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Bresette CA, Shea SM, Wagoner S, Bakshi S, Deshpande SR, Maher KO, Ku DN. Novel tubing connectors reduce ECMO circuit thrombosis. Int J Artif Organs 2024; 47:347-355. [PMID: 38742758 DOI: 10.1177/03913988241252255] [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] [Indexed: 05/16/2024]
Abstract
BACKGROUND Thrombosis within extracorporeal membrane oxygenation (ECMO) circuits is a common complication that dominates clinical management of patients receiving mechanical circulatory support. Prior studies have identified that over 80% of circuit thrombosis can be attributed to tubing-connector junctions. METHODS A novel connector was designed that reduces local regions of flow stagnation at the tubing-connector junction to eliminate a primary source of ECMO circuit thrombi. To compare clotting between the novel connectors and the traditional connectors, both in vitro loops and an in vivo caprine model of long-term (48 h) ECMO were used to generate tubing-connector junction clots. RESULTS In vitro, the traditional connectors uniformly (9/9) formed large thrombi, while novel connectors formed a small thrombus in only one of nine (p < 0.0001). In the long-term goat ECMO circuits, the traditional connectors exhibited more thrombi (p < 0.04), and these thrombi were more likely to protrude into the lumen of the tubing (p < 0.001). CONCLUSION Both in vitro and in vivo validation experiments successfully recreated circuit thrombosis and demonstrate that the adoption of novel connectors can reduce the burden of circuit thrombosis.
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Affiliation(s)
| | | | | | - Saagar Bakshi
- Georgia Institute of Technology, Atlanta, GA, USA
- Emory University School of Medicine, Atlanta, GA, USA
| | | | - Kevin O Maher
- Children's Healthcare of Atlanta, Atlanta, GA, USA
- Emory University School of Medicine, Atlanta, GA, USA
| | - David N Ku
- Georgia Institute of Technology, Atlanta, GA, USA
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2
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Berk ZBK, Shah A, Sun W, Griffith BP, Wu ZJ. An ex vivo comparison of partial thromboplastin time and activated clotting time for heparin anticoagulation in an ovine model. Artif Organs 2022; 46:501-505. [PMID: 34698388 PMCID: PMC8882126 DOI: 10.1111/aor.14094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/14/2021] [Accepted: 10/13/2021] [Indexed: 12/26/2022]
Abstract
BACKGROUND Sheep are a primary model of mechanical circulatory support (MCS) with heparin anticoagulation therapy frequently being monitored by activated clotting time (ACT) due to ease and cost. In patients undergoing long-term heparin therapy, other anticoagulation monitoring strategies, such as activated partial thromboplastin time (aPTT), have proven to be more reliable indicators for the adequacy of anticoagulation, frequently determined by heparin concentration. As there is a paucity of similar studies in sheep, we sought to investigate the correlation between heparin concentration and ACT and aPTT using whole sheep blood in an ex vivo model. METHODS Fresh whole blood was serially drawn from an adult female Dorset-hybrid sheep and aliquots were placed into tubes containing heparin saline solutions with concentrations ranging from 0 to 7.81 U heparin per mL of whole blood. ACT and aPTT values were measured on each of the samples. The experiment was performed four times with the same animal. A simple linear regression was performed to determine correlation, and subgroup analysis was performed on low versus high heparin concentrations typically seen in human patients on long-term MCS, such as extracorporeal membrane oxygenation (ECMO), versus cardiopulmonary bypass, respectively. RESULTS aPTT measurements versus the heparin concentration had an R2 = 0.7295. ACT measurements versus the heparin concentration had a R2 = 0.4628. aPTT measurements versus the ACT measurements had a R2 = 0.2974. The strength of the correlation between aPTT and heparin concentration increased at low heparin concentrations (R2 = 0.8392). CONCLUSION aPTT had a more reliable correlation to heparin concentration and thus anticoagulation level than ACT. This was particularly true at lower heparin concentrations, similar to ranges seen for patients on ECMO. The correlation between aPTT and ACT values was poor. Further in vivo studies should be performed to confirm our results.
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Affiliation(s)
- Zachary B. K. Berk
- Department of Surgery Division of Cardiac Surgery University of Maryland School of Medicine Baltimore Maryland USA
| | - Aakash Shah
- Department of Surgery Division of Cardiac Surgery University of Maryland School of Medicine Baltimore Maryland USA
| | - Wenji Sun
- Department of Surgery Division of Cardiac Surgery University of Maryland School of Medicine Baltimore Maryland USA
| | - Bartley P. Griffith
- Department of Surgery Division of Cardiac Surgery University of Maryland School of Medicine Baltimore Maryland USA
| | - Zhongjun J. Wu
- Department of Surgery Division of Cardiac Surgery University of Maryland School of Medicine Baltimore Maryland USA
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3
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Mariani S, Li T, Hegermann J, Bounader K, Hanke J, Meyer T, Jannsen-Peters H, Haverich A, Schmitto JD, Dogan G. Biocompatibility of an apical ring plug for left ventricular assist device explantation: Results of a feasibility pre-clinical study. Artif Organs 2021; 46:827-837. [PMID: 34904254 DOI: 10.1111/aor.14149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 09/29/2021] [Accepted: 12/08/2021] [Indexed: 12/25/2022]
Abstract
BACKGROUND Patients receiving left ventricle assist devices (LVADs) as bridge to recovery remain a minority with 1%-5% of LVADs explanted after improvement of myocardial function. Nevertheless, considering the growing population of patients supported with LVADs, an increasing demand of new explantation strategies is expected in the near future. A novel plug for LVAD explantation has been developed and its biocompatibility profile needs to be proved. This study tested the biocompatibility of this novel plug in an in vivo ovine model. METHODS Six adult Blackhead Persian female sheep received plug implantation on the cardiac apex via minimally invasive approach and were clinically observed up to 90 days. Echocardiography was performed to detect thrombus formation or further plug-related complications. After the observation period, euthanasia was performed and samples including the plug and the surrounding tissues were obtained to be analyzed with correlative light and electron microscopy. Organ necrosis, ischemia and peripheral embolism were investigated. RESULTS Three animals survived surgery and completed the follow-up time without experiencing clinical complications. Echocardiographic controls excluded the presence of an intracavitary thrombus in the left ventricle (LV). Autopsy confirmed no signs of local infection, LV thrombus or peripheral embolism. Light and electron microscopy revealed an intact epithelium covering a layer of connective tissue on the plug surface facing the heart lumen. CONCLUSIONS This novel apical plug for LVAD explantation allows for endothelial and connective tissue growth on its ventricular side within 90 days from surgery. Further studies are required to fully demonstrate the biocompatibility of this apical plug and investigate the optimal anticoagulation regimen to be applied after implantation.
