Wolfgang Konertz

Charité Universitätsmedizin Berlin, Berlín, Berlin, Germany

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Publications (320)703.63 Total impact

  • S. Holinski · K. Zhigalov · T. Christ · W. Konertz

    No preview · Article · Jan 2016 · The Thoracic and Cardiovascular Surgeon
  • T. Christ · B. Claus · N. Woythal · S. Dushe · W. Konertz · H. Grubitzsch

    No preview · Article · Jan 2016 · The Thoracic and Cardiovascular Surgeon
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    ABSTRACT: A retrospective long-term evaluation of the St. Jude Toronto stentless bioprosthesis in patients aged 60 years or younger. From 1994 to 1997, 50 patients underwent aortic valve replacement with the prosthesis. Patients mean age at surgery was 54.5±6.3 years. Follow-up data were acquired by patient file research and telephone interviews. Morbidity and mortality were evaluated with time-to-event analyses using the Kaplan-Meier-method. The log-rank test was used to determine influencing factors for long-term survival and reoperation. Mean follow-up was 13.5±6.3 years with a total follow-up of 661.8 patient-years and a maximum of 20.0 years. Follow-up was 97.8% complete. Associated procedures were performed in 12 patients (24%), including coronary artery bypass grafting, mitral valve replacement and replacement of the ascending aorta. Freedom from reoperation at 10 and 15 years was 76.0±6.7% and 44.1±8.9%, respectively. Reoperations (n=26) started 4.4 years after implantation and were necessary due to: valve degeneration with regurgitation in 79.2% and stenosis in 12.5%, endocarditis in 4.2% and sinus valsalva aneurysm in 4.2% of the cases. The log-rank test revealed that only body-mass-index>25 lowered freedom-from-reoperation, while renal dysfunction, diabetes mellitus and arterial hypertension were not. Overall long-term survival at 10 and 20 years was 82.3±5.7% and 49.9±8.9%, respectively. In younger patients the Toronto-bioprosthesis provided reliable long-term survival despite limited durability.
    No preview · Article · Sep 2015 · Heart Surgery Forum
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    Torsten Christ · Pascal Dohmen · Michael Laule · Karl Stangl · Wolfgang Konertz

    Full-text · Article · Jul 2015
  • Sebastian Holinski · Gerd Hausdorf · Wolfgang Konertz
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    ABSTRACT: We present a case of a young man, who underwent heterotopic heart transplantation 20 years ago, when he was 6 months old. The baby suffered from severe intractable cardiomyopathy. In this desperate situation only a miniature, compromised donor heart became available. Today, the young man is fully active under minimal immunosuppression. His surgical course is reviewed and described. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
    No preview · Article · Feb 2015 · European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery
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    Sebastian Holinski · Sören Jessen · Konrad Neumann · Wolfgang Konertz
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    ABSTRACT: Objective: We evaluated the predictive power of the EuroSCORE, EuroSCORE II and Society of Thoracic Surgeons (STS) score for isolated redo aortic valve replacement.Materials and Methods: 78 consecutive patients underwent the aforementioned procedure mainly with a stentless valve prosthesis at our institution. Observed mortality was compared to the predicted mortality, Receiver Operating Characteristics (ROC) curves were calculated and the area under the curve (AUC) analyzed.Result: Observed mortality was 11.5%. EuroSCORE and EuroScore II predicted a mortality of 28.2 ± 21.6% (p <0.001) and 10.2 ± 11.8% (p = 0.75), respectively. AUC of the EuroSCORE was 0.74 (95% CI: 0.62-0.83), p = 0.009 and of the EuroSCORE II 0.86 (95% CI: 0.76-0.93), p <0.0001. Optimal Youden index of the EuroSCORE II was 0.59 refering to a predicted mortality of 9.9% (sensitivity: 77.8% and specificity: 81.2%). Predicted mortality of STS score was 17.8 ± 10.6% (p = 0.08) and AUC was 0.64 (95% CI: 0.53-0.75), p = 0.06.Conclusion: EuroSCORE II calculation was not only superior to EuroSCORE and STS score but led to a very realistic mortality prediction for this special procedure at our institution. A EuroSCORE II greater 10 should encourage to consider an alternative treatment.
    Preview · Article · Feb 2015 · Annals of thoracic and cardiovascular surgery: official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia
  • S. Holinski · K. Zhigalov · W. Konertz

