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Lantinga VA, Arykbaeva AS, Spraakman NA, Blom EWP, Huijink TM, de Vries DK, Ploeg RJ, Alwayn IPJ, Leuvenink HGD, Moers C, van Leeuwen LL. Impact of device variability and protocol differences on kidney function during normothermic machine perfusion: A comparative study using porcine and human kidneys. Artif Organs 2024. [PMID: 39193869 DOI: 10.1111/aor.14851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/21/2024] [Accepted: 08/12/2024] [Indexed: 08/29/2024]
Abstract
INTRODUCTION A growing interest in renal normothermic machine perfusion (NMP) has resulted in more clinically available perfusion devices. While all perfusion systems have the same aim, there are significant differences in their circuits, pumps, sensors, and software. Therefore, our objective was to assess the impact of different perfusion protocols and devices on kidney function and perfusion parameters during NMP. METHODS Porcine kidneys were subjected to 30 min of warm ischemia, 24 h of static cold storage, and subsequently perfused for 6 h using (1) the Kidney Assist (KA) machine with a pressure of 75 mm Hg, (2) the KA device incorporating several adjustments and a pressure of 85 mm Hg (modified KA), or (3) the Perlife (PL) perfusion device (n = 4). Consecutively, discarded human kidneys were perfused using the KA or modified KA (n = 3) protocol. RESULTS The PL group quickly reached the device's upper flow limit and consequently received a significantly lower pressure compared to the KA groups. The arterial pO2 was significantly lower in the PL group. Yet, hemoglobin concentration increased over time, and oxygen consumption was significantly higher compared to the KA groups. Fractional sodium excretion was significantly lower in the PL group. Tissue ATP levels, urine production, and creatinine clearance rates did not differ between groups. In human kidneys, the modified KA group showed significantly lower vascular resistance, higher oxygen delivery, and lower levels of lactate in the perfusate compared to the KA group. CONCLUSIONS This study shows that perfusion characteristics and kidney function are significantly influenced by the perfusion protocol and the device and its settings during normothermic machine perfusion and therefore should be interpreted with caution.
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Affiliation(s)
- Veerle A Lantinga
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Asel S Arykbaeva
- Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands
| | - Nora A Spraakman
- Department of Anaesthesiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Elwin W P Blom
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Tobias M Huijink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Dorottya K de Vries
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Rutger J Ploeg
- Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - Ian P J Alwayn
- Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands
| | - Henri G D Leuvenink
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Cyril Moers
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - L Leonie van Leeuwen
- Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
- Recanati/Miller Transplantation Institute, Icahn School of Medicine at Mount Sinai, New York City, New York, USA
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Imtiaz N, Poskus MD, Stoddard WA, Gaborski TR, Day SW. Empirical and Computational Evaluation of Hemolysis in a Microfluidic Extracorporeal Membrane Oxygenator Prototype. MICROMACHINES 2024; 15:790. [PMID: 38930760 PMCID: PMC11205701 DOI: 10.3390/mi15060790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024]
Abstract
Microfluidic devices promise to overcome the limitations of conventional hemodialysis and oxygenation technologies by incorporating novel membranes with ultra-high permeability into portable devices with low blood volume. However, the characteristically small dimensions of these devices contribute to both non-physiologic shear that could damage blood components and laminar flow that inhibits transport. While many studies have been performed to empirically and computationally study hemolysis in medical devices, such as valves and blood pumps, little is known about blood damage in microfluidic devices. In this study, four variants of a representative microfluidic membrane-based oxygenator and two controls (positive and negative) are introduced, and computational models are used to predict hemolysis. The simulations were performed in ANSYS Fluent for nine shear stress-based parameter sets for the power law hemolysis model. We found that three of the nine tested parameters overpredict (5 to 10×) hemolysis compared to empirical experiments. However, three parameter sets demonstrated higher predictive accuracy for hemolysis values in devices characterized by low shear conditions, while another three parameter sets exhibited better performance for devices operating under higher shear conditions. Empirical testing of the devices in a recirculating loop revealed levels of hemolysis significantly lower (<2 ppm) than the hemolysis ranges observed in conventional oxygenators (>10 ppm). Evaluating the model's ability to predict hemolysis across diverse shearing conditions, both through empirical experiments and computational validation, will provide valuable insights for future micro ECMO device development by directly relating geometric and shear stress with hemolysis levels. We propose that, with an informed selection of hemolysis parameters based on the shear ranges of the test device, computational modeling can complement empirical testing in the development of novel high-flow blood-contacting microfluidic devices, allowing for a more efficient iterative design process. Furthermore, the low device-induced hemolysis measured in our study at physiologically relevant flow rates is promising for the future development of microfluidic oxygenators and dialyzers.