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Affiliation(s)
- Silvia Mariani
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany.,Cardio-Thoracic Surgery Department, Maastricht University Medical Centre (MUMC+), Maastricht, The Netherlands
| | - Tong Li
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Karl Bounader
- Division of Cardiothoracic and Vascular Surgery, Pontchaillou University Hospital, Rennes, France
| | - Jasmin Hanke
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | | | | | - Axel Haverich
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Jan D Schmitto
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Günes Dogan
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
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4
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Cysyk JP, Lukic B, Joseph Brian C, Newswanger R, Jhun CS, Izer J, Flory H, Reibson J, Doxtater B, Weiss W, Rosenberg G. Miniaturized Fontan Circulation Assist Device: Chronic In Vivo Evaluation. ASAIO J 2021; 67:1240-1249. [PMID: 33883510 DOI: 10.1097/mat.0000000000001439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We have miniaturized and optimized our implantable rotary blood pump developed to provide long-term mechanical right heart support for patients who have failing Fontan circulation. The objective of this study was to evaluate the miniaturized Fontan circulation assist device (mini-FCAD) during 30-day sheep studies (n = 5). A complete right heart bypass was performed and all return flow was supported by the pump. Postoperatively, unfractionated heparin was given to maintain thromboelastography R times of 2× normal. The first two studies were terminated on day 0 and day 4 due to complications. In the final three studies, the animals remained healthy and were electively terminated at 30 ± 2 days. Pump flow was between 5 and 7 lpm, left atrial pressure remained normal, and inlet pressures were between 3 and 18 mm Hg with no incidents of suction. There was no evidence of hemolysis, end organ or pulmonary dysfunction, thromboembolic events, nor thermal damage to the surrounding tissue. Explanted devices from two studies were free of thrombi and in the third study there were unattached thrombi on the SVC inlet of the rotor. The mini-FCAD was successfully tested in vivo as a right heart replacement device demonstrating adequate circulatory support and normal physiologic pulmonary and venous pressures.
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Affiliation(s)
- Joshua P Cysyk
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Branka Lukic
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Clark Joseph Brian
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
- Department of Pediatrics, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Ray Newswanger
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Choon-Sik Jhun
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Jenelle Izer
- Department of Comparative Medicine, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Heidi Flory
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - John Reibson
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Bradley Doxtater
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - William Weiss
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Gerson Rosenberg
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
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5
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Butty EM, McKinney CA, Prisk AJ. Treatment of a flunixin meglumine overdose with intravenous administration of lipid emulsion and therapeutic plasma exchange in a Nigerian dwarf buck kid (Capra aegagrus hircus). J Vet Intern Med 2021; 35:1626-1630. [PMID: 33934401 PMCID: PMC8163127 DOI: 10.1111/jvim.16124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 12/30/2022] Open
Abstract
A 12 week‐old Nigerian dwarf (Capra aegagrus hircus) buck kid was hospitalized for management of obstructive urolithiasis. Postoperatively, he was inadvertently administered 16‐times greater than his calculated dose of a nonsteroidal anti‐inflammatory drug (NSAID; 17.5 mg/kg flunixin meglumine, IV). The goat was treated with intravenous administration of lipid emulsion (ILE) prior to membrane‐based therapeutic plasma exchange (mTPE) under general anesthesia. The increased coagulability inherent to small ruminants in comparison with dogs and cats warranted specific adjustments in the prescription of anticoagulation, blood flow, and filtration fraction to avoid circuit clotting during mTPE. Serum flunixin meglumine concentration measured before, during, and after mTPE revealed marked reduction in drug concentration. After the combined treatments, no clinical evidence of NSAID gastrointestinal or renal toxicosis was detected. This case report describes successful management of flunixin meglumine overdose in a small ruminant using combined ILE and mTPE.
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Affiliation(s)
- Emmanuelle Marie Butty
- Department of Clinical Sciences, Small Animal Internal Medicine, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Caroline Ann McKinney
- Department of Clinical Sciences, Large Animal Internal Medicine, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
| | - Amanda Jane Prisk
- Department of Clinical Sciences, Large Animal Surgery, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts, USA
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Fang S, Ellman DG, Andersen DC. Review: Tissue Engineering of Small-Diameter Vascular Grafts and Their In Vivo Evaluation in Large Animals and Humans. Cells 2021; 10:713. [PMID: 33807009 PMCID: PMC8005053 DOI: 10.3390/cells10030713] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/10/2021] [Accepted: 03/15/2021] [Indexed: 12/15/2022] Open
Abstract
To date, a wide range of materials, from synthetic to natural or a mixture of these, has been explored, modified, and examined as small-diameter tissue-engineered vascular grafts (SD-TEVGs) for tissue regeneration either in vitro or in vivo. However, very limited success has been achieved due to mechanical failure, thrombogenicity or intimal hyperplasia, and improvements of the SD-TEVG design are thus required. Here, in vivo studies investigating novel and relative long (10 times of the inner diameter) SD-TEVGs in large animal models and humans are identified and discussed, with emphasis on graft outcome based on model- and graft-related conditions. Only a few types of synthetic polymer-based SD-TEVGs have been evaluated in large-animal models and reflect limited success. However, some polymers, such as polycaprolactone (PCL), show favorable biocompatibility and potential to be further modified and improved in the form of hybrid grafts. Natural polymer- and cell-secreted extracellular matrix (ECM)-based SD-TEVGs tested in large animals still fail due to a weak strength or thrombogenicity. Similarly, native ECM-based SD-TEVGs and in-vitro-developed hybrid SD-TEVGs that contain xenogeneic molecules or matrix seem related to a harmful graft outcome. In contrast, allogeneic native ECM-based SD-TEVGs, in-vitro-developed hybrid SD-TEVGs with allogeneic banked human cells or isolated autologous stem cells, and in-body tissue architecture (IBTA)-based SD-TEVGs seem to be promising for the future, since they are suitable in dimension, mechanical strength, biocompatibility, and availability.
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Affiliation(s)
- Shu Fang
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- The Danish Regenerative Center, Odense University Hospital, J. B. Winsløwsvej 4, 5000 Odense C, Denmark
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
| | - Ditte Gry Ellman
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
| | - Ditte Caroline Andersen
- Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital, J. B. Winsløwsvej 25, 5000 Odense C, Denmark; (D.G.E.); (D.C.A.)
