Pub Date : 2024-09-23DOI: 10.1177/03913988241262911
Fangqun Wang, Fan Xu, Fenglian Zhu, Shaojun Wang, Chenyang He, Litao Ding, Mengping Li
The main challenges of Biventricular Assist Devices (BiVAD) as a treatment modality for patients with Bicardiac heart failure heart failure are the balance of systemic blood flow during changes in physiological activity and the prevention of ventricular suction. In this study, a model of the Biventricular Circulatory System (BCS) was constructed and a physiological combination controller based on Starling-Like controller and Sliding Mode Controller (SMC) was proposed. The effects of the physiological controller on the hemodynamics of the BCS were investigated by simulating two sets of physiological state change experiments: elevated pulmonary artery resistance and resting-exercise, with constant speed (CS) control and combined Starling-like and PI control (SL-PI) as controllers. Simulation and experimental results showed that the Starling-like and Sliding Mode Control (SL-SMC) physiological combination controller was effective in preventing the occurrence of ventricular suction, providing higher cardiac output, maintain balance of systemic blood flow, and have higher response speed and robustness in the face of physiological state changes.
双心室辅助装置(BiVAD)作为双心室心力衰竭患者的一种治疗方式,其主要挑战在于生理活动变化时全身血流的平衡和防止心室抽吸。本研究构建了双心室循环系统(BCS)模型,并提出了基于斯塔林样控制器和滑动模式控制器(SMC)的生理组合控制器。通过模拟肺动脉阻力升高和静息-运动两组生理状态变化实验,研究了生理控制器对 BCS 血液动力学的影响,控制器分别为恒速(CS)控制器和类 Starling 控制器与 PI 控制器组合(SL-PI)控制器。仿真和实验结果表明,类星凌和滑模控制(SL-SMC)生理组合控制器能有效防止心室抽吸的发生,提供更高的心输出量,维持全身血流平衡,并在生理状态变化时具有更高的响应速度和鲁棒性。
{"title":"Performance study of dual heart assisted control system based on SL-SMC physiological combination controller.","authors":"Fangqun Wang, Fan Xu, Fenglian Zhu, Shaojun Wang, Chenyang He, Litao Ding, Mengping Li","doi":"10.1177/03913988241262911","DOIUrl":"https://doi.org/10.1177/03913988241262911","url":null,"abstract":"<p><p>The main challenges of Biventricular Assist Devices (BiVAD) as a treatment modality for patients with Bicardiac heart failure heart failure are the balance of systemic blood flow during changes in physiological activity and the prevention of ventricular suction. In this study, a model of the Biventricular Circulatory System (BCS) was constructed and a physiological combination controller based on Starling-Like controller and Sliding Mode Controller (SMC) was proposed. The effects of the physiological controller on the hemodynamics of the BCS were investigated by simulating two sets of physiological state change experiments: elevated pulmonary artery resistance and resting-exercise, with constant speed (CS) control and combined Starling-like and PI control (SL-PI) as controllers. Simulation and experimental results showed that the Starling-like and Sliding Mode Control (SL-SMC) physiological combination controller was effective in preventing the occurrence of ventricular suction, providing higher cardiac output, maintain balance of systemic blood flow, and have higher response speed and robustness in the face of physiological state changes.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142286392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1177/03913988241274735
Maria Kislikova, Almudena Vega, Eduardo Verde, Soraya Abad, Marco Vaca, Adriana Acosta, Angela González, Arturo Bascuñana, Antonia Mijailova, Coraima Nava, Miguel Villa, Juan Carlos Ruiz, Marian Goicoechea
Introduction: New dialysis membranes with new properties are being developed to improve efficacy and tolerance. The hemocompatibility of a polymeric biomaterial is influenced by the layer of water at the blood membrane interface. The new dialyzer TORAY NV-U® has a membrane Hydrolink™, designed to suppress platelet adhesion and to improve the hemocompatibility. Until now, there is no experience in online hemodiafiltration (OL-HDF).The objective of the present study is to evaluate the efficacy of this new membrane in OL-HDF therapy compared to another membrane commonly used. Other objectives are to evaluate the inflammatory response, hemodynamic tolerance, and the anticoagulation regimes.
