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Ye SH, Orizondo RA, De BN, Kim S, Frankowski BJ, Federspiel WJ, Wagner WR. Epoxy silane sulfobetaine block copolymers for simple, aqueous thromboresistant coating on ambulatory assist lung devices. J Biomed Mater Res A 2024; 112:99-109. [PMID: 37929658 PMCID: PMC10629844 DOI: 10.1002/jbm.a.37619] [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: 06/20/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 11/07/2023]
Abstract
Developing an ambulatory assist lung (AAL) for patients who need continuous extracorporeal membrane oxygenation has been associated with several design objectives, including the design of compact components, optimization of gas transfer efficiency, and reduced thrombogenicity. In an effort to address thrombogenicity concerns with currently utilized component biomaterials, a low molecular weight water soluble siloxane-functionalized zwitterionic sulfobetaine (SB-Si) block copolymer was coated on a full-scale AAL device set via a one pot aqueous circulation coating. All device parts including hollow fiber bundle, housing, tubing and cannular were successfully coated with increasing atomic compositions of the SB block copolymer and the coated surfaces showed a significant reduction of platelet deposition while gas exchange performance was sustained. However, water solubility of the SB-Si was unstable, and the coating method, including oxygen plasma pretreatment on the surfaces were considered inconsistent with the objective of developing a simple aqueous coating. Addressing these weaknesses, SB block copolymers were synthesized bearing epoxy or epoxy-silane groups with improved water solubility (SB-EP & SB-EP-Si) and no requirement for surface pretreatment (SB-EP-Si). An SB-EP-Si triblock copolymer showed the most robust coating capacity and stability without prior pretreatment to represent a simple aqueous circulation coating on an assembled full-scale AAL device.
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Affiliation(s)
- Sang-Ho Ye
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - Ryan A. Orizondo
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - Bianca Nina De
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - Seungil Kim
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - Brian J. Frankowski
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - William J. Federspiel
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
| | - William R. Wagner
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15219, United States
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Strudthoff LJ, Hesselmann F, Clauser JC, Arens J. Refurbishment of Extracorporeal Life Support Oxygenators in the Context of In Vitro Testing. ASAIO J 2023; 69:924-931. [PMID: 37314830 DOI: 10.1097/mat.0000000000001999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
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.
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Affiliation(s)
- Lasse J Strudthoff
- From the Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Felix Hesselmann
- From the Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Enmodes GmbH, Aachen, Germany
| | - Johanna C Clauser
- From the Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Jutta Arens
- From the Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Aachen, Germany
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Fallon BP, Thompson AJ, Prater AR, Buchan S, Alberts T, Hoenerhoff M, Rojas-Pena A, Bartlett RH, Hirschl RB. Seven-day in vivo testing of a novel, low-resistance, pumpless pediatric artificial lung for long-term support. J Pediatr Surg 2022; 57:614-623. [PMID: 35953340 PMCID: PMC10112847 DOI: 10.1016/j.jpedsurg.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/31/2022] [Accepted: 07/06/2022] [Indexed: 12/01/2022]
Abstract
INTRODUCTION For children with end-stage lung disease that cannot wean from extracorporeal life support (ECLS), a wearable artificial lung would permit extubation and provide a bridge to recovery or transplantation. We evaluate the function of the novel Pediatric MLung-a low-resistance, pumpless artificial lung developed specifically for children-in healthy animal subjects. METHODS Adolescent "mini sheep" weighing 12-20 kg underwent left thoracotomy, cannulation of the main pulmonary artery (PA; inflow) and left atrium (outflow), and connection to the MLung. RESULTS Thirteen sheep were studied; 6 were supported for 7 days. Mean PA pressure was 23.9 ± 6.9 mmHg. MLung blood flow was 633±258 mL/min or 30.0 ± 16.0% of CO. MLung pressure drop was 4.4 ± 3.4 mmHg. Resistance was 7.2 ± 5.2 mmHg/L/min. Device outlet oxygen saturation was 99.0 ± 3.3% with inlet saturation 53.8 ± 7.3%. Oxygen delivery was 41.1 ± 18.4 mL O2/min (maximum 84.9 mL/min) or 2.8 ± 1.5 mL O2/min/kg. Platelet count significantly decreased; no platelet transfusions were required. Plasma free hemoglobin significantly increased only on day 7, at which point 2 of the animals had plasma free hemoglobin levels above 50 mg/dL. CONCLUSION The MLung provides adequate gas exchange at appropriate blood flows for the pediatric population in a PA-to-LA configuration. Further work remains to improve the biocompatibility of the device. LEVEL OF EVIDENCE N/A.