- The Danish Regenerative Center, Odense University Hospital, J. B. Winsløwsvej 4, 5000 Odense C, Denmark
- Institute of Clinical Research, University of Southern Denmark, J. B. Winsløwsvej 19, 5000 Odense C, Denmark
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7
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De Potter T, Yodfat O, Shinar G, Neta A, Reddy VY, Neuzil P, Veltkamp R, Connolly SJ. Permanent Bilateral Carotid Filters for Stroke Prevention in Atrial Fibrillation. Curr Cardiol Rep 2020; 22:144. [PMID: 32910288 PMCID: PMC7496024 DOI: 10.1007/s11886-020-01388-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Purpose of Review A novel permanent carotid filter device for percutaneous implantation was developed for the purpose of stroke prevention. In this review, we cover rationale, existing preclinical and clinical data, and potential future directions for research using such a device. Recent Findings The Vine™ filter was assessed for safety in sheep and in 2 observational human studies, the completed CAPTURE 1 (n = 25) and the ongoing CAPTURE 2 (planned n = 100). CAPTURE 1 has shown high procedural and long-term implant safety. A control group was not available for comparison. Summary A mechanical filter for permanent stroke prevention can be implanted bilaterally in the common carotid artery safely and efficiently. A randomized trial is planned for 2021 (n = 3500, INTERCEPT) to demonstrate superiority of a filter + anticoagulation strategy over anticoagulation alone in patients at high risk for ischemic stroke.
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Affiliation(s)
- Tom De Potter
- Cardiovascular Center, OLV Hospital, Moorselbaan 164, B-9300 Aalst, Belgium
| | | | | | | | - Vivek Y. Reddy
- Helmsley Electrophysiology Center, Division of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - Petr Neuzil
- Department of Cardiology, Homolka Hospital, Prague, Czech Republic
| | - Roland Veltkamp
- Department of Brain Science, Imperial College London, London, UK
- Department of Neurology, Alfried Krupp Krankenhaus, Essen, Germany
- Department of Neurology, University Heidelberg, Heidelberg, Germany
| | - Stuart J. Connolly
- Population Health Research Institute, McMaster University, Hamilton, Ontario Canada
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8
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A Permanent Common Carotid Filter for Stroke Prevention in Atrial Fibrillation: Ex Vivo and In Vivo Pre-Clinical Testing. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2020; 21:1587-1593. [PMID: 32522397 DOI: 10.1016/j.carrev.2020.05.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE A novel, permanent, bilateral, common carotid artery (CCA) coil filter implant was designed to capture stroke-producing emboli in atrial fibrillation patients. Under ultrasound guidance, it is automatically deployed through a 24-guage needle and is retrievable up to 4 h post-procedure. We assessed the feasibility, safety, and effectiveness of the CCA filter in pre-clinical testing. METHODS In a pulsatile flow simulator, the filter's embolic capture efficiency and integrity of simulated (1.2 mm diameter nylon balls) and actual thromboemboli were tested. Implant insertion, retrieval, and chronic safety were tested in sheep by ultrasound and X-ray. At termination, the CCAs were explanted and examined by pathology, histopathology and scanning electron microscopy. The fate of captured emboli was evaluated in sheep 3 weeks after upstream injection of autologous thromboemboli. RESULTS In the flow simulator, 10 filters captured 29 of 29 (100%) 1.2 mm diameter nylon balls. In the thromboemboli integrity test, all captured thromboemboli (99 of 99) were adherent to the filter, without fragmentation. All sheep (n = 30/60 implants) underwent successful CCA filter implantation. During follow-ups at 4, 12, 13, 23, and 31 weeks (6 sheep/12 implants at each follow-up), there were no (0%) major bleeds, CCA damage/stenosis, implant migration, flow obstruction, or thrombi detected by ultrasound. Two organized microthrombi (<100 μm) were observed by histopathology at the puncture site. After 3 weeks, autologous captured thromboemboli (n = 10) either completely regressed (5 of 5) or did not progress (5 of 5). CONCLUSION These favorable pre-clinical results prompt clinical testing of the CCA filter in stroke prevention clinical trials.
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9
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Lukic B, Clark JB, Izer JM, Cooper TK, Finicle HA, Cysyk J, Doxtater B, Yeager E, Reibson J, Newswanger RK, Leibich P, Bletcher K, Weiss WJ. Chronic Ovine Studies Demonstrate Low Thromboembolic Risk in the Penn State Infant Ventricular Assist Device. ASAIO J 2020; 65:371-379. [PMID: 30681440 DOI: 10.1097/mat.0000000000000945] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Mechanical circulatory support for children under 6 years of age remains a challenge. This article describes the preclinical status and the results of recent animal testing with the Penn State Infant Left Ventricular Assist Device (VAD). The objectives have been to 1) demonstrate acceptably low thromboembolic risk to support Food and Drug Administration approval, 2) challenge the device by using minimal to no anticoagulation in order to identify any design or manufacturing weaknesses, and 3) improve our understanding of device thrombogenicity in the ovine animal model, using multicomponent measurements of the coagulation system and renal ischemia quantification, in order to better correlate animal results with human results.The Infant VAD was implanted as a left VAD (LVAD) in 18-29 kg lambs. Twelve LVAD and five surgical sham animals were electively terminated after approximately 30 or 60 days. Anticoagulation was by unfractionated heparin targeting thromboelastography R times of 2x normal (n = 6) or 1x normal (n = 6) resulting in negligible heparin activity as measured by anti-Xa assay (<0.1 IU/ml). Platelet inhibitors were not used.There were no clinically evident strokes or evidence of end organ dysfunction in any of the 12 electively terminated LVAD studies. The degree of renal ischemic lesions in device animals was not significantly different than that found in five surgical sham studies, demonstrating minimal device thromboembolism.In summary, these results in a challenging animal test protocol support the conclusion that the Penn State Infant VAD has a low thromboembolic risk and may allow lower levels of anticoagulation.
