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    <title>Klieverik, L.M.A.</title>
    <link>http://repub.eur.nl/res/aut/13906/</link>
    <description>List of Publications</description>
    <language>en</language>
    <image>
      <url>http://repub.eur.nl/static-eur/img/logo.png</url>
      <title>RePub, Erasmus University Rotterdam</title>
      <link>http://repub.eur.nl</link>
    </image>
    <item>
      <title>Re-operations for aortic allograft root failure: Experience from a 21-year single-center prospective follow-up study (Article)</title>
      <link>http://repub.eur.nl/res/pub/26058/</link>
      <pubDate>2011-07-01T00:00:00Z</pubDate>
      <description>Objective: The study aims to report results of re-operations after aortic allograft root implantation. Methods: All consecutive patients in our prospective allograft database, who underwent aortic allograft root implantation, were selected for analysis, and additional information for patients who subsequently underwent re-operation was obtained from hospital records. Results: From 1989 to 2009, 262 aortic allograft root implantations were performed. Thirty-day mortality was 5.7%. During follow-up, 69 patients died. The actuarial survival was 77.0% (95% confidence interval (CI) 71-83%) after 10 years, and 65.1% (95% CI 57-74%) after 14 years. A total of 52 patients required re-operation. The actuarial freedom from allograft re-operation was 82.9% (Standard Error (SE) 2.9%) after 10 years and 55.7% (SE 5.7%) after 14 years. The actuarial median time to re-operation was 14.8 years. The indications for re-operation were structural valve dysfunction in 46 patients, endocarditis in two patients and non-structural valve dysfunction in four patients. The re-operations included 23 aortic valve replacements (mechanical prostheses 20 and bioprostheses 3), 27 aortic root replacements (mechanical conduits 21, aortic allografts five, and biological conduit one), one trans-apical valve implantation and one primary closure of a false aneurysm. The additional procedures were mitral valve repair (N=5), mitral valve replacement (N=1), ascending aortic replacement (N=5), and coronary artery bypass grafting (CABG) (N=4; in two patients unforeseen). Thirty-day mortality after re-operation occurred in two patients (3.9%). Five patients died during follow-up. The survival after re-operation was 87.1% (SE 5.5%) after 1 year and 79.3% (SE 7.4%) after 9 years. Conclusions: Re-operations after aortic allograft root implantation will be required in a substantial and growing number of patients. These re-operations, although technically demanding, can be performed with satisfying results. </description>
    </item> <item>
      <title>Aortic root reoperations after pulmonary autograft implantation (Article)</title>
      <link>http://repub.eur.nl/res/pub/21751/</link>
      <pubDate>2010-12-01T00:00:00Z</pubDate>
      <description>Objective: To report the results of aortic root reoperations after pulmonary autograft implantation. Methods: All consecutive patients in our prospective Ross research database were selected for analysis, and additional information for patients requiring reoperation was obtained from the hospital records. Results: From 1988 to 2009, 155 pulmonary autograft operations were performed. During this period, 41 patients required reoperation for aortic root dilatation and/or autograft valve insufficiency, in 8 patients combined with pulmonary allograft dysfunction. The freedom from autograft reoperation rate was 86% (standard error, 3.3%) after 10 years and 52% (standard error, 6.6%) after 15 years. The median interval to reoperation was 15.3 years. During reoperation, 39 patients underwent aortic root replacement (mechanical conduit, 31; stentless root, 2; allograft, 3; and valve sparing, 3), and 2 patients underwent valve replacement. In 8 patients this was combined with pulmonary allograft replacement. The technical difficulties encountered included bleeding at the sternal re-entry in 5 patients. No 30-day mortality occurred. The postoperative complications included reexploration for persistent blood loss in 3 patients and cerebrovascular accident in 3 patients. Two patients died during the follow-up period. The survival rate after reoperation was 94% (standard error, 4.1%) at 5 years. Conclusions: An increasing number of patients requires reoperation after pulmonary autograft implantation. These reoperations can be done with very low mortality and morbidity and excellent follow-up results.</description>
