Detecting Oxygenator Thrombosis in ECMO: A Review of Current Techniques and an Exploration of Future Directions.

Extracorporeal membrane oxygenation (ECMO) is a life-support technique used to treat cardiac and pulmonary failure, including severe cases of COVID-19 (coronavirus disease 2019) involving acute respiratory distress syndrome. Blood clot formation in the circuit is one of the most common complications in ECMO, having potentially harmful and even fatal consequences. It is therefore essential to regularly monitor for clots within the circuit and take appropriate measures to prevent or treat them. A review of the various methods used by hospital units for detecting blood clots is presented. The benefits and limitations of each method are discussed, specifically concerning detecting blood clots in the oxygenator, as it is concluded that this is the most critical and challenging ECMO component to assess. We investigate the feasibility of solutions proposed in the surrounding literature and explore two areas that hold promise for future research: the analysis of small-scale pressure fluctuations in the circuit, and real-time imaging of the oxygenator. It is concluded that the current methods of detecting blood clots cannot reliably predict clot volume, and their inability to predict clot location puts patients at risk of thromboembolism. It is posited that a more in-depth analysis of pressure readings using machine learning could better provide this information, and that purpose-built imaging could allow for accurate, real-time clotting analysis in ECMO components.

Optimization of the IntraVascular Oxygenator Catheter Using Angular Oscillation.

We demonstrate a methodology which both improves oxygen transport and reduces or eliminates bubble formation in a novel hyperbaric membrane oxygenator catheter model system. Angular oscillations were introduced to a bundle of hollow fiber membranes (HFMs) supplied with hyperbaric 100% oxygen at average gauge pressures up to 0.35 barg. Oscillating bundles enabled delivery of an oxygen flux of up to 400 mL min-1 m-2 in an aqueous solution, a doubling over a previous non-oscillating setup. Similarly, the addition of angular oscillations facilitated a five-fold reduction in pressure to achieve similar oxygen flux. The increased angular speed of oscillation improved flux, while the addition of angular micro-oscillation variations resulted in flux reductions of 7-20% compared to continuous macro-oscillation only, depending on mixing conditions. However, semi-quantitative visual observation demonstrated that angular oscillations reduced or eliminated the instance of oxygen bubble formation on the HFMs. The modeled mass transfer coefficients indicated a quasi linear relationship between rotational velocity and flux, suggesting that faster oscillation speeds could further improve oxygen mass transport allowing for HFM bundles to maintain high oxygen fluxes while eliminating bubble formation. This encourages further development of our compact oxygenating catheter that could be used intravascularly.

Computational fluid dynamics-based design and in vitro characterization of a novel pediatric pump-lung.

BACKGROUND: Although extracorporeal membrane oxygenation (ECMO) has been used to provide temporary support for pediatric patients suffering severe respiratory or cardiac failure since 1970, ECMO systems specifically designed for pediatric patients, particularly for long-term use, remain an unmet clinical need. We sought to develop a new pediatric ECMO system, that is, pediatric pump-lung (PPL), consisting of a unique cylinder oxygenator with an outside-in radial flow path and a centrifugal pump. METHODS: Computational fluid dynamics was used to analyze the blood fluid field for optimized biocompatible and gas exchange performances in terms of flow characteristics, hemolysis, and gas transfer efficiency. Ovine blood was used for in vitro hemolysis and gas transfer testing. RESULTS: Both the computational and experimental data showed that the pressure drop through the PPL's oxygenator is significantly low, even at a flow rate of more than 3.5 L/min. The PPL showed better hemolysis performance than a commercial ECMO circuit consisting of the Quadrox-iD pediatric oxygenator and the Rotaflow pump at a 3.5 L/min flow rate and 250 mm Hg afterload pressure. The oxygen transfer rate of the PPL can reach over 200 mL/min at a flow rate of 3.5 L/min. CONCLUSIONS: The PPL has the potential to provide adequate blood pumping and excellent respiratory support with minimal risk of hemolysis for a wide range of pediatric patients.

Using Cardiohelp, Quadrox, and Nautilus Extracorporeal Membrane Oxygenators as Vascular Access for Hemodialysis, Continuous Renal Replacement Therapy, and Plasmapheresis: A Brief Technical Report.