    No preview · Article · Jan 2015 · The Thoracic and Cardiovascular Surgeon
  • S. Holinski · K. Zhigalov · W. Konertz

    No preview · Article · Jan 2015 · The Thoracic and Cardiovascular Surgeon
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    ABSTRACT: Objectives Stentless aortic valve replacements show improved hemodynamics due to larger orifice area and lower transvalvular gradients in short and mid-term follow-up. Hemodynamic long-term behavior and the adaptation of the left ventricle as well as valve-durability in patients aged ¿60 years remains unclear.Methods7 to 16 years after aortic valve replacement, 54 patients (mean age at operation 53.1¿±¿years) received echocardiography and clinical examination. Mean follow-up time was 10.8¿±¿2.2 years. Evaluated were NYHA class, transvalvular gradients, estimated aortic valve orifice area, degree of aortic valve insufficiency, left ventricular mass and function.ResultsAt follow-up only one patient presented with NYHA class III. All other patients were in NYHA class I or II. Maximum and mean pressure gradients of the prostheses were 16.3¿±¿7.4 mmHg and 9.1¿±¿4.2 mmHg, respectively. Compared to echocardiography at discharge the mean pressure gradients dropped 18.0% (2.0¿±¿0.9 mmHg) and stayed stable until 14 years after the operation. Only 5 patients showed relevant regurgitation (at 13¿16 years after valve replacement), 49 showed no or trivial regurgitation. Left ventricular mass had decreased 26.5% (107.9¿±¿18.5 g). Left ventricular ejection fraction (LVEF) had increased in most patients and decreased in only one. For patients with preoperatively impaired left ventricular function an increase of LVEF of 13.1¿±¿3.1% was seen.Conclusion Porcine stentless aortic valves provide excellent hemodynamic long-term results without significant rise of transvalvular pressure gradients or relevant insufficiencies until 14 years after implantation, leading to sustained decrease of left ventricular mass and improvement of left ventricular function.
    Full-text · Article · Dec 2014 · Journal of Cardiothoracic Surgery
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    ABSTRACT: Background Tissue engineering (TE) is a promising approach to overcome problems associated with biological heart valve prosthesis. Currently several animal models are used to advance this method. The rat subdermal model is uncomplicated and widely used, but its suitability for TE has not yet been shown. Material/Methods Using the rat subdermal model we implanted two decellularized porcine aortic wall specimens (of which one was endothelialized) and one native porcine aortic wall specimen in 30 Lewis rats, respectively. Endothelial cells (EC) were harvested from the rat jugular veins. After explantation Hematoxylin/Eosin-staining, CD-68-positive cell staining, fibroblast-staining and Von-Willebrand factor staining were performed. Results All animals survived without complications. Endothelialization was confirmed to be effective by Giemsa staining. Histological evaluation of specimens in Hematoxylin/Eosin staining showed significant decrease (p<0.05) of inflammatory reaction (confirmed by CD-68-positive cell staining) after decellularization. All specimens showed strongest inflammatory reactions at areas of destroyed extracellular matrix. Fibroblasts could be detected in all specimens, with strongest infiltration in decellularized specimens (p<0.05). Surrounding endothelialized specimens had no monolayer of endothelial cells, but a higher density of blood vessels occurred (p<0.05). Conclusions The subdermal model provides excellent contact of host tissue with implanted specimens leading to rapid cellular infiltration; therefore, we could ascertain reduced inflammatory response to decellularized tissue. Due to the subdermal position, an absence of blood stream and mechanical stress occurs, which influences cellular repopulation; therefore, endothelialization did not lead to an EC monolayer, but rather to increased vascularization. Thus, the model appears ideal for investigating basic biological compatibility, but further questions must be researched using other models.
    Full-text · Article · Dec 2014