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Affiliation(s)
- Branka Lukic
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - J Brian Clark
- Pediatric Cardiothoracic Surgery, The Pennsylvania State University, College of Medicine, Penn State Children's Hospital, Hershey, PA
| | - Jenelle M Izer
- Department of Comparative Medicine, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Timothy K Cooper
- Department of Comparative Medicine, The Pennsylvania State University, College of Medicine, Hershey, PA.,Present address: Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, Maryland
| | - Heidi A Finicle
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Johua Cysyk
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Bradly Doxtater
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Eric Yeager
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - John Reibson
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Raymond K Newswanger
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Patrick Leibich
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - Kirby Bletcher
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA
| | - William J Weiss
- From the Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, PA.,Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA
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10
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Jalaie H, Steitz J, Afify M, Barbati ME, Hoeft K, Assar MAM, Hermanns-Sachweh B, Tolba RH, Jacobs MJ, Schleimer K. In vivo endothelialization and neointimal hyperplasia assessment after angioplasty of sheep carotid artery with a novel polycarbonate polyurethane patch. J Biomater Appl 2019; 34:208-218. [PMID: 31088184 DOI: 10.1177/0885328219849368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Houman Jalaie
- 1 European Vascular Center Aachen-Maastricht, Department of Vascular Surgery, University Hospital RWTH Aachen, Germany
| | - Julia Steitz
- 2 Institute for Laboratory Animal Science, RWTH-Aachen University, Germany
| | - Mamdouh Afify
- 2 Institute for Laboratory Animal Science, RWTH-Aachen University, Germany.,3 Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Egypt
| | - Mohammad Esmaeil Barbati
- 1 European Vascular Center Aachen-Maastricht, Department of Vascular Surgery, University Hospital RWTH Aachen, Germany
| | - Konrad Hoeft
- 4 Division of Nephrology and Clinical Immunology, University Hospital RWTH Aachen, Germany
| | - Mona Ali Mahmoud Assar
- 2 Institute for Laboratory Animal Science, RWTH-Aachen University, Germany.,6 Institute for Pathology, RWTH-Aachen University, Germany
| | | | - Rene H Tolba
- 2 Institute for Laboratory Animal Science, RWTH-Aachen University, Germany
| | - Michael J Jacobs
- 1 European Vascular Center Aachen-Maastricht, Department of Vascular Surgery, University Hospital RWTH Aachen, Germany
| | - Karina Schleimer
- 1 European Vascular Center Aachen-Maastricht, Department of Vascular Surgery, University Hospital RWTH Aachen, Germany
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Eghbalzadeh K, Guschlbauer M, Weber C, Wacker MT, Reinhardt S, Djordjevic I, Sabashnikov A, Maul A, Sterner-Kock A, Wahlers TCW, Scherner M, Wippermann J. Experimental Studies for Small Diameter Grafts in an In Vivo Sheep Model-Techniques and Pitfalls. Thorac Cardiovasc Surg 2019; 69:649-659. [PMID: 31030422 DOI: 10.1055/s-0039-1687887] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Scientific attempts to create the "ideal" small diameter vascular graft have been compared with the "search of the holy grail." Prosthetic material as expanded polytetrafluoroethylene or Dacron shows acceptable patency rates to large caliber vessels, while small diameter (< 6 mm) prosthetic conduits present unacceptably poor patency rates. Vascular tissue engineering represents a promising option to address this problem. MATERIAL AND METHODS Thirty-two female Texel-sheep aged 6 months to 2 years underwent surgical common carotid artery (CCA) interposition using different tissue-engineered vascular substitutes. Explantation of the grafts was performed 12 (n = 12) and 36 (n = 20) weeks after surgery. Ultrasound was performed on postoperative day 1 and thereafter every 4 weeks to evaluate the graft patency. RESULTS The average length of implanted substitutes was 10.3 ± 2.2 cm. Anesthesia and surgical procedure could be performed without major surgical complications in all cases.The grafts showed a systolic blood flow velocity (BFV) of 28.24 ± 13.5 cm/s, a diastolic BFV of 9.25 ± 4.53 cm/s, and a mean BFV of 17.85 ± 9.25 cm/s. Native vessels did not differ relevantly in hemodynamic measurements (systolic: 29.77 cm/s; diastolic: 7.99 cm/s ± 5.35; mean 15.87 ± 10.75). There was no incidence of neurologic complications or subsequent postoperative occlusion. Perioperative morbidity was low and implantation of conduits was generally well tolerated. CONCLUSION This article aims to give a precise overview of in vivo experiments in sheep for the evaluation of small diameter vascular grafts performing CCA interposition, especially with regard to pitfalls and possible perioperative complications and to discuss advantages and disadvantages of this approach.
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Affiliation(s)
| | - Maria Guschlbauer
- Dezentrales Tierhaltungsnetzwerk, Universitätsklinikum Köln, Cologne, Germany
| | - Carolyn Weber
- Department of Cardiothoracic Surgery, Uniklinik Köln, Köln, Germany
| | - Max Theodor Wacker
- Department of Cardiac Surgery, Universitatsklinikum Magdeburg, Magdeburg, Germany
| | | | - Ilija Djordjevic
- Department of Cardiothoracic Surgery, Uniklinik Köln, Köln, Germany
| | | | - Alexandra Maul
- Department of Experimentelle Medizin, Universitätsklinikum Köln, Cologne, Germany
| | - Anja Sterner-Kock
- Department of Experimentelle Medizin, Universitätsklinikum Köln, Cologne, Germany
| | | | - Maximilian Scherner
- Department of Cardiac Surgery, Universitatsklinikum Magdeburg, Magdeburg, Germany
| | - Jens Wippermann
- Department of Cardiac Surgery, Universitatsklinikum Magdeburg, Magdeburg, Germany
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Johnson CA, Woolley JR, Snyder TA, Shankarraman V, Haney EI, Wagner WR. Assessment of Thrombelastography and Platelet Life Span in Ovines. Artif Organs 2018; 42:E427-E434. [PMID: 30252945 PMCID: PMC6309471 DOI: 10.1111/aor.13282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 04/01/2018] [Indexed: 12/19/2022]
Abstract
Ovines are a common animal model for the study of cardiovascular devices, where consideration of blood biocompatibility is an essential design criterion. In the ovine model, tools to assess blood biocompatibility are limited and continued investigation to identify and apply additional assays is merited. Toward this end, the thrombelastograph, clinically utilized to assess hemostasis, was used to characterize normal ovine parameters. In addition, platelet labeling with biotin was evaluated for its potential applicability to quantify ovine platelet life span. Mean ovine thrombelastograph values were reaction-time: 4.9 min, K-time: 2 min, angle: 64.1°, maximum amplitude: 68.6mm, actual clot strength: 11.9 kd/s, and coagulation index: 1.5. Reaction time was significantly shorter and maximum amplitude, actual clot strength, and coagulation index were all significantly higher when compared to normal human thrombelastograph values suggesting some hypercoagulability of sheep blood. Biotinylation and reinfusion of ovine platelets allowed temporal tracking of the labeled platelet cohort with flow cytometry. These data indicated a mean ovine platelet life span of 188h with a half-life of 84h. The collection of these parameters for normal ovines demonstrates the applicability of these techniques for subsequent studies where cardiovascular devices may be evaluated and provides an indication of normal ovine values for comparison purposes.