Methods: This is a prospective pilot study performed in five anuric patients receiving OL-HDF. For 1 month patients were kept with their usual dialyzer FX1000® (FMC). Subsequently, the dialyzer was changed to TORAY NV-U® (Hydrolink®) for 1 month. In the last dialysis session of each dialyzer, blood tests were performed to evaluate inflammation and depurative capacity.
Results: We did not find differences in medium size removal molecules and convective volume: FX1000®: 31 ± 9 l per session and Hydrolink™ 30 ± 8 l; p = 0.7); β2microglobulin reduction ratio (RR) FX1000® FMC 83 ± 3%; Hydrolink™ 79 ± 4; p = 0.14; Myoglobin RR FX1000® FMC 72 ± 7%; Hydrolink™ 76 ± 4; p = 0.28. We did not find differences in inflammation parameters: serum IL6 with FX1000® 6.0 ± 4.2 pg/mL; Hydrolink™ 7.6 ± 5.0 pg/mL; p = 0.3.During all sessions with the two dialyzers there was adequate plasmatic filling, reaching 85 % filling. All patients had "good" dialyzer status in all dialysis sessions with TORAY NV-U®, while the dialyzer status with FX1000® was "good" in 20% of the sessions, "medium" in 30%, and "dirty" in the remaining 50% dialysis sessions.
Conclusions: The new dialyzer Hydrolink™, TORAY NV-U® is not inferior to perform OL-HDF compared to dialyzers usually used for this therapy, and could allow decrease heparin doses. Further studies with a bigger sample size and longer follow-up will answer if Hydrolink improves inflammation and assess a better hemodynamic tolerance.
{"title":"Depurative capacity toward medium molecules of the dialyzer Toray NV-U<sup>®</sup> Hydrolink™: A new hydrophilic membrane to perform online hemodiafiltration.","authors":"Maria Kislikova, Almudena Vega, Eduardo Verde, Soraya Abad, Marco Vaca, Adriana Acosta, Angela González, Arturo Bascuñana, Antonia Mijailova, Coraima Nava, Miguel Villa, Juan Carlos Ruiz, Marian Goicoechea","doi":"10.1177/03913988241274735","DOIUrl":"https://doi.org/10.1177/03913988241274735","url":null,"abstract":"<p><strong>Introduction: </strong>New dialysis membranes with new properties are being developed to improve efficacy and tolerance. The hemocompatibility of a polymeric biomaterial is influenced by the layer of water at the blood membrane interface. The new dialyzer TORAY NV-U<sup>®</sup> has a membrane Hydrolink™, designed to suppress platelet adhesion and to improve the hemocompatibility. Until now, there is no experience in online hemodiafiltration (OL-HDF).The objective of the present study is to evaluate the efficacy of this new membrane in OL-HDF therapy compared to another membrane commonly used. Other objectives are to evaluate the inflammatory response, hemodynamic tolerance, and the anticoagulation regimes.</p><p><strong>Methods: </strong>This is a prospective pilot study performed in five anuric patients receiving OL-HDF. For 1 month patients were kept with their usual dialyzer FX1000<sup>®</sup> (FMC). Subsequently, the dialyzer was changed to TORAY NV-U<sup>®</sup> (Hydrolink<sup>®</sup>) for 1 month. In the last dialysis session of each dialyzer, blood tests were performed to evaluate inflammation and depurative capacity.</p><p><strong>Results: </strong>We did not find differences in medium size removal molecules and convective volume: FX1000<sup>®</sup>: 31 ± 9 l per session and Hydrolink™ 30 ± 8 l; <i>p</i> = 0.7); β2microglobulin reduction ratio (RR) FX1000<sup>®</sup> FMC 83 ± 3%; Hydrolink™ 79 ± 4; <i>p</i> = 0.14; Myoglobin RR FX1000<sup>®</sup> FMC 72 ± 7%; Hydrolink™ 76 ± 4; <i>p</i> = 0.28. We did not find differences in inflammation parameters: serum IL6 with FX1000<sup>®</sup> 6.0 ± 4.2 pg/mL; Hydrolink™ 7.6 ± 5.0 pg/mL; <i>p</i> = 0.3.During all sessions with the two dialyzers there was adequate plasmatic filling, reaching 85 % filling. All patients had \"good\" dialyzer status in all dialysis sessions with TORAY NV-U<sup>®</sup>, while the dialyzer status with FX1000<sup>®</sup> was \"good\" in 20% of the sessions, \"medium\" in 30%, and \"dirty\" in the remaining 50% dialysis sessions.</p><p><strong>Conclusions: </strong>The new dialyzer Hydrolink™, TORAY NV-U<sup>®</sup> is not inferior to perform OL-HDF compared to dialyzers usually used for this therapy, and could allow decrease heparin doses. Further studies with a bigger sample size and longer follow-up will answer if Hydrolink improves inflammation and assess a better hemodynamic tolerance.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142286391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-19DOI: 10.1177/03913988241267797
Joseph Bornoff, Shaikh Faisal Zaman, Azad Najar, Thomas Finocchiaro, Ina Laura Perkins, Andrew N Cookson, Katharine H Fraser