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    ABSTRACT: Objectives: This study examined the outcomes of surgery for active prosthetic valve endocarditis in a recent decade, with special interest in preoperative treatment and predictors for early and late events. Methods: From 2000 to 2010, a cohort of 149 consecutive patients (mean age, 64±13.9 years; 72% were male) underwent redo-surgery for prosthetic valve endocarditis and were reviewed regarding early (≤60 days) and late (>60 days) events (death, reinfection, reoperation). Kaplan-Meier survival curves and Cox regression analysis were used to investigate the impact of preoperative intervals and predictors for events, respectively. Results: Preoperative status was critical (European System for Cardiac Operative Risk Evaluation>20%) in 121 patients (81.2%). Staphylococci were the most common infecting microorganisms (27.5%). The median interval between onset of symptoms and diagnosis and between diagnosis and operation was 2 days (interquartile range, 1-5) and 8 days (interquartile range, 2-23), respectively. Operative mortality (≤30 days) was 12.8%. Mean follow-up was 4±2.9 years. In 53 patients, 47 early (24 deaths, 14 recurrences, 9 reoperations) and 22 late events (11 deaths, 9 recurrences, 2 reoperations) occurred. Overall and event-free survivals at 10 years were 75%±3.8% and 64%±4.0%, respectively. Freedom from recurrent infection and reoperation at 10 years were 81%±3.6% and 91%±2.6%, respectively. In multivariate Cox regression, mechanical circulatory support, prolongation between onset of symptoms and diagnosis more than 30 days, and preoperative presence of renal failure predicted early events, and double valve replacement predicted late events. Conclusions: Cardiac and renal function, need for double valve replacement, and preoperative treatment predicted outcomes. A prolonged interval in which patients were left untreated while symptomatic, but not prolongation of preoperative antibiotic treatment, increased risk.
    No preview · Article · May 2014 · Journal of Thoracic and Cardiovascular Surgery
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    ABSTRACT: Background Eprosartan is an angiotensin II receptor antagonist used as an antihypertensive. We sought to evaluate the regional effect of Eprosartan on postinfarct ventricular remodeling and myocardial function in an isolated swine working heart model of ischemia-reperfusion injury. Material/Methods 22 swine hearts were perfused with the Langendorff perfusion apparatus under standard experimental conditions. Myocardial ischemia was induced by a 10-min left anterior descending artery ligation. Hearts were reperfused with either saline (control group, n=11), or Eprosartan (treatment group, n=11). Left ventricular pressure (LVP) and regional heart parameters such as intramyocardial pressure (IMP), wall thickening rate (WTh), and pressure-length-loops (PLL) were measured at baseline and after 30 min of reperfusion. Results Measured parameters were statistically similar between the 2 groups at baseline. The administration of Eprosartan led to a significantly better recovery of IMP and WTh: 44.4±2.5 mmHg vs. 51.2±3.3 mmHg, p<0.001 and 3.8±0.4 μm vs. 4.4±0.3 μm, p=0.001, respectively. PLL were also significantly higher in the treatment group following reperfusion (21694±3259 units vs. 31267±3429 units, p<0.01). There was no difference in the LVP response to Eprosartan versus controls (63.6±3.0 mmHg vs. 62.5±3.1 mmHg, p=0.400). Conclusions Pre-treatment with Eprosartan is associated with a significant improvement in regional cardiac function under ischemic conditions. Pharmacological treatment with eprosartan may exert a direct cardioprotective effect on ischemic myocardium.
    Full-text · Article · Apr 2014
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    ABSTRACT: Background Eprosartan is an angiotensin II receptor antagonist used as an antihypertensive. We sought to evaluate the regional effect of Eprosartan on postinfarct ventricular remodeling and myocardial function in an isolated swine working heart model of ischemia-reperfusion injury. Material and Methods 22 swine hearts were perfused with the Langendorff perfusion apparatus under standard experimental conditions. Myocardial ischemia was induced by a 10-min left anterior descending artery ligation. Hearts were reperfused with either saline (control group, n=11), or Eprosartan (treatment group, n=11). Left ventricular pressure (LVP) and regional heart parameters such as intramyocardial pressure (IMP), wall thickening rate (WTh), and pressure-length-loops (PLL) were measured at baseline and after 30 min of reperfusion. Results Measured parameters were statistically similar between the 2 groups at baseline. The administration of Eprosartan led to a significantly better recovery of IMP and WTh: 44.4±2.5 mmHg vs. 51.2±3.3 mmHg, p<0.001 and 3.8±0.4 µm vs. 4.4±0.3 µm, p=0.001, respectively. PLL were also significantly higher in the treatment group following reperfusion (21694±3259 units vs. 31267±3429 units, p<0.01). There was no difference in the LVP response to Eprosartan versus controls (63.6±3.0 mmHg vs. 62.5±3.1 mmHg, p=0.400). Conclusions Pre-treatment with Eprosartan is associated with a significant improvement in regional cardiac function under ischemic conditions. Pharmacological treatment with eprosartan may exert a direct cardioprotective effect on ischemic myocardium
    Full-text · Article · Apr 2014