    </item> <item>
      <title>Surgical Treatment of Active Native Aortic Valve Endocarditis With Allografts and Mechanical Prostheses (Article)</title>
      <link>http://repub.eur.nl/res/pub/24283/</link>
      <pubDate>2009-12-01T00:00:00Z</pubDate>
      <description>Background: Surgical intervention for persistent active native aortic valve endocarditis (NVE) remains challenging. We analyzed our combined experience with allografts and mechanical prostheses (MP) in NVE operations. Methods: Between 1980 and 2002, 138 patients (81% males) underwent aortic valve replacement for NVE in 2 centers (106 allografts; 32 MPs). Perioperative characteristics and early and late morbidity and mortality were analyzed. Results: Mean age was 47 years (range, 14 to 76 years), and 34% required emergency surgery. Abscess rate was 38% for allografts vs 18% for MPs. Concomitant mitral valve replacement was required in 38% MP patients and in 5% allograft patients. Hospital mortality was 8% (n = 11; p = 0.25): 10 allograft patients (9%) and 1 MP patient (3%). During a mean 8-year follow-up (range, 0 to 25 years) 33 patients died: 22 allograft (24%) and 11 MP patients (21%; p = 0.14). Survival at 15 years was 59% ± 6% for allograft patients and 66% ± 9% for MP patients (p = 0.68). Late recurrent endocarditis developed in 6 allograft patients and 1 MP patient (p = 0.29). Overall 15-year freedom from reoperation was 76% ± 9% for allografts and 93% ± 6% for MPs (p = 0.02). Conclusions: Mechanical prostheses have comparable rates of midterm survival and freedom from recurrent infection. However, this is in combination with extensive excision of destructive tissue in a specific patient subset. Allograft reoperation rates increase with time. The importance of the mechanical prosthesis in NVE might be established in the coming years. </description>
    </item> <item>
      <title>The Ross procedure: A systematic review and meta-analysis (Article)</title>
      <link>http://repub.eur.nl/res/pub/19343/</link>
      <pubDate>2009-01-20T00:00:00Z</pubDate>
      <description>Background - Reports on outcome after the Ross procedure are limited by small study size and show variable durability results. A systematic review of evidence on outcome after the Ross procedure may improve insight into outcome and potential determinants. Methods and Results - A systematic review of reports published from January 2000 to January 2008 on outcome after the Ross procedure was undertaken. Thirty-nine articles meeting the inclusion criteria were allocated to 3 categories: (1) consecutive series, (2) adult patient series, and (3) pediatric patient series. With the use of an inverse variance approach, pooled morbidity and mortality rates were obtained. Pooled early mortality for consecutive, adult, and pediatric patients series was 3.0% (95% confidence interval [CI], 1.8 to 4.9), 3.2% (95% CI, 1.5 to 6.6), and 4.2% (95% CI, 1.4 to 11.5). Autograft deterioration rates were 1.15% (95% CI, 1.06 to 2.06), 0.78% (95% CI, 0.43 to 1.40), and 1.38%/patient-year (95% CI, 0.68 to 2.80), respectively, and for right ventricular outflow tract conduit were 0.91% (95% CI, 0.56 to 1.47), 0.55% (95% CI, 0.26 to 1.17), and 1.60%/patient-year (95% CI, 0.84 to 3.05), respectively. For studies with mean patient age &gt;18 years versus mean patient age ≤ 18 years, pooled autograft and right ventricular outflow tract deterioration rates were 1.14% (95% CI, 0.83 to 1.57) versus 1.69% (95% CI, 1.02 to 2.79) and 0.65% (95% CI, 0.41 to 1.02) versus 1.66%/patient-year (95% CI, 0.98 to 2.82), respectively. Conclusions - The Ross procedure provides satisfactory results for both children and young adults. Durability limitations become apparent by the end of the first postoperative decade, in particular in younger patients.</description>
    </item> <item>
      <title>Is the Ross procedure really a Trojan horse: Reply (Article)</title>
      <link>http://repub.eur.nl/res/pub/15204/</link>
      <pubDate>2008-09-01T00:00:00Z</pubDate>
      <description></description>
