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Featured researches published by Tjark Ebels.


Journal of The American Society of Nephrology | 2004

Immediate Postoperative Renal Function Deterioration in Cardiac Surgical Patients Predicts In-Hospital Mortality and Long-Term Survival

Berthus G. Loef; Anne H. Epema; Ton D. Smilde; Robert H. Henning; Tjark Ebels; Gerjan Navis; Coen A. Stegeman

Postoperative renal function deterioration is a serious complication after cardiac surgery with cardiopulmonary bypass and is associated with increased in-hospital mortality. However, the long-term prognosis of patients with postoperative renal deterioration is not fully determined yet. Therefore, both in-hospital mortality and long-term survival were studied in patients with postoperative renal function deterioration. Included were 843 patients who underwent cardiac surgery with cardiopulmonary bypass in 1991. Postoperative renal function deterioration (increase in serum creatinine in the first postoperative week of at least 25%) occurred in 145 (17.2%) patients. In these patients, in-hospital mortality was 14.5%, versus 1.1% in patients without renal function deterioration (P < 0.001). Multivariate analysis significantly associated in-hospital mortality with postoperative renal function deterioration, re-exploration, postoperative cerebral stroke, duration of operation, age, and diabetes. In patients who were discharged alive, during long-term follow-up (100 mo), mortality was significantly increased in the patients with renal function deterioration (n = 124) as compared with those without renal function deterioration (hazard ratio 1.83; 95% confidence interval 1.38 to 3.20). Also after adjustment for other independently associated factors, the risk for mortality in patients with postoperative renal function deterioration remained elevated (hazard ratio 1.63; 95% confidence interval 1.15 to 2.32). The elevated risk for long-term mortality was independent of whether renal function had recovered at discharge from hospital. It is concluded that postoperative renal function deterioration in cardiac surgical patients not only results in increased in-hospital mortality but also adversely affects long-term survival.


The Annals of Thoracic Surgery | 1999

Procoagulant activity after off-pump coronary operation: is the current anticoagulation adequate?

Massimo A. Mariani; Y. John Gu; Piet W. Boonstra; Jan G. Grandjean; Willem van Oeveren; Tjark Ebels

BACKGROUND Hemostasis is preserved after off-pump coronary operations compared with conventional coronary procedures. However, this preserved hemostasis may result in a procoagulant activity. METHODS We prospectively studied coagulation in 22 patients who underwent off-pump coronary operation either through a midline sternotomy (n = 14) or with minimally invasive anterolateral thoracotomy (n = 8). RESULTS Procoagulant activity, represented by prothrombin factor 1 and 2, remained at baseline levels during operation but increased significantly on postoperative day 1. Factor VII remained at baseline levels during the operation but decreased significantly on postoperative day 1. Fibrinolysis was increased as indicated by the fibrin degradation products on postoperative day 1. A promoted hemostasis attributable to endothelial activation was indicated by the increase in von Willebrand factor on postoperative day 1. Platelets counts and platelet activation (beta-thromboglobulin) remained at baseline levels after the operation. No adverse clinical events occurred. CONCLUSIONS Patients undergoing off-pump coronary operation show an increased procoagulant activity in the first postoperative 24 hours regardless of the surgical approach (midline sternotomy or anterolateral thoracotomy). This procoagulant activity is not mediated by platelet-related factors. Therefore, a specific perioperative prophylactic pharmacologic regimen is advisable.


The Annals of Thoracic Surgery | 1995

RETRANSFUSION OF SUCTIONED BLOOD DURING CARDIOPULMONARY BYPASS IMPAIRS HEMOSTASIS

Jacob de Haan; Piet W. Boonstra; Stefan H.J. Monnink; Tjark Ebels; Willem van Oeveren

In a previous study we observed extensive clotting and fibrinolysis in blood from the thoracic cavities during cardiopulmonary bypass. We hypothesized that retransfusion of this suctioned blood could impair hemostasis. In this prospective clinical study we investigated the effect of suctioned blood retransfusion on systemic blood activation and on postoperative hemostasis. During coronary artery bypass grafting in 40 patients, suctioned blood was collected separately. It then was retransfused to the patient at the end of the operation (n = 19), or it was retained (n = 21). During the study, 12 consecutive patients, randomized in two groups of 6, were analyzed for biochemical parameters indicating blood activation and clotting. The immediate and significant increase in circulating concentrations of thrombin-antithrombin III complex, tissue-type plasminogen activator, fibrin degradation products, and free plasma hemoglobin demonstrated the effect of suctioned blood retransfusion. Moreover, the increased concentrations of thrombin-antithrombin III complex and fibrin degradation products indicated renewed systemic clotting and fibrinolysis as a direct result of the retransfusion of suctioned blood. Concentrations of all indicators mentioned remained significantly lower in the retainment group. The clinical data showed that retainment of suctioned blood resulted in significantly decreased postoperative blood loss (822 mL in the retransfusion group versus 611 mL in the retainment group; p < 0.05) and similar or even reduced consumption of blood products (513 versus 414 mL red blood cell concentrate and 384 versus 150 mL single-donor plasma; both not significant). We conclude that retransfusion of highly activated suctioned blood during cardiopulmonary bypass exacerbates wound bleeding.