The assessment and reduction of haemolysis within mechanical circulatory support (MCS) remains a concern with regard to device safety and regulatory approval. Numerical methods for predicting haemolysis have typically been applied to rotary MCS devices and the extent to which these methods apply to positive-displacement MCS is unclear. The aim of this study was to evaluate the suitability of these methods for assessing haemolysis in positive-displacement blood pumps. Eulerian scalar-transport and Lagrangian particle-tracking approaches derived from the shear-based power-law relationship were used to calculate haemolysis in a computational fluid dynamics model of the Realheart total artificial heart. A range of power-law constants and their effect on simulated haemolysis were also investigated. Both Eulerian and Lagrangian methods identified the same key mechanism of haemolysis: leakage flow through the bileaflet valves. Whilst the magnitude of haemolysis varied with different power-law constants, the method of haemolysis generation remained consistent. The Eulerian method was more robust and reliable at identifying sites of haemolysis generation, as it was able to capture the persistent leakage flow throughout the entire pumping cycle. This study paves the way for different positive-displacement MCS devices to be compared across different operating conditions, enabling the optimisation of these pumps for improved patient outcomes.
{"title":"Assessment of haemolysis models for a positive-displacement total artificial heart.","authors":"Joseph Bornoff, Shaikh Faisal Zaman, Azad Najar, Thomas Finocchiaro, Ina Laura Perkins, Andrew N Cookson, Katharine H Fraser","doi":"10.1177/03913988241267797","DOIUrl":"https://doi.org/10.1177/03913988241267797","url":null,"abstract":"<p><p>The assessment and reduction of haemolysis within mechanical circulatory support (MCS) remains a concern with regard to device safety and regulatory approval. Numerical methods for predicting haemolysis have typically been applied to rotary MCS devices and the extent to which these methods apply to positive-displacement MCS is unclear. The aim of this study was to evaluate the suitability of these methods for assessing haemolysis in positive-displacement blood pumps. Eulerian scalar-transport and Lagrangian particle-tracking approaches derived from the shear-based power-law relationship were used to calculate haemolysis in a computational fluid dynamics model of the Realheart total artificial heart. A range of power-law constants and their effect on simulated haemolysis were also investigated. Both Eulerian and Lagrangian methods identified the same key mechanism of haemolysis: leakage flow through the bileaflet valves. Whilst the magnitude of haemolysis varied with different power-law constants, the method of haemolysis generation remained consistent. The Eulerian method was more robust and reliable at identifying sites of haemolysis generation, as it was able to capture the persistent leakage flow throughout the entire pumping cycle. This study paves the way for different positive-displacement MCS devices to be compared across different operating conditions, enabling the optimisation of these pumps for improved patient outcomes.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142286390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1177/03913988241268067
Vincenz Crone, Mario Hahne, Finn Knüppel, Frank-Hendrik Wurm, Benjamin Torner
Medical advancements, particularly in ventricular assist devices (VADs), have notably advanced heart failure (HF) treatment, improving patient outcomes. However, challenges such as adverse events (strokes, bleeding and thrombosis) persist. Computational fluid dynamics (CFD) simulations are instrumental in understanding VAD flow dynamics and the associated flow-induced adverse events resulting from non-physiological flow conditions in the VAD.This study aims to validate critical CFD simulation parameters for accurate VAD simulations interacting with the cardiovascular system, building upon the groundwork laid by Hahne et al. A bidirectional coupling technique was used to model dynamic (pulsatile) flow conditions of the VAD CFD interacting with the cardiovascular system. Mesh size, time steps and simulation method (URANS, LES) were systematically varied to evaluate their impact on the dynamic pump performance (dynamic curve) of the HeartMate 3, aiming to find the optimal simulation configuration for accurately reproduce the dynamic curve. The new Overlapping Ratio (OR) method was developed and applied to quantify dynamic curves.In particular, mesh and time step sizes were found to have the greatest influence on the calculated pump performance. Therefore, small time steps and large mesh sizes are recommended to obtain accurate dynamic curves. On the other hand, the influence of the simulation method was not significant in this study. This study contributes to advancing VAD simulations, ultimately enhancing clinical efficacy and patient outcomes.
