Universitätspublikationen
Refine
Year of publication
Document Type
- Article (15)
- Conference Proceeding (2)
Has Fulltext
- yes (17)
Is part of the Bibliography
- no (17)
Keywords
- Aortic valve replacement (2)
- LVAD (2)
- Aortic Valve Replacement (1)
- Aortic valve (1)
- Apoptosis (1)
- Biological heart valves (1)
- Bioprosthesis (1)
- Cardiac surgery (1)
- Cell metabolism (1)
- Daptomycin (1)
Institute
- Medizin (17)
Objective: Acute kidney injury (AKI) after cardiac surgery procedures is associated with poor patient outcomes. Cystatin C as a marker for renal failure has been shown to be of prognostic value; however, a wide range of its predictive accuracy has been reported. The aim of the study was to evaluate whether the measurement of pre- and postoperative serum cystatin C improves the prediction of AKI.
Methods: In a single-centre, prospective study of 70 patients (74 ± 9ys; range 47-85ys; 77% male), cystatin C was measured six times: (T1 = preoperative, T2 = start cardiopulmonary bypass (CPB), T3 = 20 min after CPB, T4 = end of operation; T5 = 24 h postoperatively; T6 = 7d postoperatively). Predictive property, in terms of the need for renal replacement therapy (RRT), was analysed by receiver operating characteristics (ROC) statistics and described by the area under the curve (AUC).
Results: With respect to RRT (n = 8), serum cystatin C was significantly higher at the end of the operation (T4), 24 h postoperatively at T5 and at T6. The AUCs for preoperative T1 and intraoperative T2/3 cystatin C were <0.7 (95% CI, 0.47-0.85). The earliest significant predictive AUCs were found at the end of the operation (T4: p = 0.03 95% CI 0.58-0.88 AUC 0.73) and 24 h postoperatively (T5: p = 0.003 95% CI 0.74-0.96 AUC 0.85).
Conclusions: Early postoperative serum cystatin C increase appears to be a moderate biomarker in the prediction of AKI, whereas a preoperative and intraoperative cystatin C increase has only a limited diagnostic and predictive value.
Background: The aim of this study was to compare outcome of patients with previous cardiac surgery undergoing transapical aortic valve implantation (Redo-TAVI) to those undergoing classic aortic valve replacement (Redo-AVR) by using propensity analysis.
Methods: From January 2005 through May 2012, 52 high-risk patients underwent Redo-TAVI using a pericardial xenograft fixed within a stainless steel, balloon-expandable stent (Edwards SAPIEN™). During the same period of time 167 patients underwent classic Redo-AVR. Logistic regression analysis was used to identify covariates among 11 baseline patient variables including the type of initial surgery. Using the significant regression coefficients, each patient’s propensity score was calculated, allowing selectively matched subgroups of 40 patients each. Initial surgery included coronary artery bypass grafting in 30 patients, aortic valve replacement in 7 patients and mitral valve reconstruction in 3 patients in each group. Follow-up was 4 ± 2 years and was 100% complete.
Results: Postoperative chest tube drainage (163 ± 214 vs. 562 ± 332 ml/24 h, p = 0.02) and incidence of early permanent neurologic deficit (0 vs. 13%, p = 0.04) was lower in patients with Redo-TAVI and there was a trend towards improved 30-day survival (p = 0.06). Also we detected a decreased ventilation time (p = 0.04) and lower transfusion rate of allogenic blood products (p ≤ 0.05) in the Redo-TAVI group. At late follow up differences regarding incidence of major adverse events, including death and permanent neurologic deficits (25% vs. 43%, p = 0.01) statistically supported early postoperative findings.
Conclusion: The encouraging results regarding early and long-term outcomes following TAVI in patients with previous cardiac surgery show, that this evolving approach may be particularly beneficial in this patient cohort.
Device-related infections in recipients of left ventricular assist devices (LVAD) have been recognized as a major source of morbidity and mortality. They require a high level of diagnostic effort as part of the overall burden resulting from infectious complications in LVAD recipients. We present a multi-allergic patient who was treated for persistent sterile intrathoracic abscess formation and pericardial empyema following minimally invasive LVAD implantation including use of a sheet of e-polytetrafluoroethylene (ePTFE) membrane to restore pericardial integrity. Sterile abscess formation and pericardial empyema recurred after surgical removal until the ePTFE membrane was removed, suggesting that in disposed patients, ePTFE may be related to sterile abscess formation or sterile empyema.
BACKGROUND: Polyclonal anti-thymocyte globulins (ATGs) are immunosuppressive drugs widely used in induction of immunosuppression and treatment of acute rejection after solid organ transplantation. We have previously demonstrated that ATGs bind to endothelial cells in vitro, and are able to modulate ECs. The aim of this study was to investigate the binding of ATGs to endothelial cells under in vivo conditions.
MATERIAL AND METHODS: Muscle biopsies from extremities of cynomolgus monkeys were obtained after ischemia/reperfusion at 4°C. ATGs (Thymoglobulin, Sanofi-Aventis, France; 1 mg/kg) were added to the blood 30 min prior to the reperfusion. Biopsies (n=10) of patients undergoing heart transplantation and preoperatively treated with ATGs (Thymoglobulin, Sanofi-Aventis, France; 1.5 mg/kg) as induction therapy were also analyzed 6 hours and 7 days after induction. Binding of ATGs to ECs was analyzed with an anti-rabbit IgG antibody by means of immunohistochemistry.