The Journal of Thoracic and Cardiovascular Surgery | 1994

Influence of age on survival, late hypertension, and recoarctation in elective aortic coarctation repair. Including long-term results after elective aortic coarctation repair with a follow-up from 25 to 44 years.

René M.H.J. Brouwer; Michiel E. Erasmus; Tjark Ebels; A. Eijgelaar

The optimal age for elective repair of aortic coarctation is controversial. The optimal age should be associated with a minimal risk of recoarctation, late hypertension, and other cardiovascular disorders. The purpose of this retrospective study is to determine the actuarial survival after aortic coarctation repair 25 years or more after operation and to calculate the optimal age for elective aortic coarctation repair. From 1948 to 1966, 120 consecutive patients underwent aortic coarctation repair. Eighty-seven were male (72.5%). The mean age at operation was 15.5 years (SD +/- 9.1 years). Resection and end-to-end anastomosis was performed in 103 patients (85.8%). Early mortality occurred in 6 patients as a result of surgical problems, whereas late mortality in 15 patients was predominantly caused by cardiac causes. The mean follow-up period was 32 years (range 25 to 44.2 years). Ninety-two patients 96.8%) were in New York Heart Association class I. The probability of survival 44 years after operation was 73%. Patients younger than 10 years at operation had the highest probability of survival at 97%. Multivariate analysis produced age at operation as the only incremental risk factor for the occurrence of recoarctation, of late hypertension, and of premature death. So that these sequelae can be avoided, elective aortic coarctation repair should be performed around 1.5 years of age. At that age, the probability of recoarctation will have decreased to less than 3%, and the probability of upper body normotension and long-term survival will be optimal.


Heart | 2006

Pregnancy and delivery in women after Fontan palliation.

W Drenthen; Petronella G. Pieper; J.W. Roos-Hesselink; W A van Lottum; A.A. Voors; B.J.M. Mulder; A.P.J. van Dijk; Hubert W. Vliegen; Krystyna M. Sollie; Philip Moons; Tjark Ebels; D. J. Van Veldhuisen

Objectives: To evaluate the outcome of pregnancy in women after Fontan palliation and to assess the occurrence of infertility and menstrual cycle disorders. Design and patients: Two congenital heart disease registries were used to investigate 38 female patients who had undergone Fontan palliation (aged 18–45 years): atriopulmonary anastomosis (n  =  23), atrioventricular connection (n  =  5) and total cavopulmonary connection (n  =  10). Results: Six women had 10 pregnancies, including five miscarriages (50%) and one aborted ectopic pregnancy. During the remaining four live-birth pregnancies clinically significant complications were encountered: New York Heart Association class deterioration; atrial fibrillation; gestational hypertension; premature rupture of membranes; premature delivery; fetal growth retardation and neonatal death. Four of seven women who had attempted to become pregnant reported female infertility: non-specified secondary infertility (n  =  2), uterus bicornis (n  =  1) and related to endometriosis (n  =  1). Moreover, several important menstrual cycle disorders were documented. In particular, the incidence of primary amenorrhoea was high (n  =  15, 40%), which resulted in a significant increase in age at menarche (14.6 (SD 2.1) years, p < 0.0001, compared with the general population). Conclusion: Women can successfully complete pregnancy after adequate Fontan palliation without important long-term sequelae, although it is often complicated by clinically significant (non-)cardiac events. In addition, subfertility or infertility and menstrual disorders were common.