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Affiliation(s)
- Brian P Fallon
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Alex J Thompson
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Aaron R Prater
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Skylar Buchan
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Trevor Alberts
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Mark Hoenerhoff
- In Vivo Animal Core, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Alvaro Rojas-Pena
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA; Department of Surgery, Section of Transplant Surgery, Michigan Medicine, Ann Arbor, MI, USA
| | - Robert H Bartlett
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Ronald B Hirschl
- Department of Surgery, Extracorporeal Life Support Laboratory, Michigan Medicine, B560 MSRB II/SPC 5686, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA; Department of Surgery, Section of Pediatric Surgery, Michigan Medicine, Ann Arbor, MI, USA
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Orizondo RA, Omecinski KS, May AG, Dhamotharan V, Frankowski BJ, Burgreen GW, Ye SH, Kocyildirim E, Sanchez PG, D’Cunha J, Wagner WR, Federspiel WJ. Month-long Respiratory Support by a Wearable Pumping Artificial Lung in an Ovine Model. Transplantation 2021; 105:999-1007. [PMID: 33031226 PMCID: PMC8024407 DOI: 10.1097/tp.0000000000003481] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND A wearable artificial lung could improve lung transplantation outcomes by easing implementation of physical rehabilitation during long-term pretransplant respiratory support. The Modular Extracorporeal Lung Assist System (ModELAS) is a compact pumping artificial lung currently under development. This study evaluated the long-term in vivo performance of the ModELAS during venovenous support in awake sheep. Feedback from early trials and computational fluid dynamic analysis guided device design optimization along the way. METHODS The ModELAS was connected to healthy sheep via a dual-lumen cannula in the jugular vein. Sheep were housed in a fixed-tether pen while wearing the device in a holster during support. Targeted blood flow rate and support duration were 2-2.5 L/min and 28-30 days, respectively. Anticoagulation was maintained via systemic heparin. Device pumping and gas exchange performance and hematologic indicators of sheep physiology were measured throughout support. RESULTS Computational fluid dynamic-guided design modifications successfully decreased pump thrombogenicity from initial designs. For the optimized design, 4 of 5 trials advancing past early perioperative and cannula-related complications lasted the full month of support. Blood flow rate and CO2 removal in these trials were 2.1 ± 0.3 L/min and 139 ± 15 mL/min, respectively, and were stable during support. One trial ended after 22 days of support due to intradevice thrombosis. Support was well tolerated by the sheep with no signs of hemolysis or device-related organ impairment. CONCLUSIONS These results demonstrate the ability of the ModELAS to provide safe month-long support without consistent deterioration of pumping or gas exchange capabilities.
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Affiliation(s)
- Ryan A. Orizondo
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Medicine, University of Pittsburgh
- Department of Bioengineering, University of Pittsburgh
| | - Katelin S. Omecinski
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Bioengineering, University of Pittsburgh
| | - Alexandra G. May
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Chemical and Petroleum Engineering, University of Pittsburgh
| | - Vishaal Dhamotharan
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Bioengineering, University of Pittsburgh
| | | | - Greg W. Burgreen
- Computational Fluid Dynamics Group, Center for Advanced Vehicular Systems, Mississippi State University
| | - Sang-Ho Ye
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Surgery, University of Pittsburgh
| | - Ergin Kocyildirim
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Cardiothoracic Surgery, Children’s Hospital of Pittsburgh
| | - Pablo G. Sanchez
- Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center
| | - Jonathan D’Cunha
- Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center
| | - William R. Wagner
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Bioengineering, University of Pittsburgh
- Department of Chemical and Petroleum Engineering, University of Pittsburgh
- Department of Surgery, University of Pittsburgh
| | - William J. Federspiel
- McGowan Institute for Regenerative Medicine, University of Pittsburgh
- Department of Bioengineering, University of Pittsburgh
- Department of Chemical and Petroleum Engineering, University of Pittsburgh
- Department of Critical Care Medicine, University of Pittsburgh Medical Center
- Clinical and Translational Science Institute, University of Pittsburgh
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Abstract
Children with end-stage lung failure awaiting lung transplant would benefit from improvements in artificial lung technology allowing for wearable pulmonary support as a bridge-to-transplant therapy. In this work, we designed, fabricated, and tested the Pediatric MLung-a dual-inlet hollow fiber artificial lung based on concentric gating, which has a rated flow of 1 L/min, and a pressure drop of 25 mm Hg at rated flow. This device and future iterations of the current design are designed to relieve pulmonary arterial hypertension, provide pulmonary support, reduce ventilator-associated injury, and allow for more effective therapy of patients with end-stage lung disease, including bridge-to-transplant treatment.