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Affiliation(s)
- Carl A. Johnson
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Joshua R. Woolley
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | | | - Venkat Shankarraman
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | | | - William R. Wagner
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA
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13
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Zersen KM, Russell Moore A, Olver CS, Mathis JC. Reference intervals for coagulation variables in healthy adult domestic goats (Capra aegagrus hircus
). Vet Clin Pathol 2018; 47:396-399. [DOI: 10.1111/vcp.12621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kristin M. Zersen
- Department of Microbiology, Immunology and Pathology; Colorado State University; Fort Collins CO USA
| | - A Russell Moore
- Department of Microbiology, Immunology and Pathology; Colorado State University; Fort Collins CO USA
| | - Christine S. Olver
- Department of Microbiology, Immunology and Pathology; Colorado State University; Fort Collins CO USA
| | - Justin C. Mathis
- Department of Microbiology, Immunology and Pathology; Colorado State University; Fort Collins CO USA
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Schleimer K, Jalaie H, Afify M, Woitok A, Barbati ME, Hoeft K, Jacobs M, Tolba RH, Steitz J. Sheep models for evaluation of novel patch and prosthesis material in vascular surgery: tips and tricks to avoid possible pitfalls. Acta Vet Scand 2018; 60:42. [PMID: 29976210 PMCID: PMC6034312 DOI: 10.1186/s13028-018-0397-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 06/27/2018] [Indexed: 11/25/2022] Open
Abstract
Background In vascular surgery, novel synthetic prosthesis materials for patch-angioplasties, interpositions, bypasses and shunts are continuously under development and optimization. The characteristics of an ideal vascular prosthesis would display long-term patency, biocompatibility, durability, low porosity, lack of stich hole bleeding, ease of handling, kink resistance, infection resistance and reasonable costs. The aim of this study was to establish and report a reliable sheep model including potential pitfalls where those parameters could be analyzed. Before surgery, sheep were acclimatized for 4–8 weeks, during which parasite infections were treated and blood and serum parameters monitored. Twenty-four sheep underwent surgery, and carotid patch-angioplasties (n = 12), graft interpositions (n = 6) or arteriovenous prosthetic shunts (n = 6) were implanted. Half of the animals in each group were sacrificed after 2 weeks and the other half after 8 weeks. The implants were analyzed for patency, endothelialization, thrombogenicity and biocompatibility by clinical observation, blood flow measurement and pathological and histopathological (H&E, EvG) as well as immunohistochemical (Ki67, CD31) evaluations. Results Health monitoring of the sheep revealed a parasitic burden with endoparasites in all animals. Some animals showed thereby infestations in the bile duct causing fibrotic cholangitis with calcifications in the liver. In addition, sarcosporidia were detected in histopathological specimen of the heart in all animals. Parasitic burden correlated with blood counts and serum bilirubin levels. Both were significantly reduced by albendazole treatment within the acclimatization time. Patches, interposition grafts, and straight shunts were successfully implanted bilaterally in all animals. The total average operation time was 136 ± 21 min. Most animals (23/24) showed good patency rates and general condition after implantation. Pathological and histopathological/immunohistochemical analyses were suitable to determine thrombogenicity, endothelialization, cellular/fibroblastic proliferation, biocompatibility, inflammatory cell infiltration, and thickness of neointima in the prosthesis material. Conclusions We have developed a suitable experimental protocol with standardized and successful anesthesia- and surgical-procedures for patch-angioplasty, graft interposition, and arteriovenous prosthetic shunts. This sheep model allows testing of new prosthetic materials for biocompatibility, thrombogenicity, and endothelialization.
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15
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Naito N, Takewa Y, Kishimoto S, Iizuka K, Mizuno T, Tsukiya T, Ono M, Tatsumi E. Preclinical animal study of the NIPRO-ventricular assist device for use in pediatric patients. J Artif Organs 2017; 21:156-163. [DOI: 10.1007/s10047-017-1009-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 11/19/2017] [Indexed: 11/24/2022]
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16
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Peppas A, Furer A, Wilson J, Yi G, Cheng Y, Van Wygerden K, Seguin C, Shibuya M, Kaluza GL, Granada JF. Preclinical in vivo long-term evaluation of the novel Mitra-Spacer technology: experimental validation in the ovine model. EUROINTERVENTION 2017; 13:272-279. [PMID: 28262622 DOI: 10.4244/eij-d-16-00609] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIMS The Mitra-Spacer (Cardiosolutions, Bridgewater, MA, USA) is designed to treat mitral regurgitation by introducing a dynamic spacer that constantly adapts to the changing haemodynamic conditions during the cardiac cycle. We aimed to evaluate the performance and safety of this device in the chronic ovine model. METHODS AND RESULTS Eight sheep were enrolled in this study. Through a left thoracotomy, the Mitra-Spacer was inserted via the transapical approach and advanced into the left atrium (LA) under imaging guidance. Device performance and safety were evaluated up to 90 days using fluoroscopy, echocardiography and histopathology. The volume within the balloon spacer shifted during the cardiac cycle in all cases. Seven animals survived up to 90 days for terminal imaging and tissue harvest. Echocardiography showed no change in left ventricle (LV) ejection fraction from baseline to 90 days. There were no observations of changes in LV diastolic function, pulmonary vein inflow, or tricuspid valve function. Histological analysis demonstrated no significant injury to the mitral apparatus. CONCLUSIONS In the healthy ovine model, Mitra-Spacer implantation was feasible and safe. At 90 days, no evidence of structural damage to the mitral apparatus or deterioration of cardiac performance was demonstrated.
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Affiliation(s)
- Athanasios Peppas
- CRF Skirball Center for Innovation, Cardiovascular Research Foundation, Orangeburg, NY, USA
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Alexandre N, Amorim I, Caseiro AR, Pereira T, Alvites R, Rêma A, Gonçalves A, Valadares G, Costa E, Santos-Silva A, Rodrigues M, Lopes MA, Almeida A, Santos JD, Maurício AC, Luís AL. Long term performance evaluation of small-diameter vascular grafts based on polyvinyl alcohol hydrogel and dextran and MSCs-based therapies using the ovine pre-clinical animal model. Int J Pharm 2017; 523:515-530. [PMID: 28283218 DOI: 10.1016/j.ijpharm.2017.02.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The functional and structural performance of a 5cm synthetic small diameter vascular graft (SDVG) produced by the copolymerization of polyvinyl alcohol hydrogel with low molecular weight dextran (PVA/Dx graft) associated to mesenchymal stem cells (MSCs)-based therapies and anticoagulant treatment with heparin, clopidogrel and warfarin was tested using the ovine model during the healing period of 24 weeks. The results were compared to the ones obtained with standard expanded polyetetrafluoroethylene grafts (ePTFE graft). Blood flow, vessel and graft diameter measurements, graft appearance and patency rate (PR), thrombus, stenosis and collateral vessel formation were evaluated by B-mode ultrasound, audio and color flow Doppler. Graft and regenerated vessels morphologic evaluation was performed by scanning electronic microscopy (SEM), histopathological and immunohistochemical analysis. All PVA/Dx grafts could maintain a similar or higher PR and systolic/diastolic laminar blood flow velocities were similar to ePTFE grafts. CD14 (macrophages) and α-actin (smooth muscle) staining presented similar results in PVA/Dx/MSCs and ePTFE graft groups. Fibrosis layer was lower and endothelial cells were only detected at graft-artery transitions where it was added the MSCs. In conclusion, PVA/Dx graft can be an excellent scaffold candidate for vascular reconstruction, including clinic mechanically challenging applications, such as SDVGs, especially when associated to MSCs-based therapies to promote higher endothelialization and lower fibrosis of the vascular prosthesis, but also higher PR values.