    </item> <item>
      <title>Long-term follow-up after repair of Ebstein's anomaly (Article)</title>
      <link>http://repub.eur.nl/res/pub/30210/</link>
      <pubDate>2008-07-01T00:00:00Z</pubDate>
      <description>Objective: We studied the long-term results of vertical plication repair of Ebstein's anomaly according to Carpentier. Methods: Between 1988 and 2007, 28 patients (mean age 28.8 ± 15.7 years, range 4-58 years) underwent vertical plication repair of Ebstein's anomaly. At operation the anomaly was classified according to Carpentier. In three patients (11%) a cavopulmonary shunt was added at the repair on the indication of impaired right ventricular function. Results: There was no operative mortality. Early mortality was 3.6% (one patient). Actuarial survival and actuarial freedom from reoperation at 19 years were 96% (95% CI; 96-97%) and 72% (95% CI; 53-92%), respectively. Six patients required reoperation, with a successful re-repair in three patients. Mean duration of follow-up was 10.7 ± 6.5 years. One year postoperatively, tricuspid incompetence had decreased significantly (p &lt; 0.001), as had New York Heart Association (NYHA) functional class (p &lt; 0.001). In addition, exercise tolerance had increased (70 ± 19% to 92 ± 9% of predicted values, p &lt; 0.05). Both tricuspid function and NYHA functional class remained essentially unchanged at the end of follow-up, indicating durable haemodynamic and functional results. Conclusion: This study demonstrates favourable long-term results following vertical plication repair of Ebstein's anomaly with low mortality, acceptable morbidity and good haemodynamic and functional results. </description>
    </item> <item>
      <title>Autograft or allograft aortic valve replacement in young adult patients with congenital aortic valve disease (Article)</title>
      <link>http://repub.eur.nl/res/pub/29443/</link>
      <pubDate>2008-06-01T00:00:00Z</pubDate>
      <description>Aims: We analysed the outcome of young adults with congenital aortic valve disease who underwent allograft or autograft aortic valve or root replacement in our institution and evaluated whether there is a preference for either valve substitute. Methods and results: Between 1987 and 2007, 169 consecutive patients with congenital aortic valve disease aged 16-55, participating in our ongoing prospective follow-up study, underwent 63 autograft and 106 allograft aortic valve replacements (AVRs). Mean age was 35 years (SD 10.8), 71% were males. Aetiology was 71% bicuspid valve, 14% other congenital, and 15% BV endocarditis. Twenty-two percent underwent previous cardiac surgery; 11% had an ascending aorta aneurysm. Two patients died in hospital. During follow-up six more patients died and 45 patients required valve-related re-operations. Thirteen-year survival was 97% for autograft and 93% for allograft recipients, 13 year freedom from valve-related re-operation was 63% for autograft and 69% for allograft patients. Conclusion: In patients with congenital aortic valve disease, autograft and allograft AVR show comparable satisfactory early and long-term results, with the increasing re-operation risk in the second decade after operation remaining a major concern. </description>
    </item> <item>
      <title>Aortic Valve Replacement in Young Adults (Doctoral Thesis)</title>
      <link>http://repub.eur.nl/res/pub/10778/</link>
      <pubDate>2007-12-12T00:00:00Z</pubDate>
      <description>Worldwide the incidence and burden of heart valve disease is increasing due to aging
of the world population and the problem of rheumatic cardiac disease in developing
countries and in parts of the population in the developed world.1 Between 2007
and 2050 the world population will increase from 6.5 to 9.1 billion inhabitants.1
Furthermore, the annual number of patients requiring heart valve replacement
is estimated to triple from approximately 290,000 in 2003, to over 850,000 by
2050.2
In the Netherlands cardiovascular disease is the leading cause of death. According
to the annual report of the Dutch Heart Association, 308.828 patients required
admission due to cardiovascular disease in the Netherlands in 2004 of which 7286
patients were admitted due to rheumatic heart disease or valve disease (2.4%).