医学的进步,尤其是心室辅助装置(VAD)的进步,显著推进了心力衰竭(HF)的治疗,改善了患者的预后。然而,不良事件(中风、出血和血栓)等挑战依然存在。计算流体动力学(CFD)模拟有助于了解 VAD 的流动动力学以及 VAD 中非生理流动条件导致的相关流动诱发不良事件。本研究旨在 Hahne 等人奠定的基础上,验证关键 CFD 模拟参数,以准确模拟与心血管系统相互作用的 VAD。系统地改变了网格大小、时间步长和模拟方法(URANS、LES),以评估它们对 HeartMate 3 动态泵性能(动态 H-Q 曲线)的影响,目的是找到精确再现动态 H-Q 曲线的最佳模拟配置。开发并应用了新的重叠率(OR)方法来量化动态 H-Q 曲线。因此,建议采用小时间步长和大网格尺寸来获得精确的动态 H-Q 曲线。另一方面,本研究中模拟方法的影响并不显著。这项研究有助于推进 VAD 模拟,最终提高临床疗效和患者预后。
{"title":"Dynamic VAD simulations: Performing accurate simulations of ventricular assist devices in interaction with the cardiovascular system.","authors":"Vincenz Crone, Mario Hahne, Finn Knüppel, Frank-Hendrik Wurm, Benjamin Torner","doi":"10.1177/03913988241268067","DOIUrl":"https://doi.org/10.1177/03913988241268067","url":null,"abstract":"<p><p>Medical advancements, particularly in ventricular assist devices (VADs), have notably advanced heart failure (HF) treatment, improving patient outcomes. However, challenges such as adverse events (strokes, bleeding and thrombosis) persist. Computational fluid dynamics (CFD) simulations are instrumental in understanding VAD flow dynamics and the associated flow-induced adverse events resulting from non-physiological flow conditions in the VAD.This study aims to validate critical CFD simulation parameters for accurate VAD simulations interacting with the cardiovascular system, building upon the groundwork laid by Hahne et al. A bidirectional coupling technique was used to model dynamic (pulsatile) flow conditions of the VAD CFD interacting with the cardiovascular system. Mesh size, time steps and simulation method (URANS, LES) were systematically varied to evaluate their impact on the dynamic pump performance (dynamic <math><mrow><mi>H</mi><mo>-</mo><mi>Q</mi></mrow></math> curve) of the HeartMate 3, aiming to find the optimal simulation configuration for accurately reproduce the dynamic <math><mrow><mi>H</mi><mo>-</mo><mi>Q</mi></mrow></math> curve. The new Overlapping Ratio (OR) method was developed and applied to quantify dynamic <math><mrow><mi>H</mi><mo>-</mo><mi>Q</mi></mrow></math> curves.In particular, mesh and time step sizes were found to have the greatest influence on the calculated pump performance. Therefore, small time steps and large mesh sizes are recommended to obtain accurate dynamic <math><mrow><mi>H</mi><mo>-</mo><mi>Q</mi></mrow></math> curves. On the other hand, the influence of the simulation method was not significant in this study. This study contributes to advancing VAD simulations, ultimately enhancing clinical efficacy and patient outcomes.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142139998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: We investigated whether the condition of the inner surface of hollow fibers affects the blood compatibility of hemodialyzers.