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May AG, Orizondo RA, Frankowski BJ, Ye SH, Kocyildirim E, Wagner WR, D'Cunha J, Federspiel WJ. In vivo testing of the low-flow CO 2 removal application of a compact, platform respiratory device. Intensive Care Med Exp 2020; 8:45. [PMID: 32804310 PMCID: PMC7429452 DOI: 10.1186/s40635-020-00329-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 07/16/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Non-invasive and lung-protective ventilation techniques may improve outcomes for patients with an acute exacerbation of chronic obstructive pulmonary disease or moderate acute respiratory distress syndrome by reducing airway pressures. These less invasive techniques can fail due to hypercapnia and require transitioning patients to invasive mechanical ventilation. Extracorporeal CO2 removal devices remove CO2 independent of the lungs thereby controlling the hypercapnia and permitting non-invasive or lung-protective ventilation techniques. We are developing the Modular Extracorporeal Lung Assist System as a platform technology capable of providing three levels of respiratory assist: adult and pediatric full respiratory support and adult low-flow CO2 removal. The objective of this study was to evaluate the in vivo performance of our device to achieve low-flow CO2 removal. METHODS The Modular Extracorporeal Lung Assist System was connected to 6 healthy sheep via a 15.5 Fr dual-lumen catheter placed in the external jugular vein. The animals were recovered and tethered within a pen while supported by the device for 7 days. The pump speed was set to achieve a targeted blood flow of 500 mL/min. The extracorporeal CO2 removal rate was measured daily at a sweep gas independent regime. Hematological parameters were measured pre-operatively and regularly throughout the study. Histopathological samples of the end organs were taken at the end of each study. RESULTS All animals survived the surgery and generally tolerated the device well. One animal required early termination due to a pulmonary embolism. Intra-device thrombus formation occurred in a single animal due to improper anticoagulation. The average CO2 removal rate (normalized to an inlet pCO2 of 45 mmHg) was 75.6 ± 4.7 mL/min and did not significantly change over the course of the study (p > 0.05). No signs of consistent hemolysis or end organ damage were observed. CONCLUSION These in vivo results indicate positive performance of the Modular Extracorporeal Lung Assist System as a low-flow CO2 removal device.
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Affiliation(s)
- Alexandra G May
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
| | - Ryan A Orizondo
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
- Department of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Brian J Frankowski
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
| | - Sang-Ho Ye
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
- Department of Surgery, University of Pittsburgh, Pittsburgh, USA
| | - Ergin Kocyildirim
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
- Department of Cardiothoracic Surgery, Children's Hospital of Pittsburgh, Pittsburgh, USA
| | - William R Wagner
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, USA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA
- Department of Surgery, University of Pittsburgh, Pittsburgh, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA
| | - Jonathan D'Cunha
- Division of Lung Transplantation/Lung Failure, Department of Cardiothoracic Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA
| | - William J Federspiel
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, USA.
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA, 15203, USA.
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, USA.
- Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, USA.
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, USA.
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Abstract
Respiratory failure is a significant problem within the pediatric population. A means of respiratory support that readily allows ambulation could improve treatment. The Pittsburgh Pediatric Ambulatory Lung (P-PAL) is being developed as a wearable pediatric pump-lung for long-term respiratory support and has previously demonstrated positive benchtop results. This study aimed to evaluate acute (4-6 hours) in vivo P-PAL performance, as well as develop an optimal implant strategy for future long-term studies. The P-PAL was connected to healthy sheep (n = 6, 23-32 kg) via cannulation of the right atrium and pulmonary artery. Plasma-free hemoglobin (PfHb) and animal hemodynamics were measured throughout the study. Oxygen transfer rates were measured at blood flows of 1-2.5 L/min. All animals survived the complete study duration with no device exchanges. Flow limitation because of venous cannula occlusion occurred in trial 2 and was remedied via an altered cannulation approach. Blood exiting the P-PAL had 100% oxygen saturation with the exception of trial 4 during which inadequate device priming led to intrabundle clot formation. Plasma-free hemoglobin remained low (<20 mg/dl) for all trials. In conclusion, this study demonstrated successful performance of the P-PAL in an acute setting and established the necessary methods for future long-term evaluation.