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Affiliation(s)
- Nayeem Imtiaz
- Rochester Institute of Technology, Kate Gleason College of Engineering, Rochester, NY 14623, USA; (N.I.); (W.A.S.); (T.R.G.)
| | - Matthew D. Poskus
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA;
| | - William A. Stoddard
- Rochester Institute of Technology, Kate Gleason College of Engineering, Rochester, NY 14623, USA; (N.I.); (W.A.S.); (T.R.G.)
| | - Thomas R. Gaborski
- Rochester Institute of Technology, Kate Gleason College of Engineering, Rochester, NY 14623, USA; (N.I.); (W.A.S.); (T.R.G.)
| | - Steven W. Day
- Rochester Institute of Technology, Kate Gleason College of Engineering, Rochester, NY 14623, USA; (N.I.); (W.A.S.); (T.R.G.)
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Parker LP, Svensson Marcial A, Brismar TB, Broman LM, Prahl Wittberg L. In silico parametric analysis of femoro-jugular venovenous ECMO and return cannula dynamics: In silico analysis of femoro-jugular VV ECMO. Med Eng Phys 2024; 125:104126. [PMID: 38508803 DOI: 10.1016/j.medengphy.2024.104126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 02/05/2024] [Accepted: 02/16/2024] [Indexed: 03/22/2024]
Abstract
BACKGROUND Increasingly, computational fluid dynamics (CFD) is helping explore the impact of variables like: cannula design/size/position/flow rate and patient physiology on venovenous (VV) extracorporeal membrane oxygenation (ECMO). Here we use a CFD model to determine what role cardiac output (CO) plays and to analyse return cannula dynamics. METHODS Using a patient-averaged model of the right atrium and venae cava, we virtually inserted a 19Fr return cannula and a 25Fr drainage cannula. Running large eddy simulations, we assessed cardiac output at: 3.5-6.5 L/min and ECMO flow rate at: 2-6 L/min. We analysed recirculation fraction (Rf), time-averaged wall shear stress (TAWSS), pressure, velocity, and turbulent kinetic energy (TKE) and extracorporeal flow fraction (EFF = ECMO flow rate/CO). RESULTS Increased ECMO flow rate and decreased CO (high EFF) led to increased Rf (R = 0.98, log fit). Negative pressures developed in the venae cavae at low CO and high ECMO flow (high CR). Mean return cannula TAWSS was >10 Pa for all ECMO flow rates, with majority of the flow exiting the tip (94.0-95.8 %). CONCLUSIONS Our results underpin the strong impact of CO on VV ECMO. A simple metric like EFF, once supported by clinical data, might help predict Rf for a patient at a given ECMO flow rate. The return cannula imparts high shear stresses on the blood, largely a result of the internal diameter.
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Affiliation(s)
- Louis P Parker
- FLOW, Department of Engineering Mechanics, Royal Institute of Technology, KTH, Stockholm, Sweden
| | - Anders Svensson Marcial
- Department of Clinical Science, Intervention and Technology, Karolinska Institute, Division of Medical Imaging and Technology, Stockholm, Sweden; Department of Radiology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden
| | - Torkel B Brismar
- Department of Clinical Science, Intervention and Technology, Karolinska Institute, Division of Medical Imaging and Technology, Stockholm, Sweden; Department of Radiology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden
| | - Lars Mikael Broman
- ECMO Centre Karolinska, Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Lisa Prahl Wittberg
- FLOW, Department of Engineering Mechanics, Royal Institute of Technology, KTH, Stockholm, Sweden.