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Affiliation(s)
- Nuno Alexandre
- Departamento de Zootecnia, Universidade de Évora, Pólo da Mitra, Apartado 94, 7002-554 Évora, Portugal; Instituto de Ciências Agroambientais Mediterrânicas (ICAAM), Pólo da Mitra, Apartado 94, 7002-554 Évora, Portugal
| | - Irina Amorim
- Departamento de Patologia e de Imunologia Molecular, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal; Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto (UP), Rua Alfredo Allen, 4200-135 Porto, Portugal
| | - Ana Rita Caseiro
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal; Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal; CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - Tiago Pereira
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal; Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Rui Alvites
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal; Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Alexandra Rêma
- Departamento de Patologia e de Imunologia Molecular, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Ana Gonçalves
- Departamento de Patologia e de Imunologia Molecular, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Guilherme Valadares
- Internvet, Rua Academia Recreativa Santo Amaro, n° 13, 1300-001 Lisboa, Portugal
| | - Elísio Costa
- Laboratório de Bioquímica, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto (UP), Rua do Campo Alegre, N°. 823, 4150 Porto, Portugal
| | - Alice Santos-Silva
- Laboratório de Bioquímica, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto (UP), Rua do Campo Alegre, N°. 823, 4150 Porto, Portugal
| | - Miguel Rodrigues
- CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - Maria Ascensão Lopes
- CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - André Almeida
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal
| | - José Domingos Santos
- CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto, Portugal
| | - Ana Colette Maurício
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal; Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Ana Lúcia Luís
- Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências, Tecnologias e Agroambiente da Universidade do Porto (ICETA), Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal; Departamento de Clínicas Veterinárias, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto (UP), Rua de Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal.
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Xu C, Wu G, Liu X, He Y, Hou X, Li H, Chen C, Yang P, Lin C. Preclinical Study of Anticoagulation Regimens in Sheep After Implantation of CH-VAD Blood Pump. Artif Organs 2016; 42:891-898. [PMID: 27925225 DOI: 10.1111/aor.12595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Effective anticoagulation regimens are needed to reduce risks of thrombosis and bleeding in animal models of ventricular assist device to verify its hemocompatibility, biologic safety and reliability. This study is to develop a validated anticoagulation procedure for a sheep model to test the newly developed CH-VAD. CH-VAD models were established in six healthy sheep by constructing blood bypass of left ventricle → ventricular assist device → descending aorta. Heparin infusion was used during operation and in the prior 4 days to maintain activated clotting time 1.5-2.0 times the baseline. From the third day, proper dosage of warfarin was used orally to maintain international normalized ratio values within the range of 1.2-2.0. After termination, we examined whether there was thrombosis in the blood pump, grafts, and anastomotic stoma. Macroscopic and histopathologic examinations were performed in major organs to check for congestion and infarction. Bleeding complications were not found in any animals throughout the experiments. Activated clotting time values were 326 ± 33 s intraoperatively and 157 ± 28 s in the prior 4 days postoperatively. Activated partial thromboplastin time values increased slowly and reached the lower limit of the target range on the fourth day. Only in one of six cases was thrombus or fibrosis tissue found in the blood flow channel of the pump. Pathologic analysis showed no thrombosis, necrosis and microembolus in end-stage organs. Under the anticoagulation regimens, coagulation system could be well controlled to avoid thrombosis and bleeding complications in sheep models for CH-VAD.
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Affiliation(s)
- Chuangye Xu
- Department of Biomedical Engineering, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.,Department of Biomedical Engineering, Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing, China
| | - Guanghui Wu
- Department of Biomedical Engineering, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.,Department of Biomedical Engineering, Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing, China
| | - Xiujian Liu
- Department of Biomedical Engineering, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.,Department of Biomedical Engineering, Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing, China
| | - Yuna He
- Department of Biomedical Engineering, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.,Department of Biomedical Engineering, Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing, China
| | - Xiaotong Hou
- Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Haiyang Li
- Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Chen Chen
- Head Office, ChinaHeart Biomedical Inc., Suzhou, China
| | - Peng Yang
- Head Office, ChinaHeart Biomedical Inc., Suzhou, China
| | - Changyan Lin
- Department of Biomedical Engineering, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.,Department of Biomedical Engineering, Beijing Institute of Heart, Lung, and Blood Vessel Diseases, Beijing, China
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19
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Long term performance evaluation of small-diameter vascular grafts based on polyvinyl alcohol hydrogel and dextran and MSCs-based therapies using the ovine pre-clinical animal model. Int J Pharm 2016; 513:332-346. [DOI: 10.1016/j.ijpharm.2016.09.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 01/04/2023]
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20
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Date K, Kishimoto S, Fujii Y, Togo K, Kakuta Y, Mizuno T, Tsukiya T, Takewa Y, Nishimura T, Ono M, Tatsumi E. Effects of feeding state on anticoagulation in adult goats treated with warfarin. J Artif Organs 2016; 19:301-4. [PMID: 26815203 DOI: 10.1007/s10047-016-0885-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 01/08/2016] [Indexed: 10/22/2022]
Abstract
For the continued development of improved mechanical circulatory systems, longer term evaluation of new devices in animal model experiments may be critical. The effects of anticoagulants in adult goats have not been well studied. We assessed the effects of oral warfarin in three adult goats during fasting or after feeding. The goats [weighing 57.8 ± 8.1 kg (53.0-67.2 kg)] were administered warfarin orally beginning at a dose of 5 mg/day and then increasing to 10, 20, 40, and 60 mg every 2 weeks. One goat (receiving 10 mg/day warfarin) was killed on day 27 because of the inability to stand. After administration of 60 mg warfarin, the remaining goat received no warfarin for 4 days to return to coagulated state. The goats were then fasted and treated with 40 mg warfarin. During warfarin administration, both goats required a dose of 60 mg/day to achieve International Normalized Ratios (INRs) of approximately 2.5; however, when, the animals were in the fasted condition, precipitous extension of INR was observed in 5 days. After resuming feeding, the INR was reduced to the proper range. We showed the tendency that warfarin therapy in goats required higher doses than the doses administered to human patients and that the effects of therapy were related to the feeding state. The results of this study provide important information for development of anticoagulation protocols to assess mechanical circulatory support devices for long-term use in preclinical examination.
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Affiliation(s)
- Kazuma Date
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan. .,Department of Cardiothoracic Surgery, The University of Tokyo, Tokyo, Japan.
| | - Satoru Kishimoto
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
| | - Yutaka Fujii
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Konomi Togo
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Yukihide Kakuta
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Toshihide Mizuno
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Tomonori Tsukiya
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Yoshiaki Takewa
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Takashi Nishimura
- Department of Cardiac Surgery, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
| | - Minoru Ono
- Department of Cardiothoracic Surgery, The University of Tokyo, Tokyo, Japan
| | - Eisuke Tatsumi
- Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan
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DiVincenti L, Westcott R, Lee C. Sheep (Ovis aries) as a model for cardiovascular surgery and management before, during, and after cardiopulmonary bypass. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2015; 35:131-2. [PMID: 25255065 DOI: 10.1002/clc.21952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 11/22/2011] [Indexed: 12/20/2022]
Abstract
Because of its similarity to humans in important respects, sheep (Ovis aries) are a common animal model for translational research in cardiovascular surgery. However, some unique aspects of sheep anatomy and physiology present challenges to its use in these complicated experiments. In this review, we discuss relevant anatomy and physiology of sheep and discuss management before, during, and after procedures requiring cardiopulmonary bypass to provide a concise source of information for veterinarians, technicians, and researchers developing and implementing protocols with this model.