Methods: We used scanning probe microscope/atomic force microscopy (SPM/AFM) to investigate the height of the swelling and flexible layers (thickness and softness) on the inner surfaces of the hollow fibers. Next, we tested the blood compatibility between dialyzers comprising a hollow fiber membrane, in which the other dialyzers, except for PVP, were additionally coated using PS membranes coated with other materials. After blood was injected into the dialyzer and plugged, dynamic stimulation was performed by slightly rotating the dialyzer for 4 h, although there was no blood circulation.
Results: The vitamin E-coated polysulfone (PS) membrane showed a higher thickness and softness of the flexible layer than the asymmetric cellulose triacetate membrane without polyvinylpyrrolidone (PVP) and the PS membranes with PVP. We found that the dialyzer with vitamin E coating significantly suppressed the decrease in platelets, increase in β-TG, and increase in PF4 compared to those coated with NV polymer. Additionally, as the adsorbed protein on the inner surface, the total protein, fibronectin, and vWF levels were significantly lower in the vitamin E-coated dialyzer.
Conclusion: The thickness and softness of the flexible layer of the inner surface of the hollow fiber membrane in vitro affect differences in blood coagulation performance in clinical research. Future clinical trials are required to confirm our results.
背景:我们研究了中空纤维内表面的状况是否会影响血液透析器的血液相容性:我们研究了中空纤维内表面的状况是否会影响血液透析器的血液相容性:我们使用扫描探针显微镜/原子力显微镜(SPM/AFM)研究了中空纤维内表面膨胀层和柔性层的高度(厚度和柔软度)。接下来,我们测试了由中空纤维膜组成的透析器之间的血液相容性,其中除 PVP 外,其他透析器都额外使用了涂有其他材料的 PS 膜。将血液注入透析器并堵塞后,通过轻微旋转透析器进行动态刺激,持续 4 小时,尽管没有血液循环:结果:与不含聚乙烯吡咯烷酮(PVP)的不对称三醋酸纤维素膜和含 PVP 的聚砜(PS)膜相比,涂有维生素 E 的聚砜(PS)膜显示出更高的厚度和柔性层的柔软度。我们发现,与涂有 NV 聚合物的透析器相比,涂有维生素 E 的透析器能明显抑制血小板的减少、β-TG 的增加和 PF4 的增加。此外,由于内表面吸附了蛋白质,涂有维生素 E 的透析器中的总蛋白、纤连蛋白和 vWF 水平明显降低:结论:体外中空纤维膜内表面柔性层的厚度和柔软度会影响临床研究中血液凝固性能的差异。未来的临床试验需要证实我们的结果。
{"title":"Flexible inner surface of polysulfone membranes prevents platelet adhesive protein adsorption and improves antithrombogenicity in vitro.","authors":"Ryo Takatsuji, Masahide Koremoto, Yoko Fujimoto, Yuko Saida, Yoshihiro Hatanaka","doi":"10.1177/03913988241269465","DOIUrl":"https://doi.org/10.1177/03913988241269465","url":null,"abstract":"<p><strong>Background: </strong>We investigated whether the condition of the inner surface of hollow fibers affects the blood compatibility of hemodialyzers.</p><p><strong>Methods: </strong>We used scanning probe microscope/atomic force microscopy (SPM/AFM) to investigate the height of the swelling and flexible layers (thickness and softness) on the inner surfaces of the hollow fibers. Next, we tested the blood compatibility between dialyzers comprising a hollow fiber membrane, in which the other dialyzers, except for PVP, were additionally coated using PS membranes coated with other materials. After blood was injected into the dialyzer and plugged, dynamic stimulation was performed by slightly rotating the dialyzer for 4 h, although there was no blood circulation.</p><p><strong>Results: </strong>The vitamin E-coated polysulfone (PS) membrane showed a higher thickness and softness of the flexible layer than the asymmetric cellulose triacetate membrane without polyvinylpyrrolidone (PVP) and the PS membranes with PVP. We found that the dialyzer with vitamin E coating significantly suppressed the decrease in platelets, increase in β-TG, and increase in PF4 compared to those coated with NV polymer. Additionally, as the adsorbed protein on the inner surface, the total protein, fibronectin, and vWF levels were significantly lower in the vitamin E-coated dialyzer.</p><p><strong>Conclusion: </strong>The thickness and softness of the flexible layer of the inner surface of the hollow fiber membrane in vitro affect differences in blood coagulation performance in clinical research. Future clinical trials are required to confirm our results.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142125664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-02DOI: 10.1177/03913988241269508
Gabriella Bottari, Isabella Guzzo
{"title":"How I treat rhabdomyolysis-induced AKI? A different perspective.","authors":"Gabriella Bottari, Isabella Guzzo","doi":"10.1177/03913988241269508","DOIUrl":"https://doi.org/10.1177/03913988241269508","url":null,"abstract":"","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142119744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-02DOI: 10.1177/03913988241268419
Arthur P Burns-Cox, Lian Gan, Ashraf W Khir
Background: Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability.