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Fiusco F, Lemétayer J, Broman LM, Prahl Wittberg L. Effect of flow rate ratio and positioning on a lighthouse tip ECMO return cannula. Biomech Model Mechanobiol 2023; 22:1891-1899. [PMID: 37454305 PMCID: PMC10613146 DOI: 10.1007/s10237-023-01741-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
Extracorporeal membrane oxygenation is a life-saving support therapy in the case of cardiopulmonary refractory failure. Its use is associated to complications due to the presence of artificial surfaces and supraphysiological stress conditions. Thus, knowledge of the fluid structures associated to each component can give insight into sources of blood damage. In this study, an experimentally validated numerical study of a conventional lighthouse tip cannula in return configuration was carried out to characterize the flow structures using water or a Newtonian blood analog with different flow rate ratios and cannula positioning and their influence on hemolysis. The results showed that strong shear layers developed where the jets from the side holes met the co-flow. Stationary backflow regions at the vessel wall were also present downstream of the cannula. In the tilted case, the recirculation was much more pronounced on the wide side and almost absent on the narrow side. Small vortical backflow structures developed at the side holes which behaved like obstacles to the co-flow, creating pairs of counter-rotating vortices, which induced locally higher risk of hemolysis. However, global hemolysis index did not show significant deviations. Across the examined flow rate ratios, the holes on the narrow side consistently reinfused a larger fraction of fluid. A radial force developed in the tilted case in a direction so as to recenter the cannula in the vessel.
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Affiliation(s)
- Francesco Fiusco
- FLOW, Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden.
| | - Julien Lemétayer
- FLOW, Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Lars Mikael Broman
- ECMO Centre Karolinska, Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Lisa Prahl Wittberg
- FLOW, Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden
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Fiusco F, Rorro F, Broman LM, Prahl Wittberg L. Numerical and experimental investigation of a lighthouse tip drainage cannula used in extracorporeal membrane oxygenation. Artif Organs 2023; 47:330-341. [PMID: 36227654 PMCID: PMC10092507 DOI: 10.1111/aor.14421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/31/2022] [Accepted: 10/05/2022] [Indexed: 02/03/2023]
Abstract
BACKGROUND Extracorporeal membrane oxygenation is a life-saving therapy used in case of acute respiratory/circulatory failure. Exposure of blood to non-physiological surfaces and high shear stresses is related to hemolytic damage and platelet activation. A detailed knowledge of the fluid dynamics of the components under different scenarios is thus paramount to assess the thrombogenicity of the circuit. METHODS An investigation of the flow structures developing in a conventional lighthouse tip (single-staged) drainage cannula was performed with cross-validated computational fluid dynamics and particle image velocimetry. The aim was to quantify the variation in drainage performance and stress levels induced by different fluid models, hematocrit and vessel-to-cannula flow rate ratios. RESULTS The results showed that the 90° bends of the flow through the side holes created a recirculation zone inside the cannula which increased residence time. Flow structures resembling a jet in a crossflow were also observed. The use of different hematocrits did not significantly affect drainage performances. The most proximal set of holes drained the largest fraction of fluid. However, different flow rate ratios altered the flow rate drained through the tip. The use of 2D data led to a 50% underestimation of shear rate levels. In the drainage zone the non-Newtonian behavior of blood was less relevant. CONCLUSIONS The most proximal holes drained the largest amount of fluid. The flow features and distribution of flow rates among the holes showed little dependence on the hematocrit. The non-Newtonian behavior of blood had a small influence on the dynamics of the flow.
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Affiliation(s)
- Francesco Fiusco
- FLOW, Department of Engineering Mechanics, KTH, Stockholm, Sweden
| | - Federico Rorro
- FLOW, Department of Engineering Mechanics, KTH, Stockholm, Sweden
| | - Lars Mikael Broman
- ECMO Centre Karolinska, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Patient-Specific Computational Modeling of Different Cannulation Strategies for Extracorporeal Membrane Oxygenation. ASAIO J 2022; 68:e179-e187. [PMID: 36326700 DOI: 10.1097/mat.0000000000001819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Institution of extracorporeal membrane oxygenation (ECMO) results in unique blood flow characteristics to the end-organ vascular beds. We studied the interplay between cardiac-driven and extracorporeal membrane oxygenation (ECMO)-driven flow to vascular beds in different ECMO configurations using a patient-specific computational fluid dynamics (CFD) analysis. A computational ECMO model (femoral artery cannulation [FAC]) was constructed using patient-specific imaging and hemodynamic data. Following model calibration, we augmented the 3D geometrical model to represent alternative ECMO configurations (ascending aorta cannulation [AAC] and subclavian artery cannulation [SAC]). We performed CFD analyses, including a novel virtual color-dye analysis to compare global and regional blood flow and pressure characteristics as well as contributions of cardiac and ECMO-derived flow to the various vascular beds. Flow waveforms at all the aortic branch vessels were pulsatile, despite low cardiac output and predominant nonpulsatile ECMO-driven hemodynamics. Virtual color-dye analysis revealed differential contribution of cardiac and ECMO-derived flow to the end-organ vascular beds in the FAC model, while this was more evenly distributed in the AAC and SAC models. While global hemodynamics were relatively similar between various ECMO configurations, several distinct hemodynamic indices, in particular wall shear stress and oscillatory shear patterns, as well as differential contribution of ECMO-derived flow to various vascular beds, showed remarkable differences. The clinical impact of this study highlighting the relevance of CFD modeling in assessment of complex hemodynamics in ECMO warrants further evaluation.