The use of intermittent hemodialysis (iHD), and continuous renal replacement therapy (CRRT), along with extracorporeal membrane oxygenation (ECMO) in patients with acute kidney injury (AKI) and end-stage renal disease (ESRD) is very common. In this technical report, we describe the methods to perform these dialytic therapies safely and effectively using the ECMO circuit in lieu of a separate dialysis catheter. Specifically, we describe in detail how to connect these kidney replacement therapy modalities to a Quadrox, Nautilus, and Cardiohelp HLS (combined oxygenator and pump) oxygenator. The dialysis (iHD or CRRT) inlet is attached to the post-oxygenators Luer-Lock, whereas the return is attached to the pre-oxygenator Luer-Lock, both with a dual lumen pigtail. We also discuss the technical aspects of performing plasmapheresis in conjunction with ECMO and iHD or CRRT. Finally, we highlight the fact that the reported technique does not require modifying the ECMO cannulas/tubing which helps maximize safety.

Refurbishment of Extracorporeal Life Support Oxygenators in the Context of In Vitro Testing.

Refurbishing single use extracorporeal membrane oxygenation (ECMO) oxygenators for in vitro research applications is common. However, the refurbishment protocols that are established in respective laboratories have never been evaluated. In the present study, we aim at proving the relevance of a well-designed refurbishing protocol by quantifying the burden of repeatedly reused oxygenators. We used the same three oxygenators in 5 days of 6 hours whole blood experiments. During each experiment day, the performance of the oxygenators was measured through the evaluation of gas transfer. Between experiment days, each oxygenator was refurbished applying three alternative refurbishment protocols based on purified water, pepsin and citric acid, and hydrogen peroxide solutions, respectively. After the last experiment day, we disassembled the oxygenators for visual inspection of the fiber mats. The refurbishment protocol based on purified water showed strong degeneration with a 40-50 %-performance drop and clearly visible debris on the fiber mats. Hydrogen peroxide performed better; nevertheless, it suffered a 20% decrease in gas transfer as well as clearly visible debris. Pepsin/citric acid performed best in the field, but also suffered from 10% performance loss and very few, but visible debris. The study showed the relevance of a well-suited and well-designed refurbishment protocol. The distinct debris on the fiber mats also suggests that reusing oxygenators is ill-advised for many experiment series, especially regarding hemocompatibility and in vivo testing. Most of all, this study revealed the relevance of stating the status of test oxygenators and, if refurbished, comment on the implemented refurbishment protocol in detail.

Prevalence and Indications for Oxygenator Circuit Replacement in Patients Receiving Venovenous Extracorporeal Membrane Oxygenation.

In this retrospective observational cohort study, we aimed to describe the rate of extracorporeal membrane oxygenation (ECMO) circuit change, the associated risk factors and its relationship with patient characteristics and outcome in patients receiving venovenous (VV) ECMO at our center between January 2015 and November 2017. Twenty-seven percent of the patients receiving VV ECMO (n = 224) had at least one circuit change, which was associated with lower ICU survival (68% vs 82% p=0.032) and longer ICU stay (30 vs . 17 days p < 0.001). Circuit duration was similar when stratified by gender, clinical severity, or prior circuit change. Hematological abnormalities and increased transmembrane lung pressure (TMLP) were the most frequent indication for circuit change. The change in transmembrane lung resistance (Δ TMLR) gave better prediction of circuit change than TMLP, TMLR, or ΔTMLP. Low postoxygenator PO 2 was indicated as a reason for one-third of the circuit changes. However, the ECMO oxygen transfer was significantly higher in cases of circuit change with documented "low postoxygenator PO 2 " than those without (244 ± 62 vs. 200 ± 57 ml/min; p = 0.009). The results suggest that circuit change in VV ECMO is associated with worse outcomes, that the Δ TMLR is a better predictor of circuit change than TMLP, and that the postoxygenator PO 2 is an unreliable proxy for the oxygenator function.

Oxygenation performance assessment of an artificial lung in different central anatomic configurations.