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Affiliation(s)
- Louis DiVincenti
- Department of Comparative Medicine, University of Rochester Medical Center, Rochester, New York, USA.
| | - Robin Westcott
- Division of Laboratory Animal Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Candice Lee
- Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA
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22
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Alexandre N, Costa E, Coimbra S, Silva A, Lopes A, Rodrigues M, Santos M, Maurício AC, Santos JD, Luís AL. In vitro and in vivo evaluation of blood coagulation activation of polyvinyl alcohol hydrogel plus dextran-based vascular grafts. J Biomed Mater Res A 2014; 103:1366-79. [PMID: 25044790 DOI: 10.1002/jbm.a.35275] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 06/11/2014] [Accepted: 07/03/2014] [Indexed: 11/08/2022]
Abstract
Polyvinyl alcohol hydrogel (PVA) is a water-soluble synthetic polymer that is commonly used in biomedical applications including vascular grafting. It was argued that the copolymerization of PVA with dextran (Dx) can result in improvement of blood-biomaterial interactions. The focus of this experimental study was to assess that interaction through an in vivo and in vitro evaluation of the coagulation system activation. The thrombogenicity of the copolymer was determined by quantification of platelet adhesion through the lactate dehydrogenase assay, determination of whole blood clotting time, and by quantification of platelet activation by flow cytometry. The thrombin-antithrombin complex blood levels were also determined. The obtained results for the in vitro assays suggested a non-thrombogenic profile for PVA/Dx. Additionally in vivo coagulation and hematological parameters were determined in an animal model after PVA/Dx vascular graft implantation. For coagulation homeostasis assessment, the intrinsic and extrinsic pathway's activation was determined by measuring prothrombin time (PT) and activated partial thromboplastin time (aPTT). Other markers of coagulation and inflammation activation including d-dimers, interleukin-6, and C-reactive protein were also assessed. The PVA/Dx copolymer tended to inhibit platelet adhesion/activation process and the contact activation process for coagulation. These results were also confirmed with the in vivo experiments where the measurements for APTT, interleukin-6, and C-reactive protein parameters were normal considering the species normal range of values. The response to those events is an indicator of the in vitro and in vivo hemocompatibility of PVA/Dx and it allows us to select this biomaterial for further preclinical trials in vascular reconstruction.
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Affiliation(s)
- Nuno Alexandre
- Departamento de Zootecnia, Universidade de Évora, Pólo da Mitra, Apartado 94, 7002-554, Évora, Portugal; Instituto de Ciências Agro-ambientais Mediterrânicas (ICAAM), Pólo da Mitra, Apartado 94, 7002-554, Évora, Portugal
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23
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Weigand A, Boos AM, Ringwald J, Mieth M, Kneser U, Arkudas A, Bleiziffer O, Klumpp D, Horch RE, Beier JP. New aspects on efficient anticoagulation and antiplatelet strategies in sheep. BMC Vet Res 2013; 9:192. [PMID: 24088206 PMCID: PMC3851128 DOI: 10.1186/1746-6148-9-192] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 09/26/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND After addressing fundamental questions in preclinical models in vitro or in small animals in vivo, the translation into large animal models has become a prerequisite before transferring new findings to human medicine. Especially in cardiovascular, orthopaedic and reconstructive surgery, the sheep is an important in vivo model for testing innovative therapies or medical devices prior to clinical application. For a wide variety of sheep model based research projects, an optimal anticoagulation and antiplatelet therapy is mandatory. However, no standardised scheme for this model has been developed so far. Thus the efficacy of antiplatelet (acetylsalicylic acid, clopidogrel, ticagrelor) and anticoagulant (sodium enoxaparin, dabigatran etexilate) strategies was evaluated through aggregometry, anti-factor Xa activity and plasma thrombin inhibitor levels in sheep of different ages. RESULTS Responses to antiplatelet and anticoagulant drugs in different concentrations were studied in the sheep. First, a baseline for the measurement of platelet aggregation was assessed in 20 sheep. The effectiveness of 225 mg clopidogrel twice daily (bid) in 2/5 sheep and 150 mg bid in 3/5 lambs could be demonstrated, while clopidogrel and its metabolite carboxylic acid were detected in every plasma sample. High dose ticagrelor (375 mg bid) resulted in sufficient inhibition of platelet aggregation in 1/5 sheep, while acetylsalicylic acid did not show any antiplatelet effect. Therapeutic anti-factor Xa levels were achieved with age-dependent dosages of sodium enoxaparin (sheep 3 mg/kg bid, lambs 5 mg/kg bid). Administration of dabigatran etexilate resulted in plasma concentrations similar to human ranges in 2/5 sheep, despite receiving quadruple dosages (600 mg bid). CONCLUSION High dosages of clopidogrel inhibited platelet aggregation merely in a low number of sheep despite sufficient absorption. Ticagrelor and acetylsalicylic acid cannot be recommended for platelet inhibition in sheep. Efficient anticoagulation can be ensured using sodium enoxaparin rather than dabigatran etexilate in age-dependent dosages. The findings of this study significantly contribute to the improvement of a safe and reliable prophylaxis for thromboembolic events in sheep. Applying these results in future translational experimental studies may help to avoid early dropouts due to thromboembolic events and associated unnecessary high animal numbers.
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Affiliation(s)
- Annika Weigand
- Department of Plastic and Hand Surgery, University Hospital of Erlangen Friedrich-Alexander University of Erlangen-Nürnberg, Krankenhausstr, 12, Erlangen D-91054, Germany.