Circulation | 1998

Low Recurrence of Angina Pectoris After Coronary Artery Bypass Graft Surgery With Bilateral Internal Thoracic and Right Gastroepiploic Arteries

Tm Bergsma; Jg Grandjean; Adriaan A. Voors; Pw Boonstra; P den Heyer; Tjark Ebels

BACKGROUND In the past 10 years, there has been a trend to use more arterial grafts instead of vein grafts for coronary artery bypass graft surgery. Although there are many reports on the short- and mid-term follow-up of patients who underwent arterial revascularization with 1 or 2 arteries, little has been reported on the follow-up of patients with 3-vessel disease who received 3 arteries. METHODS AND RESULTS We reviewed a group of 256 patients with 3-vessel disease who received the right gastroepiploic artery together with both internal thoracic arteries (ITAs). Vein grafts were not used in these patients. The patients were monitored for up to 7 years (mean, 51+/-15 months). Seven-year actuarial survival was 91.1%. The cumulative probability of event-free survival for myocardial infarction, reintervention, and angina pectoris at 7 years was 97.3%, 95.4%, and 85.4%, respectively. CONCLUSIONS We conclude that concomitant use of the gastroepiploic artery with both ITAs results in low mortality and a low incidence of myocardial infarction and reintervention at follow-up. Most interestingly, we found 85.4% freedom from angina pectoris after 7 years, which is considerably lower than the results of studies in which vein grafts, single ITA grafts, or double ITA grafts are used. These results strongly support the use of both ITAs and the right gastroepiploic artery for bypass grafting in patients with 3-vessel disease.


European Heart Journal | 2010

The relation between volume and outcome of coronary interventions: a systematic review and meta-analysis

Piet N. Post; Michiel Kuijpers; Tjark Ebels; Felix Zijlstra

AIMS Although various studies reported better outcomes in centres performing a high volume of procedures of coronary artery bypass grafting (CABG) or percutaneous coronary interventions (PCIs), it is unclear how strong this relation is and whether it pertains to todays practice. METHODS AND RESULTS Medline, Embase, and conference reports were searched for studies reporting the effect of high volume of CABG or PCI on in-hospital mortality, adjusted for differences in case-mix. Of 140 potentially relevant papers, 15 were included, 2 of which reported data on both CABG and PCI. Meta-analysis of 10 studies on PCI, comprising 1 322 342 patients in 1746 hospitals, indicated an odds ratio (OR) of in-hospital mortality for patients treated in a high-volume hospital of 0.87 (95% confidence interval (CI) 0.83-0.91) compared to those treated in a low-volume hospital. The 7 CABG studies taken together, comprising 1 470 990 patients in 2040 hospitals, also revealed a significant effect of high volume (OR 0.85; CI 0.79-0.92). A differential effect for specific cut-off points could not be identified. Meta-regression did not show notable changes in the effect size over the years. CONCLUSIONS Patients undergoing CABG or PCI in a high-volume hospital exhibit lower in-hospital mortality than those treated at low-volume hospitals. Our meta-analysis does not support the view that this relation has attenuated over time.


European Journal of Cardio-Thoracic Surgery | 2000

Phosphorylcholine coating of extracorporeal circuits provides natural protection against blood activation by the material surface

F De Somer; Katrien François; van Willem Oeveren; Jan Poelaert; Daniël De Wolf; Tjark Ebels; G. Van Nooten

OBJECTIVE The aim of this study is to evaluate the use of a new coating, mimicking the outer cell membrane, in paediatric cardiac surgery. METHODS Two groups of ten patients with a body weight below 8 kg, undergoing elective cardiac operations for different congenital anomalies, were prospectively enrolled in this study. In one group the whole extracorporeal circuit, including the cannulas, was coated with phosphorylcholine (PC). In the second group the same circuit was used without coating. Platelet activation (thromboxane B2 (TXB2), beta-thromboglobulin (betaTG)), activation of the coagulation system (F1+2), leukocyte activation (CD11b/CD18) and terminal complement activation (TCC) were analyzed pre-cardiopulmonary bypass (CPB), at 15, 60 min of CPB, at the end of CPB, 20 min post CPB and at postoperative day 1 and 6. RESULTS No statistical differences were found for F1+2 and CD11b/CD18. After onset of CPB mean levels of TCC remained stable in the PC group whereas an increase was observed in the control group. During CPB betaTG values in both groups increased to a maximum at the end of CPB. Within groups the increase in betaTG levels during CPB was statistically significant (P<0.05) from baseline in the control group starting from 60 min of CPB whereas no statistical difference was observed in the PC group. After the start of CPB TXB2 mean levels increased to 405+/-249 pg/ml in the PC group vs. 535+/-224 pg/ml in the control group. After this initial increase there was a small decline in the PC group with further increase. This was in contrast to the control group were TXB2 levels further increased up to a mean of 718+/-333 pg/ml at the end of CPB (P=0.016). CONCLUSIONS Phosphorylcholine coating had a favourable effect on blood platelets, which is most obvious after studying the changes during cardiopulmonary bypass. A steady increase of TXB2 and betaTG was observed in the control group, whereas plateau formation was observed in the phosphorylcholine group. Clinically, this effect may contribute to reduced blood loss and less thromboembolic complications. Complement activation is lower in the coated group.