OBJECTIVES: Aim of this work was to characterize possible central anatomical configurations in which a future artificial lung (AL) could be connected, in terms of oxygenation performance. METHODS: Pulmonary and systemic circulations were simulated using a numerical and an in vitro approach. The in vitro simulation was carried out in a mock loop in three phases: (1) normal lung, (2) pulmonary shunt (50% and 100%), and (3) oxygenator support in three anatomical configurations: right atrium-pulmonary artery (RA-PA), pulmonary artery-left atrium (PA-LA), and aorta-left atrium (Ao-LA). The numerical simulation was performed for the oxygenator support phase. The oxygen saturation (SO2) of the arterial blood was plotted over time for two percentages of pulmonary shunt and three blood flow rates through the oxygenator. RESULTS: During the pulmonary shunt phase, SO2 reached a steady state value (of 68% for a 50% shunt and of nearly 0% for a 100% shunt) 20 min after the shunt was set. During the oxygenator support phase, physiological values of SO2 were reached for RA-PA and PA-LA, in case of a 50% pulmonary shunt. For the same conditions, Ao-LA could reach a maximum SO2 of nearly 60%. Numerical results were congruous to the in vitro simulation ones. CONCLUSIONS: Both in vitro and numerical simulations were able to properly characterize oxygenation properties of a future AL depending on its placement. Different anatomical configurations perform differently in terms of oxygenation. Right to right and right to left connections perform better than left to left ones.

α-Fe2O3@Au-PEG-Ce6-Gd Nanoparticles as Acidic H2O2-Driven Oxygenators for Multimodal Imaging and Synergistic Tumor Therapy.

Nanoparticles with visual imaging capabilities and synergistic therapeutics have a bright future in antitumor applications. However, most of the current nanomaterials lack multiple imaging-guided therapeutic capabilities. In this study, a novel enhanced photothermal photodynamic antitumor nanoplatform with photothermal imaging, fluorescence (FL) imaging, and MRI-guided therapeutic capabilities was constructed by grafting gold, dihydroporphyrin Ce6, and Gd onto α-iron trioxide. This antitumor nanoplatform can convert NIR light into local hyperthermia at a temperature of up to 53 °C under NIR light irradiation, while Ce6 can generate singlet oxygen, which further synergizes the tumor-killing effect. At the same time, α-Fe2O3@Au-PEG-Ce6-Gd can also have significant photothermal imaging effect under light irradiation, which can guide to see the temperature change near the tumor tissue. It is worth noting that α-Fe2O3@Au-PEG-Ce6-Gd can have obvious MRI and FL imaging effects after tail vein injection in mice with blood circulation, realizing imaging-guided synergistic antitumor therapy. α-Fe2O3@Au-PEG-Ce6-Gd NPs provide a new solution for tumor imaging and treatment.

Additional Extracorporeal Membrane Oxygenation Pump Without an Oxygenator for Transseptal Left Atrial Decompression: A Case Report.

A 63-year-old man developed chest pain and dyspnea. Venoarterial-venous extracorporeal membrane oxygenation (ECMO) was applied to the patient due to failing heart after percutaneous coronary intervention. We used an additional ECMO pump without an oxygenator for transseptal left atrial (LA) decompression and performed a heart transplant. Transseptal LA decompression with venoarterial ECMO is not always effective for severe left ventricular dysfunction. Here, we report a case of the effective use of additional ECMO pump without an oxygenator for transseptal LA decompression through controlling the blood flow rate of the transseptal LA catheter.

Extended Cellular Deposits on Gas Exchange Capillaries Are Not an Indicator of Clot Formation: Analysis of Different Membrane Oxygenators.

Antithrombogenic coatings of artificial surfaces within extracorporeal membrane oxygenation (ECMO) circuits improved its bio- and hemocompatibility. However, there is still a risk of thrombus formation in particular within the membrane oxygenator (MO). Since inflammatory cells are essential components within clots, the aim was to identify the extent of cellular accumulations on gas exchange capillaries from different ECMO systems. Thirty-four MOs (PLS, n = 27, Getinge; Hilite 7000 LT, n = 7, Fresenius Medical Care, Germany) were collected from adult patients. The extent of cellular deposits on gas exchange capillaries was classified using nuclear 4',6-diamidino-2-phenylindole staining and fluorescence microscopy. All Hilite oxygenators exhibited small cellular deposits. In contrast, the cellular distribution was heterogeneous on capillaries from PLS oxygenators: small deposits (34%), clusters (44%) and membrane-spanning cell structures (pseudomembranes) (22%). Overall, the median fluorescence intensity was significantly higher in the PLS group. Nevertheless, within 3 days before MO removal, there was no alteration in critical parameters ( d -dimer and fibrinogen levels, platelet counts, and pressure drop across the MO). In conclusion, despite the histological differences on the gas capillaries from different types of oxygenators, there was no further evidence of increased inflammation and coagulation parameters that indicate clot formation within oxygenators.

