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Willem van Oeveren

Publications and source records attributed to Willem van Oeveren.

8 recordsLinked to original sources
PubMed2006

Clinical efficacy and biocompatibility of three different leukocyte and fat removal filters during cardiac surgery.

Activated leukocytes and fat particles are associated with organ injury after a cardiac surgery. Filters are currently used to remove either leukocytes or fat particles. A novel approach with a filter that combines leukocyte and fat removal might be clinically useful. As it is not known which type of filter has a good and safe performance in both leukocyte and fat removal, we measured in this study the leukocyte and fat removal properties and the biocompatibility of three different filters. We used six Pall RS1 (Pall, Portsmouth, England) leukocyte removal filters, six Pall LipiGuard fat removal filters, and six Fresenius Biofil 02 (Fresenius, Emmer-Compascuum, The Netherlands) leukocyte removal filters and measured the passage times of 500 and 1000 mL of residual heart-lung machine blood. We determined the circulating leukocyte and platelet counts, and total hemoglobin, triglyceride, and free fatty acid concentration after the filters. In addition, we measured free hemoglobin, plasma elastase (Merck, Darmstadt, Germany), and complement C5-9 (Quidel, San Diego, CA, U.S.A.) to assess the biocompatibility of the filters. The circulating fat particles were calculated with an automated hematology analyzer. The passage time for the blood was shortest for the Biofil filter (P = 0.02, analysis of variance). The total leukocyte counts (P = 0.04) and fat particles (P = 0.02) were higher after the LipiGuard filter. This filter also had a higher increase in free hemoglobin concentration (P = 0.03). We conclude that the leukocyte removal filters were superior to the fat removal filter both in leukocyte and fat removal.

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PubMed2006

Adhesion of thrombotic components to the surface of a clinically used oxygenator is not affected by Trillium coating.

The Trillium coating is designed to minimize adsorption of protein and the attachment of cells and other particles. The present study was undertaken to investigate the effect of surface coating on the adhesion of thrombotic components (activated platelets, white blood cells and fibrin) to the surface of a clinically used oxygenator. Twenty patients undergoing elective coronary artery bypass grafting (CABG) were randomized to one of the two oxygenator groups: non-coated (NC, n = 10) or Trillium-coated (TC, n = 10). Platelet and white blood cell counts and factor XIIa concentrations were determined prior to the induction of anesthesia and at the end of cardiopulmonary bypass (CPB). Binding of activated platelets, white blood cells and fibrin to the artificial surfaces was quantified by means of antibody binding and histological validation was achieved by scanning electron microscopy. Patient demographic and CPB data were similar for the two groups. No significant differences between the groups were found for any of the tested thrombotic components. However, observations from our scanning electron microscopy suggested a release of formed particles from the Trillium-coated surface. Primary adhesion of activated platelets, white blood cells and fibrin to the artificial surface of the venous blood inlet from an oxygenator is not affected by the Trillium surface coating under conditions of full systemic heparinization.

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PubMed2004

Invited commentary.

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Cardiopulmonary Bypass↗
PubMed2004

Clinical evaluation of a new fat removal filter during cardiac surgery.

OBJECTIVES: Fat microemboli are generated during cardiac surgery that are associated with post-operative organ injury. Recently, a fat removal filter has been developed, based on a polyester leukocyte depletion filter. However, the efficacy of such a filter in a clinical setting is unknown. In this study we tested the efficacy of this filter. METHODS: Coronary artery bypass patients were randomly divided into two groups. Group I: filtration of cardiotomy suction blood during cardiopulmonary bypass with a fat removal filter (n=14). Group II: control patients without filtration (n=14). Filter efficacy was evaluated in group I using biochemical assays and thin layer chromatography of blood samples taken simultaneously before and after the filter. In addition, clinical and biochemical markers for organ injury were determined in both groups. RESULTS: The fat filter removed triglycerides (0.9+/-0.08 vs. 0.63+/-0.08 mmol l(-1), P=0.004, paired t-test), leukocytes (4.3+/-0.8 x 10(9) vs. 2.3+/-0.6 x 10(9)l(-1), P=0.03), and platelets (116+/-26 x 10(9) vs. 75+/-21 x 10(9)l(-1), P=0.003) from the blood samples taken before and after the filter. Chromatography showed a significant reduction in free fatty acids, phospholipids and triglycerides. Clinically, leukocyte counts were similar, but platelet counts were higher (181+/-14 x 10(9) vs. 117+/-8.6 x 10(9)l(-1) control, P<0.001) in group I on the first postoperative day. CONCLUSIONS: The fat filter removed 40% fat, leukocytes and platelets from cardiotomy suction blood during cardiac surgery. A larger scale study is necessary to determine clinical effects on organ damage.