Heart | 2005

Pregnancy, fertility, and recurrence risk in corrected tetralogy of Fallot.

Jiska Meijer; Petronella G. Pieper; W Drenthen; A.A. Voors; J.W. Roos-Hesselink; A.P.J. van Dijk; B.J.M. Mulder; Tjark Ebels; D. J. Van Veldhuisen

Objective: To determine in women with surgically corrected tetralogy of Fallot the risk of pregnancy for mother and fetus, whether fertility was compromised, and the recurrence risk of congenital heart disease. Design: Data were collected from 83 patients through interviews and review of medical records. Results: In 29 patients 63 pregnancies were observed, of which 13 ended in an abortion. Fifty successful pregnancies were observed in 26 patients. During six successful pregnancies (12%) complications (symptomatic right sided heart failure, arrhythmias, or both) occurred. Both patients who developed symptomatic heart failure had severe pulmonary regurgitation. No clear relation between offspring mortality, premature birth or being small for gestational age, and cardiac characteristics of the mother was identified. Fifty seven patients were childless (41 (72%) voluntarily). Recurrence risk for congenital heart disease was 2.2%. Infertility was uncommon. Conclusions: Although complications did occur in five of 26 (19%) of the patients with a corrected tetralogy of Fallot, pregnancy was generally well tolerated in this largest report so far. No obvious predictors for maternal events or child outcome were determined, except for a possible relation between severe pulmonary regurgitation and symptomatic heart failure.


European Journal of Cardio-Thoracic Surgery | 2010

Chronic ischaemic mitral regurgitation. Current treatment results and new mechanism-based surgical approaches

Wobbe Bouma; Iwan C. C. van der Horst; Inez J. Wijdh-den Hamer; Michiel E. Erasmus; Felix Zijlstra; Massimo A. Mariani; Tjark Ebels

Chronic ischaemic mitral regurgitation (CIMR) remains one of the most complex and unresolved aspects in the management of ischaemic heart disease. This review provides an overview of the present knowledge about the different aspects of CIMR with an emphasis on mechanisms, current surgical treatment results and new mechanism-based surgical approaches. CIMR occurs in approximately 20-25% of patients followed up after myocardial infarction (MI) and in 50% of those with post-infarct congestive heart failure (CHF). The presence of CIMR adversely affects prognosis, increasing mortality and the risk of CHF in a graded fashion according to CIMR severity. The primary mechanism of CIMR is ischaemia-induced left ventricular (LV) remodelling with papillary muscle displacement and apical tenting of the mitral valve leaflets. CIMR is often clinically silent, and colour-Doppler echocardiography remains the most reliable diagnostic tool. The most commonly performed surgical procedure for CIMR (restrictive annuloplasty combined with coronary artery bypass grafting (CABG)) can provide good results in selected patients with minimal LV dilatation and minimal tenting. However, in general the persistence and recurrence rate (at least MR grade 3+) for restrictive annuloplasty remains high (up to 30% at 6 months postoperatively), and after a 10-year follow-up there does not appear to be a survival benefit of a combined procedure compared to CABG alone (10-year survival rate for both is approximately 50%). Patients at risk of annuloplasty failure based on preoperative echocardiographic and clinical parameters may benefit from mitral valve replacement with preservation of the subvalvular apparatus or from new alternative procedures targeting the subvalvular apparatus including the LV. These new procedures include second-order chordal cutting, papillary muscle repositioning by a variety of techniques and ventricular approaches using external ventricular restraint devices or the Coapsys device. In addition, percutaneous transvenous repair techniques are being developed. Although promising, at this point these new procedures still lack investigation in large patient cohorts with long-term follow-up. They will, however, be the subject of much anticipated and necessary ongoing and future research.

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Joost P. van Melle

University Medical Center Groningen

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Petronella G. Pieper

University Medical Center Groningen

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Rolf M.F. Berger

University Medical Center Groningen

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Bohdan Maruszewski

Memorial Hospital of South Bend

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A. Eijgelaar

University of Groningen

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Adriaan A. Voors

University Medical Center Groningen

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Tineke P. Willems

University Medical Center Groningen

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Duccio Di Carlo

Boston Children's Hospital

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