Aim: To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects.
Methods: A prototype pump was designed and fabricated in-house without any effort to optimise its specification. It was then tested in vitro, in terms of effect of pumping frequency, background pressure differences and pump size on output performance.
Results: Net flow rate (NFR) and maximum pressure head delivery are both reasonably linearly dependent on pumping frequency within normal physiological range. Positive linearity is also observed between NFR and the extent of asymmetric pumping. The device regulates NFR in favourable pressure head difference and overcomes significant adverse pressure head difference. Additionally, performance is shown to be insensitive to device size.
Conclusions: The feasibility of the novel rotary pump integrating impedance and peristaltic effects is demonstrated to perform in normal physiological conditions without any optimisation effort. It provides promising results for possible future paediatric cavopulmonary support and warrants further investigation of miniaturisation and possible haemolysis.
{"title":"A cavalpulmonary assist device utilising impedance pumping enhanced by peristaltic effect.","authors":"Arthur P Burns-Cox, Lian Gan, Ashraf W Khir","doi":"10.1177/03913988241268419","DOIUrl":"https://doi.org/10.1177/03913988241268419","url":null,"abstract":"<p><strong>Background: </strong>Fontan procedure, the standard surgical palliation to treat children with single ventricular defects, causes systemic complications over years due to lack of pumping at cavopulmonary junction. A device developed specifically for cavopulmonary support is thus considered, while current commercial ventricular assist devices (VAD) induce high shear rates to blood, and have issues with paediatric suitability.</p><p><strong>Aim: </strong>To demonstrate the feasibility of a small, valveless, non-invasive to blood and pulsatile rotary pump, which integrates impedance and peristaltic effects.</p><p><strong>Methods: </strong>A prototype pump was designed and fabricated in-house without any effort to optimise its specification. It was then tested in vitro, in terms of effect of pumping frequency, background pressure differences and pump size on output performance.</p><p><strong>Results: </strong>Net flow rate (NFR) and maximum pressure head delivery are both reasonably linearly dependent on pumping frequency within normal physiological range. Positive linearity is also observed between NFR and the extent of asymmetric pumping. The device regulates NFR in favourable pressure head difference and overcomes significant adverse pressure head difference. Additionally, performance is shown to be insensitive to device size.</p><p><strong>Conclusions: </strong>The feasibility of the novel rotary pump integrating impedance and peristaltic effects is demonstrated to perform in normal physiological conditions without any optimisation effort. It provides promising results for possible future paediatric cavopulmonary support and warrants further investigation of miniaturisation and possible haemolysis.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-02DOI: 10.1177/03913988241274252
Jesús Emilio Barrueco-Francioni, María Carmen Martínez-González, Juan Francisco Martínez-Carmona, María Palma Benítez-Moreno, Cesar Aragón-González, Manuel Enrique Herrera-Gutiérrez
Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.
