0.028). ICU length of stay was significantly longer in the high risk group (25 vs 22 h; P=0.002). There was also a higher perioperative mortality in the high risk group (9 vs 0%; P=0.008). CONCLUSION: From these data we conclude that using off pump coronary artery bypass grafting results as predicted by the EuroSCORE can be achieved. OPCAB is safe for low risk patients. Major complications seem to occur preferentially in the high risk group.

Adult↗
PubMed2002

Extraanatomical coronary artery bypass grafts on the beating heart for management of the severely atherosclerotic ascending aorta.

BACKGROUND: Crossclamping a severely atherosclerotic ascending aorta carries a significant risk of stroke in coronary artery bypass grafting. Besides other techniques aortic no touch concepts are increasingly applied for management of this problem. METHODS: Out of 407 patients undergoing epiaortic scanning during coronary artery bypass grafting 38 (9.3%) exhibited severe ascending aortic atherosclerosis. 22 of these patients (18 male, 4 female, age 72 (57-79) years, Parsonnet Score 11 (0-18), Euro Score 8 (2-13), McSPI Stroke Risk Index 6 (1-30) %) were operated on using a beating heart and aortic no touch technique. All patients received at least one internal mammary artery (IMA) in situ graft and additional extraanatomical bypass conduits: venous Y-graft from the IMA (n=14), arterial Y-graft from the IMA (n=3), vein graft from the axillary artery (n=3), vein graft from the IMA stump (n=2), vein graft from the innominate artery (n=2). RESULTS: No stroke occurred. The rate of perioperative myocardial infarction (CKMB rt; 50 U/l) was 5/22. Median ICU length of stay was 54 (15-1245) h. Hospital mortality was 2/22. Pre- and postoperative angina class (CCSC) were 3.3 +/- 0.9 and 1.4 +/- 0.9 respectively (p<0.001). After a median follow up period of 8 months 3 deaths, one stroke, and one myocardial infarction occurred. On 3D multislice CT scan reconstructions which were performed in 13 patients during the first postoperative year all IMA grafts to the LAD and 11 out of 13 extraanatomical vein grafts were shown to be patent. CONCLUSION: Performance of beating heart extraanatomical coronary artery bypass grafts for management of a heavily diseased ascending aorta can result in a very low stroke rate despite a considerable stroke risk. The complexity of the procedures may be reflected by a relatively high rate of perioperative myocardial infarctions. Perioperative mortality as well as short term patency of extraanatomical bypass grafts seem to be acceptable.

Aged↗