RESULTS: Binding of ATGs to endothelial cells could be demonstrated in vivo in our animal experiments 4 hours after reperfusion, as well as in the clinical biopsies 6 hours after induction of immunosuppression in heart transplant patients, showing a preferred localization in post-capillary veins. No expression of ATGs on the endothelial surface could be observed after 7 days, suggesting that ATGs may be washed out from the endothelial surface in a time-dependent manner.
CONCLUSIONS: Our results show that ATGs are able to bind to endothelial cells in an experimental model and in clinical practice, supporting preconditioning strategies with ATGs in solid organ transplantation.
Patients with risks of ischemic injury, e.g. during circulatory arrest in cardiac surgery, or after resuscitation are subjected to therapeutic hypothermia. For aortic surgery, the body is traditionally cooled down to 18 °C and then rewarmed to body temperature. The role of hypothermia and the subsequent rewarming process on leukocyte-endothelial interactions and expression of junctional-adhesion-molecules is not clarified yet. Thus, we investigated in an in-vitro model the influence of temperature modulation during activation and transendothelial migration of leukocytes through human endothelial cells. Additionally, we investigated the expression of JAMs in the rewarming phase. Exposure to low temperatures alone during transmigration scarcely affects leukocyte extravasation, whereas hypothermia during treatment and transendothelial migration improves leukocyte-endothelial interactions. Rewarming causes a significant up-regulation of transmigration with falling temperatures. JAM-A is significantly modulated during rewarming. Our data suggest that transendothelial migration of leukocytes is not only modulated by cell-activation itself. Activation temperatures and the rewarming process are essential. Continued hypothermia significantly inhibits transendothelial migration, whereas the rewarming process enhances transmigration strongly. The expression of JAMs, especially JAM-A, is strongly modulated during the rewarming process. Endothelial protection prior to warm reperfusion and mild hypothermic conditions reducing the difference between hypothermia and rewarming temperatures should be considered.
Background: Ischemia-reperfusion injury (IRI) is a major challenge in liver transplantation. The mitochondrial pathway plays a pivotal role in hepatic IRI. Levosimendan, a calcium channel sensitizer, was shown to attenuate apoptosis after IRI in animal livers. The aim of this study was to investigate the effect of levosimendan on apoptosis in human hepatocytes.
Methods: Primary human hepatocytes were either exposed to hypoxia or cultured under normoxic conditions. After the hypoxic phase, reoxygenation was implemented and cells were treated with different concentrations of levosimendan (10ng/ml, 100ng/ml, 1000ng/ml). The overall metabolic activity of the cells was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and aspartate aminotransferase (AST) levels were determined in order to quantify hepatic injury. Fluorescence-activated cell sorting (FACS) analysis was applied to measure necrosis and apoptosis. Finally, Western blotting was performed to analyze apoptotic pathway proteins.
Results: Administration of levosimendan during reperfusion increases the metabolic activity of human hepatocytes and decreases AST levels. Moreover, apoptosis after IRI is reduced in treated vs. untreated hepatocytes, and levosimendan prevents down-regulation of the anti-apoptotic protein Bcl-2 as well as up-regulation of the pro-apoptotic protein BAX.
Conclusion: The present study suggests a protective effect of levosimendan on human hepatocytes. Our findings suggest that treatment with levosimendan during reperfusion attenuates apoptosis of human hepatocytes by influencing BAX and Bcl-2 levels.
Background: The aim of this study was to evaluate the longer-term results of bicuspid aortic valve (BAV) repair with or without aortic root replacement. Methods: From 1999 to 2017, 142 patients with or without aortic root dilatation who underwent repair of a regurgitant BAV were included in the study. Ninety-four patients underwent isolated BAV repair (Group 1; median age 43 years) and 48 patients underwent valve-sparing aortic root replacement plus BAV repair (aortic valve reimplantation—Group 2; median age 48 years). Median clinical follow-up time was 5.9 years (range 0.5–15) in Group 1 and 3 years (range 0.5–16) in Group 2, respectively. Results: In-hospital mortality was 1% in Group 1, and 2% in Group 2 (p = .6). The 5- and 10-year survival was 93 ± 2.9% and 81 ± 5.8% in Group 1 and 96 ± 3.1% and 96 ± 3.1% in Group 2, respectively (p = .31). Eleven patients of Group 1 (1.7%/patient-year) and five patients of Group 2 (2.2%/patient-year) underwent reoperation of the aortic valve (p = .5). The 5- and 10-year freedom from reoperation were 93.0 ± 2.1% and 77.1 ± 7.1% in Group 1 and 93.0 ± 5.0% and 76.7 ± 9.6% in Group 2 (p = .83), respectively. At the latest follow-up, only two patients of Group 1 and 1 patient of Group 2 had AV regurgitation = 2° (p = .7). The cumulative linearized incidence of all valve-related complications (bleeding, stroke, endocarditis, and reoperation) was 2.9%/patient-year in Group 1% and 4%/patient-year in Group 2, respectively (p = .6). Conclusions: Isolated BAV repair and combined aortic valve reimplantation plus BAV repair provide good clinical longer-term outcomes with relatively low reoperation rate and durable valve function.