{"title":"ECMO in severe hypoxemia post liver transplant for hepatopulmonary syndrome.","authors":"Jesús Emilio Barrueco-Francioni, María Carmen Martínez-González, Juan Francisco Martínez-Carmona, María Palma Benítez-Moreno, Cesar Aragón-González, Manuel Enrique Herrera-Gutiérrez","doi":"10.1177/03913988241274252","DOIUrl":"https://doi.org/10.1177/03913988241274252","url":null,"abstract":"<p><p>Hepatopulmonary syndrome (HPS) poses a significant challenge in liver transplant patients, affecting between 10% and 30% of candidates. Historically, HPS was considered a contraindication for liver transplantation due to its association with high mortality rates. However, recent studies have shown improvements in pulmonary function post-transplant, leading to the inclusion of these patients as candidates. Despite this progress, approximately one-fifth of liver transplant recipients develop severe postoperative hypoxia, further complicating their clinical course and contributing to increased mortality. The management of post-transplant HPS involves various strategies, including extracorporeal membrane oxygenation (ECMO), although its use remains infrequently reported. Theoretical models suggest that oxygenation typically improves within 10 days post-transplant, while resolution of HPS may take 6-12 months, making ECMO an attractive possibility as a bridge to recovery in this population. We present a case were ECMO was used in this context.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142107096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1177/03913988241269492
Siyan Tang, Yan Yu, Siwei Tang, Tong Liu, Hao Wu, Yi Liu, Lijuan Zhao, Rui Lu, Peng Zhang, Ming Bai
Background: The optimal anticoagulation regimen for continuous renal replacement therapy (CRRT) in liver failure (LF) patients without increased bleeding risk remains controversial. Therefore, we conducted a monocentric retrospective study to evaluate the efficacy and safety of the regional citrate anticoagulation (RCA) versus low molecular weight heparin (LMWH) anticoagulation for CRRT in LF without increased bleeding risk.
Method: According to the anticoagulation strategy for CRRT, patients were divided into the RCA and LMWH-anticoagulation groups. The evaluated endpoints were patient survival, filter lifespan, bleeding, citrate accumulation, and totCa/ionCa ratio.
Result: Totally 167 and 164 filters were used in the RCA and LMWH group, respectively. The median filter lifespan was significantly longer in the RCA group (34 h (IQR = 24-54) versus 24 h (IQR = 18-45.5) [95%CI, 24.5-33]; p < 0.001). The 4-week mortality rate was significantly higher in the LMWH-anticoagulation group (71 (57.72%) vs 53 (40.46%); p = 0.006). After adjusted the important parameters in the multivariate COX regression model, the mortality risk was significantly reduced in the RCA group (HR = 0.668 [95%CI, 0.468-0.955]; p = 0.027). In the LMWH group, 30 bleeding episodes (24,19%) were observed, whereas only 7 (5.34%) occurred in the RCA group (p < 0.001). Two patients (1.5%) in the RCA group occurred citrate accumulation.
Conclusions: In LF patients without increased bleeding risk who underwent CRRT, RCA significantly extended the filter lifespan and improved patient survival rate. There was no significant difference in the rate of adverse events between the two groups.
{"title":"Regional citrate anticoagulation versus LMWH anticoagulation for CRRT in liver failure patients without increased bleeding risk.","authors":"Siyan Tang, Yan Yu, Siwei Tang, Tong Liu, Hao Wu, Yi Liu, Lijuan Zhao, Rui Lu, Peng Zhang, Ming Bai","doi":"10.1177/03913988241269492","DOIUrl":"https://doi.org/10.1177/03913988241269492","url":null,"abstract":"<p><strong>Background: </strong>The optimal anticoagulation regimen for continuous renal replacement therapy (CRRT) in liver failure (LF) patients without increased bleeding risk remains controversial. Therefore, we conducted a monocentric retrospective study to evaluate the efficacy and safety of the regional citrate anticoagulation (RCA) versus low molecular weight heparin (LMWH) anticoagulation for CRRT in LF without increased bleeding risk.</p><p><strong>Method: </strong>According to the anticoagulation strategy for CRRT, patients were divided into the RCA and LMWH-anticoagulation groups. The evaluated endpoints were patient survival, filter lifespan, bleeding, citrate accumulation, and totCa/ionCa ratio.</p><p><strong>Result: </strong>Totally 167 and 164 filters were used in the RCA and LMWH group, respectively. The median filter lifespan was significantly longer in the RCA group (34 h (IQR = 24-54) versus 24 h (IQR = 18-45.5) [95%CI, 24.5-33]; <i>p</i> < 0.001). The 4-week mortality rate was significantly higher in the LMWH-anticoagulation group (71 (57.72%) vs 53 (40.46%); <i>p</i> = 0.006). After adjusted the important parameters in the multivariate COX regression model, the mortality risk was significantly reduced in the RCA group (HR = 0.668 [95%CI, 0.468-0.955]; <i>p</i> = 0.027). In the LMWH group, 30 bleeding episodes (24,19%) were observed, whereas only 7 (5.34%) occurred in the RCA group (<i>p</i> < 0.001). Two patients (1.5%) in the RCA group occurred citrate accumulation.</p><p><strong>Conclusions: </strong>In LF patients without increased bleeding risk who underwent CRRT, RCA significantly extended the filter lifespan and improved patient survival rate. There was no significant difference in the rate of adverse events between the two groups.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1177/03913988241269534
Arda Aybars Pala, Yusuf Salim Urcun, Cengiz Guven
Background: The continuity of arteriovenous fistula (AVF) patency is essential for effective hemodialysis. In the present study, we aimed to investigate the relationship between AVF patency and atherogenic index of plasma (AIP) in patients with native proximal upper-extremity AVF.