Clinical evaluation of two adult oxygenator systems in terms of mortality and major adverse events.

PURPOSE: The primary aim of this study was to examine the effects of two oxygenator systems on major adverse events and mortality. METHODS: A total of 181 consecutive patients undergoing coronary artery bypass grafting in our clinic were retrospectively analyzed. The patients were divided into two groups according to the oxygenator used: Group M, in which a Medtronic Affinity (Medtronic Operational Headquarters, Minneapolis, MN, USA) oxygenator was used, and Group S, in which a Sorin Inspire (Sorin Group Italia, Mirandola, Italy) oxygenator was used. RESULTS: Group S consisted of 89 patients, whereas Group M included 92 patients. No statistically significant differences were found between the two groups in terms of age (p = .112), weight (p = .465), body surface area (p = .956), or gender (p = .484). There was no statistically significant difference in hemorrhage on the first or second postoperative day (p = .318 and p = .455, respectively). No statistically significant differences were observed in terms of red blood cell (p = .468), fresh frozen plasma (p = .116), or platelet concentrate transfusion (p = .212). Infections, wound complications, and delayed sternal closure were significantly more common in Group M (p = .006, p = .023, and p = .019, respectively). Extracorporeal membrane oxygenators and intra-aortic balloon pumps were required significantly more frequently in Group S (p = .025 and p = .013, respectively). Major adverse events occurred in 16 (18%) patients in Group S and 14 (15.2%) patients in Group M (p = .382). Mortality was observed in six (6.7%) patients in Group S and three (3.3%) patients in Group M (p = .232). No statistically significant difference was found between the two groups in terms of length of hospital stay (p = .451). CONCLUSION: The clinical outcomes of the two oxygenator systems, including mortality, major adverse events, hemorrhage, erythrocyte and platelet transfusions, and length of hospital stay, were similar.

Risk factors and treatment of oxygenator high-pressure excursions during cardiopulmonary bypass.

INTRODUCTION: A high-pressure excursion (HPE) is a sudden increase in oxygenator inlet pressure during cardiopulmonary bypass (CPB). The aims of this study were to identify factors associated with HPE, to describe a treatment protocol utilizing epoprostenol in severe cases, and to assess early outcome in HPE patients. METHODS: Patients who underwent cardiac surgery with cardiopulmonary bypass at Sahlgrenska University Hospital 2016-2018 were included in a retrospective observational study. Pre- and post-operative data collected from electronic health records, local databases, and registries were compared between HPE and non-HPE patients. Factors associated with HPE were identified with logistic regression models. RESULTS: In total, 2024 patients were analyzed, and 37 (1.8%) developed HPE. Large body surface area (adjusted Odds Ratio (aOR): 1.43 per 0.1 m2; 95% confidence interval (CI): 1.16-1.76, p < 0.001), higher hematocrit during CPB (aOR: 1.20 per 1%; (1.09-1.33), p < 0.001), acute surgery (aOR: 2.98; (1.26-6.62), p = 0.018), and previous stroke (aOR: 2.93; (1.03-7.20), p = 0.027) were independently associated with HPE. HPE was treated with hemodilution (n = 29, 78.4%), and/or extra heparin (n = 23, 62.2%), and/or epoprostenol (n = 12, 32.4%). No oxygenator change-out was necessary. While there was no significant difference in 30-day mortality (2.7% vs 3.2%, p = 1.0), HPE was associated with a higher perioperative stroke rate (8.1% vs 1.8%, aOR 5.09 (1.17-15.57), p = 0.011). CONCLUSIONS: Large body surface area, high hematocrit during CPB, previous stroke and acute surgery were independently associated with HPE. A treatment protocol including epoprostenol appears to be a safe option. Perioperative stroke rate was increased in HPE patients.

Hemodynamic oxygenator exchange-related effects during veno-venous extracorporeal membrane oxygenation for the treatment of acute SARS-CoV-2 respiratory distress syndrome.

Few patients with coronavirus disease 2019-associated severe acute respiratory distress syndrome (ARDS) require veno-venous extracorporeal membrane oxygenation (VV-ECMO). Prolonged VV-ECMO support necessitates repeated oxygenator replacement, increasing the risk for complications. Transient hypoxemia, induced by VV-ECMO stop needed for this procedure, may induce transient myocardial ischemia and acutely declining cardiac output in critically ill patients without residual pulmonary function. This is amplified by additional activation of the sympathetic nervous system (tachycardia, pulmonary vasoconstriction, and increased systemic vascular resistance). Immediate reinjection of the priming solution of the new circuit and induced acute iatrogenic anemia are other potentially reinforcing factors. The case of a critically ill patient presented here provides an instructive illustration of the hemodynamic relationships occurring during VV-ECMO support membrane oxygenator exchange.