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PubMed2003

Generation of platelet-derived microparticles in patients undergoing cardiac surgery is not affected by complement activation.

OBJECTIVE: The mechanisms causing the presence of platelet-derived microparticles in the circulation are unknown. In vitro platelets release platelet-derived microparticles in response to complement activation. This study evaluates the relationship between complement activation and levels of circulating platelet-derived microparticles in patients undergoing cardiac surgery. METHODS: Prospectively, 71 patients were included who underwent elective coronary artery bypass grafting with cardiopulmonary bypass. The patients were randomly allocated to one of the 3 groups: uncoated oxygenator, UnModified Surface (n = 25) or oxygenator coated with either BioPassive Surface (n = 25) or BioActive Surface (n = 21). Platelet-derived microparticles and terminal complement complexes were determined before bypass and after induction of anesthesia, 15 minutes after the start of cardiopulmonary bypass, at the end of cardiopulmonary bypass, and 30 minutes after administration of protamine sulfate. RESULTS: Demographic and cardiopulmonary bypass data were similar for the 3 groups. At the end of cardiopulmonary bypass, platelet-derived microparticle numbers were decreased in all 3 groups. No significant differences were observed among the groups at any sampling point. At the end of cardiopulmonary bypass, terminal complement complex concentrations were increased in all groups (P <.001), and significant differences among the groups were present (P =.002). CONCLUSIONS: Despite significant complement activation, no increase in numbers of circulating platelet-derived microparticles was found in the systemic blood of patients undergoing cardiac surgery with cardiopulmonary bypass. Thus complement activation in vivo does not necessarily affect generation of platelet-derived microparticles.

Adult↗
PubMed2003

Leucocyte depletion during cardiac surgery: a comparison of different filtration strategies.

The results of leucocyte filtration during cardiac surgery are conflicting. This may be due to timing and duration of the filtration procedure, and to flow and pressure conditions in the filter. Therefore, we prospectively compared three major leucocyte filtration strategies in cardiac surgical patients. Forty patients were randomly divided into four groups. Group I: leucofiltration of arterial blood throughout cardiopulmonary bypass (CPB) (associated with high-flow and pressure gradients), Group II: leucofiltration of a part of the venous return blood in the rewarming phase during CPB (associated with intermediate flow, but high pressure), Group III: leucofiltration of residual heart-lung machine blood during transfusion into the patient after CPB (associated with low flow and low pressure), Group IV: control group without leucofiltration. We measured circulating leucocyte counts, plasma elastase levels and arterial blood oxygenation. Filters were postoperatively examined using scanning electronmicroscopy (SEM). Leucocyte counts increased over time and oxygenation decreased in all groups, without significant differences between the groups. SEM demonstrated extensive protein deposits and damaged leucocytes in the deeper layers of the filters from Group I. This was not observed in the filters from Group III. The postoperative plasma elastase levels increased in Groups II and IV and decreased in Groups I and III. In conclusion, we could not demonstrate a clinical difference among the three leucocyte depletion strategies. However, our laboratory results suggest that leucocyte filtration at low flow and pressure conditions is associated with less leucocyte damage and less release of elastase.

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PubMed2002

Increased neutrophil priming and sensitization before commencing cardiopulmonary bypass in cardiac surgical patients.

BACKGROUND: Neutrophil activation is implicated in postoperative complications in patients having cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to determine the temporal fluctuations in the primability of neutrophils in the preoperative, intraoperative, and postoperative periods of CPB, and specifically whether CPB was a primary cause leading to increased neutrophil priming and elastase release. METHODS: Twenty patients undergoing multiple coronary bypass grafting, valve replacement, or both of these procedures were included in this study. Blood samples were taken 1 day before the operation and at several time points during and after the operation. For each sample, blood was divided in vitro into four subgroups: control without priming, priming alone with cytochalasin B (CytoB), priming plus stimulation with platelet-activating factor (PAF), and priming plus stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP). The elastase concentration of all these samples was determined using the enzyme immunoassay. RESULTS: Compared with the controls, CytoB priming increased release of elastase more than 10-fold before CPB, 1.6-fold during CPB, and 1.5-fold at the end of CPB. Further stimulation with PAF or fMLP showed greater increase of elastase than priming alone, with peak values in both found before CPB. This increased neutrophil primability prior to CPB did not differ significantly among patients who had different preoperative disease profiles. CONCLUSIONS: Our data suggest that neutrophil priming occurs early before commencing CPB in cardiac surgical patients, and that CPB is not the primary primer. Anesthesia, surgical trauma, and other events may have been involved in neutrophil priming and sensitization before CPB, which warrants further investigation.

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