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Siller-Matula JM, Miller I, Gemeiner M, Plasenzotti R, Bayer G, Mesteri I, Fabry A, Petroczi K, Nöbauer K, Razzazi-Fazeli E, Planchon S, Renaut J, Quehenberger P, Selzer E, Jilma B. Continuous thrombin infusion leads to a bleeding phenotype in sheep. Thromb Res 2012; 130:226-36. [DOI: 10.1016/j.thromres.2011.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 11/30/2022]
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Jian Y, Tian X, Li Q, Li B, Peng Z. Comparison of methods for staining microvessels in bone. Biotech Histochem 2012; 87:428-31. [PMID: 22762211 DOI: 10.3109/10520295.2012.696701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Detection of microvessels is critical for studying bone tissue. We developed an intravascular ink-based method coupled with Van Gieson (VG) staining and compared it with other commonly used methods for capillary visualization. The ink perfusate was formulated as 10% ink, 10% formaldehyde and 20% mannitol. The ink solution was perfused into a healthy goat and the tibia was subjected to decalcification, dehydration, paraffin embedding, de-waxing and staining to observe microvessels. Angiogenesis was assessed by vascular area image analysis and the hematoxylin and eosin (HE), Masson, and VG staining techniques were compared to determine the reliability of these methods for counting microvessels. We found that HE, Masson, and VG staining produced poor contrast between the microvessels and surrounding tissues. By contrast, ink coupled with VG staining permitted clear discrimination between the microvessels and surrounding tissues. Our results indicate that ink-VG staining could be more useful than other methods for detecting tissue microvessels.
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Affiliation(s)
- Yuekui Jian
- Department of Orthopaedics, Guizhou Provincial People's Hospital, Guiyang, China
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Sasaki T, Tsuda S, Trujillo M, Kirk Riemer R, Reinhartz O. Maintenance dose of warfarin in sheep and effect of diet: a preliminary report. J INVEST SURG 2012; 25:29-32. [PMID: 22272634 DOI: 10.3109/08941939.2011.598219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sheep models are widely used to evaluate the feasibility of various cardiac assist devices. Anticoagulation therapy postoperatively, however, is seldomly reported on. Continuous heparin infusion is often used, but is cumbersome due to long-term line management with the risk of infection and dislodgement. We contemplated using warfarin instead and started a pilot dose-finding study. Three sheep were given oral warfarin between 0.1 and 0.3 mg/kg/day. Prothrombin time was monitored and INR was calculated daily. If the INR did not reach a target of 2.5-3.5, warfarin dose was doubled. We found that sheep required a dose of warfarin between 1.6 and 2.4 mg/kg/day to raise the INR to the target zone. In a subsequent study to evaluate the effect of diet on INR in sheep, three sheep were fed alfalfa hay or alfalfa pellets in a crossover design. All the animals were given warfarin at the dose of 1.6 mg/kg. The diet was switched when the INR reached the target zone of 2.5-3.5. Hay-fed animals reached the target INR on days 6 and 7. On the other hand, pellet-fed animals did not reach the target value by day 7 with the initial dose and required 2.4 mg/kg of warfarin to achieve the goal. Hay raised the INR faster and higher than pellets with the same warfarin dose. Hay may be advantageous when using oral warfarin therapy in sheep.
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Affiliation(s)
- Takashi Sasaki
- Division of Pediatric Cardiac Surgery, Department of Cardiothoracic Surgery, Stanford University, Stanford, California, USA.
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Peng H, Schlaich EM, Row S, Andreadis ST, Swartz DD. A novel ovine ex vivo arteriovenous shunt model to test vascular implantability. Cells Tissues Organs 2011; 195:108-21. [PMID: 22005667 DOI: 10.1159/000331415] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The major objective of successful development of tissue-engineered vascular grafts is long-term in vivo patency. Optimization of matrix, cell source, surface modifications, and physical preconditioning are all elements of attaining a compatible, durable, and functional vascular construct. In vitro model systems are inadequate to test elements of thrombogenicity and vascular dynamic functional properties while in vivo implantation is complicated, labor-intensive, and cost-ineffective. We proposed an ex vivo ovine arteriovenous shunt model in which we can test the patency and physical properties of vascular grafts under physiologic conditions. The pressure, flow rate, and vascular diameter were monitored in real-time in order to evaluate the pulse wave velocity, augmentation index, and dynamic elastic modulus, all indicators of graft stiffness. Carotid arteries, jugular veins, and small intestinal submucosa-based grafts were tested. SIS grafts demonstrated physical properties between those of carotid arteries and jugular veins. Anticoagulation properties of grafts were assessed via scanning electron microscopy imaging, en face immunostaining, and histology. Luminal seeding with endothelial cells greatly decreased the attachment of thrombotic components. This model is also suture free, allowing for multiple samples to be stably processed within one animal. This tunable (pressure, flow, shear) ex vivo shunt model can be used to optimize the implantability and long-term patency of tissue-engineered vascular constructs.
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Affiliation(s)
- Haofan Peng
- Department of Chemical and Biological Engineering, Women and Children's Hospital of Buffalo, N.Y., USA
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Gauthier T, Bertin F, Fourcade L, Maubon A, Saint Marcoux F, Piver P, Marquet P, Pommepuy I, Plainard X, Couquet C, Cornuejols MJ, Essig M, Aubard Y. Uterine allotransplantation in ewes using an aortocava patch. Hum Reprod 2011; 26:3028-36. [DOI: 10.1093/humrep/der288] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Byrom MJ, Bannon PG, White GH, Ng MKC. Animal models for the assessment of novel vascular conduits. J Vasc Surg 2010; 52:176-95. [PMID: 20299181 DOI: 10.1016/j.jvs.2009.10.080] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/25/2009] [Accepted: 10/04/2010] [Indexed: 11/19/2022]
Abstract
The development of an ideal small-diameter conduit for use in vascular bypass surgery has yet to be achieved. The ongoing innovation in biomaterial design generates novel conduits that require preclinical assessment in vivo, and a number of animal models have been used for this purpose. This article examines the rationale behind animal models used in the assessment of small-diameter vascular conduits encompassing the commonly used species: baboons, sheep, pigs, dogs, rabbits, and rodents. Studies on the comparative hematology for these species relative to humans are summarized, and the hydrodynamic values for common implant locations are also compared. The large- and small-animal models are then explored, highlighting the characteristics of each that determine their relative utility in the assessment of vascular conduits. Where possible, the performance of expanded polytetrafluoroethylene is given in each animal and in each location to allow direct comparisons between species. New challenges in animal modeling are outlined for the assessment of tissue-engineered graft designs. Finally, recommendations are given for the selection of animal models for the assessment of future vascular conduits.
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Saeed D, Fukamachi K. In Vivo Preclinical Anticoagulation Regimens After Implantation of Ventricular Assist Devices. Artif Organs 2009; 33:491-503. [DOI: 10.1111/j.1525-1594.2009.00733.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Animal models for pediatric circulatory support device pre-clinical testing: National Heart, Lung, and Blood Institute Pediatric Assist Device Contractor's Meeting Animal Models Working Group. ASAIO J 2009; 55:6-9. [PMID: 19139652 DOI: 10.1097/mat.0b013e318198e11c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Undar A. International conference on pediatric mechanical circulatory support systems and pediatric cardiopulmonary perfusion: outcomes and future directions. ASAIO J 2008; 54:141-6. [PMID: 18356645 PMCID: PMC2646197 DOI: 10.1097/mat.0b013e318167afdd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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