Methods: A total of 143 patients with native proximal upper-extremity AVF created in our clinic between January 2014 and April 2022 were analyzed retrospectively. Those with at least 24 months of follow-up and intact AVF were defined as "Group 1" (n = 97), and those with AVF thrombosis were defined as "Group 2" (n = 46).
Results: The primary patency rates of the patient groups included in the study were found to be 88.1% at 6th month, 79% at 12th month, and 67.8% at 24th month. The mean AIP values that were calculated in Group 2 were found to be statistically significantly higher than the mean value calculated in Group 1 (0.30 ± 0.12 vs 0.20 ± 0.10, p < 0.001). In a multivariate logistic regression analysis made to identify the predictors of proximal upper-extremity AVF thrombosis development, total cholesterol (OR [odds ratio] = 2.259, 95% CI [confidence interval] = 1.468-3.475, p < 0.001), and triglyceride (OR = 13.777, 95% CI = 3.740-50.750, p < 0.001) were identified as independent predictors.
Conclusion: A significant relationship was detected in the analyses between the easily calculated AIP values and the development of AVF thrombosis. The AIP is a remarkable preoperative parameter regarding proximal upper-extremity AVF patency.
{"title":"Evaluation of the relationship between proximal upper-extremity arteriovenous fistula patency and atherogenic index of plasma.","authors":"Arda Aybars Pala, Yusuf Salim Urcun, Cengiz Guven","doi":"10.1177/03913988241269534","DOIUrl":"https://doi.org/10.1177/03913988241269534","url":null,"abstract":"<p><strong>Background: </strong>The continuity of arteriovenous fistula (AVF) patency is essential for effective hemodialysis. In the present study, we aimed to investigate the relationship between AVF patency and atherogenic index of plasma (AIP) in patients with native proximal upper-extremity AVF.</p><p><strong>Methods: </strong>A total of 143 patients with native proximal upper-extremity AVF created in our clinic between January 2014 and April 2022 were analyzed retrospectively. Those with at least 24 months of follow-up and intact AVF were defined as \"Group 1\" (<i>n</i> = 97), and those with AVF thrombosis were defined as \"Group 2\" (<i>n</i> = 46).</p><p><strong>Results: </strong>The primary patency rates of the patient groups included in the study were found to be 88.1% at 6th month, 79% at 12th month, and 67.8% at 24th month. The mean AIP values that were calculated in Group 2 were found to be statistically significantly higher than the mean value calculated in Group 1 (0.30 ± 0.12 vs 0.20 ± 0.10, <i>p</i> < 0.001). In a multivariate logistic regression analysis made to identify the predictors of proximal upper-extremity AVF thrombosis development, total cholesterol (OR [odds ratio] = 2.259, 95% CI [confidence interval] = 1.468-3.475, <i>p</i> < 0.001), and triglyceride (OR = 13.777, 95% CI = 3.740-50.750, <i>p</i> < 0.001) were identified as independent predictors.</p><p><strong>Conclusion: </strong>A significant relationship was detected in the analyses between the easily calculated AIP values and the development of AVF thrombosis. The AIP is a remarkable preoperative parameter regarding proximal upper-extremity AVF patency.</p>","PeriodicalId":13932,"journal":{"name":"International Journal of Artificial Organs","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}