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Sarode DN, Roy S. In Vitro models for thrombogenicity testing of blood-recirculating medical devices. Expert Rev Med Devices 2019; 16:603-616. [PMID: 31154869 DOI: 10.1080/17434440.2019.1627199] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Blood-recirculating medical devices, such as mechanical circulatory support (MCS), extracorporeal membrane oxygenators (ECMO), and hemodialyzers, are commonly used to treat or improve quality of life in patients with cardiac, pulmonary, and renal failure, respectively. As part of their regulatory approval, guidelines for thrombosis evaluation in pre-clinical development have been established. In vitro testing evaluates a device's potential to produce thrombosis markers in static and dynamic flow loops. AREAS COVERED This review focuses on in vitro static and dynamic models to assess thrombosis in blood-recirculating medical devices. A summary of key devices is followed by a review of molecular markers of contact activation. Current thrombosis testing guidance documents, ISO 10993-4, ASTM F-2888, and F-2382 will be discussed, followed by analysis of their application to in vitro testing models. EXPERT OPINION In general, researchers have favored in vivo models to thoroughly evaluate thrombosis, limiting in vitro evaluation to hemolysis. In vitro studies are not standardized and it is often difficult to compare studies on similar devices. As blood-recirculating devices have advanced to include wearable and implantable artificial organs, expanded guidelines standardizing in vitro testing are needed to identify the thrombotic potential without excessive use of in vivo resources during pre-clinical development.
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Affiliation(s)
- Deepika N Sarode
- a Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , CA , USA
| | - Shuvo Roy
- a Department of Bioengineering and Therapeutic Sciences , University of California , San Francisco , CA , USA
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Karimov JH, Horvath DJ, Byram N, Sunagawa G, Kuban BD, Gao S, Dessoffy R, Fukamachi K. Early in vivo experience with the pediatric continuous-flow total artificial heart. J Heart Lung Transplant 2018; 37:1029-1034. [PMID: 29703578 PMCID: PMC6647019 DOI: 10.1016/j.healun.2018.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/14/2018] [Accepted: 03/28/2018] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Heart transplantation in infants and children is an accepted therapy for end-stage heart failure, but donor organ availability is low and always uncertain. Mechanical circulatory support is another standard option, but there is a lack of intracorporeal devices due to size and functional range. The purpose of this study was to evaluate the in vivo performance of our initial prototype of a pediatric continuous-flow total artificial heart (P-CFTAH), comprising a dual pump with one motor and one rotating assembly, supported by a hydrodynamic bearing. METHODS In acute studies, the P-CFTAH was implanted in 4 lambs (average weight: 28.7 ± 2.3 kg) via a median sternotomy under cardiopulmonary bypass. Pulmonary and systemic pump performance parameters were recorded. RESULTS The experiments showed good anatomical fit and easy implantation, with an average aortic cross-clamp time of 98 ± 18 minutes. Baseline hemodynamics were stable in all 4 animals (pump speed: 3.4 ± 0.2 krpm; pump flow: 2.1 ± 0.9 liters/min; power: 3.0 ± 0.8 W; arterial pressure: 68 ± 10 mm Hg; left and right atrial pressures: 6 ± 1 mm Hg, for both). Any differences between left and right atrial pressures were maintained within the intended limit of ±5 mm Hg over a wide range of ratios of systemic-to-pulmonary vascular resistance (0.7 to 12), with and without pump-speed modulation. Pump-speed modulation was successfully performed to create arterial pulsation. CONCLUSION This initial P-CFTAH prototype met the proposed requirements for self-regulation, performance, and pulse modulation.
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Affiliation(s)
- Jamshid H Karimov
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Nicole Byram
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Gengo Sunagawa
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Barry D Kuban
- Medical Device Solutions, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Shengqiang Gao
- Medical Device Solutions, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Raymond Dessoffy
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
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