  • No preview · Article · Feb 2014 · The Thoracic and Cardiovascular Surgeon
  • S. Hoffmann · J. Linneweber · B. Claus · W. Konertz

    No preview · Article · Feb 2014 · The Thoracic and Cardiovascular Surgeon
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    ABSTRACT: Background In the past, successful use of decellularized xenogenic tissue was shown in the pulmonary circulation. This study, however, evaluates a newly developed decellularized equine pericardial patch under high pressure circumstances. Material/Methods Seven decellularized equine pericardial scaffolds were implanted into the descending aorta of the juvenile sheep. The implanted patches were oversized to evaluate the durability of the decellularized tissue under high surface tension (Law of Laplace). After 4 months of implantation, all decellularized patches were inspected by gross examination, light microscopy (H&E, Serius red, Gomori, Weigert, and von Kossa straining), and immunohistochemical staining. Results The juvenile sheep showed fast recovery after surgery. There was no mortality during follow-up. At explantation, only limited adhesion was seen at the surgical site. Gross examination showed a smooth and pliable surface without degeneration, as well as absence of aneurysmatic dilatation. Light microscopy showed a well preserved extracellular scaffold with a monolayer of endothelial cells covering the luminal side of the patch. On the outside part of the patch, a well developed neo-vascularization was seen. Host fibroblasts were seen in all layers of the scaffolds. There was no evidence for structural deterioration or calcification of the decellularized equine pericardial scaffolds. Conclusions In the juvenile sheep, decellularized equine tissue showed no structural deterioration, but regeneration and remodeling processes at systemic circulation.
    Full-text · Article · Jan 2014
  • Joerg Linneweber · Benjamin Claus · Wolfgang Konertz