Comparison of bubble removal performances of five membrane oxygenators with and without a pre-filter.

When employing minimal invasive extracorporeal circulation (MiECC), the removal of bubbles in the circuit is important to prevent air embolism. We investigated the bubble removal performance of the FHP oxygenator with a pre-filter and compared it with that of four oxygenators, including the Fusion oxygenator, Quadrox oxygenator, Inspire oxygenator, and FX oxygenator. A closed test circuit filled with an aqueous glycerin solution was used. Air injection (10 mL) was performed prior to the oxygenator, and the number and volume of the bubbles were measured at the inlet and outlet of each oxygenator. At the inlet of the five oxygenators, there were no significant differences in the total number of bubbles detected. At the outlet, bubbles were classified into two groups according to the bubble size: ≥100 µm and <100 µm. Tests were performed at pump flow rates of 4 and 5 L/min. For bubbles ≥100 µm, which are considered clinically detrimental, the FHP was the lowest number and volume of bubbles at both pump flow rates compared to the other oxygenators. Regarding the bubbles <100 µm, the number of bubbles was higher in the FHP than those in others; however, the volume of bubbles was significantly lower at 4 L/min and tended to be lower at 5 L/min. The use of the FHP with the pre-filter removed more bubbles ≥100 µm in the circuit than that by the other oxygenators.

The novel ProtekDuo ventricular assist device: Configurations, technical aspects, and present evidence.

The ProtekDuo, single site dual lumen cannula can be used in a multitude of configurations. In the medical literature, the ProtekDuo is described as right ventricular assist device (RVAD), as left ventricular assist device (LVAD), as biventricular assist device (BiVAD) when combined with an Impella device or other LVAD's, as double lumen drainage cannula on cardiopulmonary bypass (CPB), as RVAD with oxygenator, in veno-pulmonary (V-P) ECMO configuration, venovenous-pulmonary (VV-P) ECMO configuration with additional drainage cannula, and in veno-venopulmonary (V-VP) ECMO configuration as double lumen return cannula. Improvements in flow and oxygenation have been recognized in various settings and need further scientific evaluation. We summarized the above-mentioned configurations, technical aspects, and the present literature available for the ProtekDuo.

The Evolution of Extracorporeal Membrane Oxygenation Circuitry and Impact on Clinical Outcomes in Children: A Systematic Review.

This systematic review summarizes the major developments in extracorporeal membrane oxygenation (ECMO) circuitry in pediatrics over the past 20 years and demonstrates the impacts of those developments on clinical outcomes. This systematic review followed structured Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 1987 studies were retrieved, of which 82 were included in the final analysis. Over the past 20 years, ECMO pumps have shifted from roller pumps to centrifugal pumps. Silicone and polypropylene hollow fiber membrane oxygenators were initially used but have been replaced by polymethylpentene hollow fiber membrane oxygenators, with other ECMO components poorly reported. Considerable variability in mortality was found across studies and there was no statistical difference in mortality rates across different periods. The duration of ECMO and other outcome measures were inconsistently reported across studies. This systematic review demonstrated technological developments in pumps and oxygenators over the last two decades, although patient mortality rates remained unchanged. This could be because of ECMO support applied to patients in more critical conditions over the years. We also highlighted the limitations of methodology information disclosure and outcome measures in current ECMO studies, showing the need of reporting standardization for future ECMO studies.

Evaluation of the effects of three designs of oxygenators with integrated filters on clinical and haematological outcomes at an Australasian cardiothoracic unit.