Subsequently, 1449 patients died of heart valve disease (3.2%).3 Furthermore,
approximately 3000 patients require valve replacement due to aortic valve disease
per year in the Netherlands.</description>
    </item> <item>
      <title>The Ross operation: A Trojan horse? (Article)</title>
      <link>http://repub.eur.nl/res/pub/35749/</link>
      <pubDate>2007-08-01T00:00:00Z</pubDate>
      <description>Aims: The Ross operation is the operation of choice for children who require aortic valve replacement (AVR) and may also provide a good option in selected adult patients. Although the autograft does not require anticoagulation and has a superior haemodynamic profile, concern regarding autograft and allograft longevity has risen. In this light, we report the 13-year results of our prospective autograft cohort study. Methods and results: Between 1988 and 2005, 146 consecutive patients underwent AVR with a pulmonary autograft at Erasmus Medical Center Rotterdam. Mean age was 22 years (SD 13; range 4 months-52 years), 66% were male. Hospital mortality was 2.7% (N = 4); during follow-up four more patients died. Thirteen-year survival was 94 ± 2%. Over time, 22 patients required autograft reoperation for progressive neo-aortic root dilatation. In addition, eight patients required allograft reoperation. Freedom from autograft reoperation at 13 years was 69 ± 7%. Freedom from allograft reoperation for structural failure at 13 years was 87 ± 5%. Risk factors for autograft reoperation were previous AVR and adult patient age. Conclusion: Although survival of the Rotterdam autograft cohort is excellent, over time a worrisome increase in reoperation rate is observed. Given the progressive autograft dilatation, careful follow-up of these patients is warranted in the second decade after operation. </description>
    </item> <item>
      <title>Allografts for aortic valve or root replacement: insights from an 18-year single-center prospective follow-up study (Article)</title>
      <link>http://repub.eur.nl/res/pub/36657/</link>
      <pubDate>2007-05-01T00:00:00Z</pubDate>
      <description>Objective: Whether allografts are the biological valve of choice for AVR in non-elderly patients remains a topic of debate. In this light we analyzed our ongoing prospective allograft AVR cohort and compared allograft durability with other biological aortic valve substitutes. Methods: Between April 1987 and October 2005, 336 patients underwent 346 allograft AVRs (95 subcoronary, 251 root replacement). Patient and perioperative characteristics, cumulative survival, freedom from reoperation, and valve-related events were analyzed. Using microsimulation, for adult patients, age-matched actual freedom from allograft reoperation was compared to porcine and pericardial bioprostheses. Results: Mean age was 45 years (range 1 month to 83 years); 72% were males. Etiology was mainly endocarditis 32% (active 22%), congenital 31%, degenerative 9%, and aneurysm/dissection 12%. Twenty-seven percent underwent prior cardiac surgery. Hospital mortality was 5.5% (N = 19). During follow-up (mean 7.4 years, maximum 18.5 years, 98% complete), 54 patients died; there were 57 valve-related reoperations (3 early technical, 11 non-structural, 39 structural valve deterioration (SVD), 4 endocarditis), 5 cerebrovascular accidents, 1 fatal bleeding, 8 endocarditis. Twelve-year cumulative survival was 71% (SE 3), freedom from reoperation for SVD 77% (SE 4); younger patient age was associated with increased SVD rates. Actual risk of allograft reoperation was comparable to porcine and pericardial bioprostheses in a simulated age-matched population. Conclusions: The use of allografts for AVR is associated with low occurrence rates of most valve-related events, but over time the risk of SVD increases, comparable to stented xenografts. It remains in our institute the preferred valve substitute only for patients with active aortic root endocarditis and for patients in whom anticoagulation should be avoided. </description>
    </item> <item>
      <title>Dissection of a dilated autograft root (Article)</title>
      <link>http://repub.eur.nl/res/pub/35564/</link>
      <pubDate>2007-03-01T00:00:00Z</pubDate>
      <description></description>
    </item>
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