    No preview · Article · Jan 2014 · Cardiology
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    ABSTRACT: Repeat aortic valve replacement (AVR) after freestanding homograft root replacement with reimplantation of the coronary arteries is challenging and risky, especially in patients with major homograft wall calcifications. Although new transcatheter techniques for AVR may offer an alternative in structurally degenerated homografts, they are not suitable to treat endocarditis. Here, the case is reported of successful treatment of bacterial endocarditis within a totally calcified homograft after aortic root replacement by combining conventional surgery and transcatheter techniques.
    No preview · Article · Sep 2013 · The Journal of heart valve disease
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    Torsten Christ · Herko Grubitzsch · Benjamin Claus · Wolfgang Konertz
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    ABSTRACT: Background Stentless aortic valve replacement (SAVR) became a common surgical procedure to treat aortic valve disease, as it offers larger orifice area and improved hemodynamics. The aim of our single-centre retrospective study was to assess long term results of first generation stentless aortic valves in young patients, where mechanical prostheses are considered first line therapy. Methods From 1993 to 2001, 188 (149 male and 39 female) patients (≤60 years) underwent SAVR. Indications were in 63.3% stenosis or mixed lesions and in 36.7% isolated regurgitation. Mean age of patients at surgery was 53.1 ± 7.1 years. Associated procedures were performed in 60 patients (31.9%). Follow-up data were acquired through telephone interviews. Follow-up was 90.4% complete at a mean of 8.8 ± 4.7 years. Total follow-up was 1657.6 patient-years with a maximum of 17 years. Results Overall hospital mortality was 3.2% (2.5% for isolated SAVR). Overall actuarial survival-rate at 10/15 years and freedom from reoperation at 10/14 years were 73.0% ± 3.5%/ 55.8% ± 5.4% and 81.0% ± 3.4%/ 58.0% ± 7.5%, respectively. For isolated SAVR, actuarial survival at 10/15 years and freedom from reoperation at 10/14 years were 70.1% ± 4.4%/ 64.1% ± 4.8% and 83.1% ± 4.0%/ 52.9% ± 9.0%, respectively. Reoperation was performed in 42 patients (22.3%) due to structural valve deterioration and endocarditis. Age (≤50 years) and associated procedures did not significantly lower survival and freedom from reoperation, however, small prosthesis sizes (≤25 mm) did. Conclusion In patients aged 60 and younger, SAVR provides reliable long-term results especially for larger aortic valves.
    Full-text · Article · Apr 2013 · Journal of Cardiothoracic Surgery
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    ABSTRACT: This clinical study was performed to investigate the patency rate of endothelial cell-seeded small-diameter expanded polytetrafluoroethylene grafts during coronary artery bypass surgery. Between September 1995 and December 1998, 14 patients (median age: 71 years, range: 61-79 years) received 21 endothelial cell-seeded small-diameter grafts. In all, 43% of the performed implantations were reoperations. Endothelial cells were harvested from a forearm vein, cultured and characterized in the laboratory until a sufficient number was available. After in vitro seeding, the grafts were allowed to mature for another 10 days, prior to implantation. Graft patency was investigated with angiography, angioscopy, and intravascular ultrasonography during follow-up. Cumulative data represented 58 patients' years and was 100% complete. The seeded autologous vascular endothelial cell density was 1.05 × 10(5) ± 0.12 × 10(5) cells/cm(2) with a cell viability of 95.5 ± 1.5%. Operative mortality was 7.1% (one patient). Patency rate at discharge was 95.2%, and at a mean follow-up of 27 months was 90.5%. The proven patency rate at up to 72 months was at least 50.0%, as five patients refused angiographic evaluation. None of these five patients suffered from angina pectoris and so the best scenario would have shown a patency rate of 85.7%. Angioscopy and intravascular ultrasonography showed absence of atheroma or stenosis in the investigated patent grafts. Autologous vascular endothelial cell seeding improves patency rate of small-caliber expanded polytetrafluoroethylene grafts in patients without suitable autologous graft material.
    Full-text · Article · Feb 2013 · Journal of Tissue Engineering

Publication Stats

4k Citations
703.63 Total Impact Points

Institutions

  • 1996-2015
    • Charité Universitätsmedizin Berlin
      • • Department of Cardiovascular Surgery
      • • Department of Anesthesiology and Operative Intensive Care Medicine
      Berlín, Berlin, Germany
  • 1995-2012
    • Humboldt-Universität zu Berlin
      • Department of Biology
      Berlín, Berlin, Germany
  • 2001-2005
    • Freie Universität Berlin
      Berlín, Berlin, Germany
  • 2004
    • New York Presbyterian Hospital
      New York, New York, United States
  • 2003
    • Humboldt State University
      ACV, California, United States
    • Tokai University
      • Department of Cardiovascular Surgery
      Hiratuka, Kanagawa, Japan
  • 1992-1994
    • University of Münster
      Muenster, North Rhine-Westphalia, Germany
  • 1980-1993
    • Christian-Albrechts-Universität zu Kiel
      Kiel, Schleswig-Holstein, Germany