INTRODUCTION: Cardiopulmonary bypass (CPB) machines have oxygenators with integrated filters and unique biocompatible coatings to combat systemic inflammatory response syndrome (SIRS) and mitigate coagulopathy. Contemporary oxygenators have undergone comparative studies; however, our study aimed to identify the most appropriate oxygenator for our regional Cardiothoracic unit in Australasia. METHODS: A prospective audit consecutively recruited one-hundred and fifty patients undergoing cardiac surgery at Waikato Hospital, New Zealand between the periods of 29th January 2018 and 31st July 2018. Fifty patients were recruited for each oxygenator arm: Sorin INSPIRE' (Group-S); Terumo CAPIOX'FX (Group-T); and Medtronic Affinity Fusion' (Group-M). The clinical outcomes were transfusions, chest drain output, reoperation and length of hospital stay (LOHS). Routine blood testing protocol included: haemoglobin, protein, albumin, white cell count (WCC), C-reactive protein (CRP), platelet count and coagulations tests including international normalized ratio (INR). RESULTS: Comparing Groups S, T and M there was no statistical difference in chest drain output (650 vs. 500 vs. 595 ml respectively, p = 0.45), transfusions (61 vs. 117 vs. 70 units, p = 0.67), reoperation (6 vs. 8 vs. 12%, p = 0.99) and LOHS (median 7.4 vs. 7.6 vs. 9.5 days, p = 0.42). Group-T had fewer SIRS cases but similar increase in CRP (p = 0.12) and WCC (p = 0.35). Group-M had a significant rise in post-op INR (p = 0.005) but no associated increase in chest drain output (p = 0.62). Group-S and -M required more 4%-albumin and Group-T had more transfusions. Only fresh frozen plasma (FFP) and red blood cell (RBC) transfusion had a significant relationship with LOHS (p < 0.05). CONCLUSION: Biochemically, there was slight difference among the oxygenators which did not translate into clinical difference in outcomes. The oxygenator design and perfusionist choice aided in our decision-making process.

Hematic Antegrade Repriming Reduces Emboli on Cardiopulmonary Bypass: A Randomized Controlled Trial.

Particulate and gaseous microemboli (GME) are side effects of cardiac surgery that interfere with postoperative recovery by causing endothelial dysfunction and vascular blockages. GME sources during surgery are multiple, and cardiopulmonary bypass (CPB) is contributory to this embolic load. Hematic antegrade repriming (HAR) is a novel procedure that combines the benefits of repriming techniques with additional measures, by following a standardized procedure to provide a reproducible hemodilution of 300 ml. To clarify the safety of HAR in terms of embolic load delivery, a prospective and controlled study was conducted, by applying Doppler probes to the extracorporeal circuit, to determine the number and volume of GME released during CPB. A sample of 115 patients (n = 115) was considered for assessment. Both groups were managed under strict normothermia, and similar clinical conditions and protocols, receiving the same open and minimized circuit. Significant differences in GME volume delivery (control group [CG] = 0.28 ml vs. HAR = 0.08 ml; p = 0.004) and high embolic volume exposure (>1 ml) were found between the groups (CG = 30.36% vs. HAR = 4.26%; p = 0.001). The application of HAR did not represent an additional embolic risk and provided a four-fold reduction in the embolic volume delivered to the patient (coefficient, 0.24; 95% CI, 0.08-0.72; p = 0.01), which appears to enhance GME clearance of the oxygenator before CPB initiation.

Development and evaluation of a variable, miniaturized oxygenator for various test methods.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) became an accepted therapy for the treatment of severe acute respiratory distress syndrome and chronic obstructive pulmonary disease. However, ECMO systems are still prone to thrombus formation and decrease of gas exchange over time. Therefore, it is necessary to conduct qualified studies to identify parameters for optimization of ECMO systems, and especially the oxygenator. However, commercially marketed oxygenators are not always appropriate and available for certain research use cases. Therefore, we aimed to design an oxygenator, which is suitable for various test conditions such as blood tests, numerical simulation, and membrane studies, and can be modified in membrane area size and manufactured in laboratory. METHODS: Main design criteria are a homogeneous blood flow without stagnation zones, low pressure drop, manufacturability in the lab, size variability with one set of housing parts and cost-efficiency. Our newly designed oxygenator was tested comparatively regarding blood cell damage, gas transfer performance and pressure drop to prove the validity of the design in accordance with a commercial device. RESULTS: No statistically significant difference between the tested oxygenators was detected and our new oxygenator demonstrated sufficient hemocompatibility. Furthermore, our variable oxygenator has proven that it can be easily manufactured in the laboratory, allows to use various membrane fiber configurations and can be reopened easily and non-destructively for analysis after use, and the original geometry is available for numerical simulations. CONCLUSION: Therefore, we consider this newly developed device as a valuable tool for basic experimental and numerical research on the optimization of oxygenators.