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Fisser C, Palmér O, Sallisalmi M, Paulus M, Foltan M, Philipp A, Malfertheiner MV, Lubnow M, Müller T, Broman LM. Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial. Front Med (Lausanne) 2022; 9:973240. [PMID: 36117961 PMCID: PMC9470851 DOI: 10.3389/fmed.2022.973240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundRecirculation is a common problem in venovenous (VV) extracorporeal membrane oxygenation (ECMO). The aims of this study were to compare recirculation fraction (Rf) between femoro-jugular and jugulo-femoral VV ECMO configurations, to identify risk factors for recirculation and to assess the impact on hemolysis.MethodsPatients in the medical intensive care unit (ICU) at the University Medical Center Regensburg, Germany receiving VV ECMO with femoro-jugular, and jugulo-femoral configuration at the ECMO Center Karolinska, Sweden, were included in this non-randomized prospective study. Total ECMO flow (QEC), recirculated flow (QREC), and recirculation fraction Rf = QREC/QEC were determined using ultrasound dilution technology. Effective ECMO flow (QEFF) was defined as QEFF = QEC * (1–Rf). Demographics, cannula specifics, and markers of hemolysis were assessed. Survival was evaluated at discharge from ICU.ResultsThirty-seven patients with femoro-jugular configuration underwent 595 single-point measurements and 18 patients with jugulo-femoral configuration 231 measurements. Rf was lower with femoro-jugular compared to jugulo-femoral configuration [5 (0, 11) vs. 19 (13, 28) %, respectively (p < 0.001)], resulting in similar QEFF [2.80 (2.21, 3.39) vs. 2.79 (2.39, 3.08) L/min (p = 0.225)] despite lower QEC with femoro-jugular configuration compared to jugulo-femoral [3.01 (2.40, 3.70) vs. 3.57 (3.05, 4.06) L/min, respectively (p < 0.001)]. In multivariate regression analysis, the type of configuration, distance between the two cannula tips, ECMO flow, and heart rate were significantly associated with Rf [B (95% CI): 25.8 (17.6, 33.8), p < 0.001; 960.4 (960.7, 960.1), p = 0.009; 4.2 (2.5, 5.9), p < 0.001; 960.1 (960.2, 0.0), p = 0.027]. Hemolysis was similar in subjects with Rf > 8 vs. ≤ 8%. Explorative data on survival showed comparable results in the femoro-jugular and the jugulo-femoral group (81 vs. 72%, p = 0.455).ConclusionVV ECMO with femoro-jugular configuration caused less recirculation. Further risk factors for higher Rf were shorter distance between the two cannula tips, higher ECMO flow, and lower heart rate. Rf did not affect hemolysis.
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Affiliation(s)
- Christoph Fisser
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
- *Correspondence: Christoph Fisser
| | - Oscar Palmér
- ECMO Centre Karolinska, Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
| | - Marko Sallisalmi
- ECMO Centre Karolinska, Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
| | - Michael Paulus
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Maik Foltan
- Department of Cardiothoracic Surgery, University Medical Center Regensburg, Regensburg, Germany
| | - Alois Philipp
- Department of Cardiothoracic Surgery, University Medical Center Regensburg, Regensburg, Germany
| | | | - Matthias Lubnow
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Thomas Müller
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany
| | - Lars Mikael Broman
- ECMO Centre Karolinska, Pediatric Perioperative Medicine and Intensive Care, Karolinska University Hospital, Stockholm, Sweden
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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