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Belanger BL, Avery MB, Sen A, Eesa M, Mitha AP. Creating Clinically Relevant Aneurysm Sizes in the Rabbit Surgical Elastase Model. World Neurosurg 2021; 152:e173-e179. [PMID: 34116263 DOI: 10.1016/j.wneu.2021.05.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 05/16/2021] [Accepted: 05/17/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Creating aneurysm sizes in animal models that resemble human aneurysms is essential to study and test neuroendovascular devices. The commonly used rabbit surgical elastase model, however, produces saccular aneurysms that are smaller than those typically treated in humans. The goal of this study was to determine whether an increased vessel stump length and the addition of calcium chloride to the incubation solution has an effect on the resulting aneurysm size. METHODS Using a modified aneurysm creation method, 32 female New Zealand White rabbits underwent aneurysm creation procedures. Subjects were equally allocated into 4 different groups based on vessel stump length (2 cm controls vs. 3 cm) and incubation solution (elastase alone controls vs. a 1:1 mixture of elastase and calcium chloride). At 4 weeks, all animals underwent angiography to determine the resulting aneurysm size by a neurointerventionalist who was blinded to treatment group. RESULTS An increase in stump length from 2 cm to 3 cm resulted in a significant increase in the height of aneurysm (P < 0.05). Compared with control animals, the combination of a 3-cm stump length and the addition of calcium chloride to the incubation solution resulted in a significant increase in aneurysm height, width, and volume (P < 0.05). CONCLUSIONS Creating larger aneurysms is necessary for the rabbit model to be more clinically relevant. Our study demonstrated that the utilization of a 3-cm vessel stump as well as both calcium chloride and elastase in the incubation solution results in aneurysm sizes that more closely resemble the population of aneurysms treated in humans.
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Affiliation(s)
| | - Michael B Avery
- Pacific Neuroscience Institute, Providence Saint John's Health Center, Santa Monica, California, USA
| | - Arindom Sen
- Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Alberta, Canada
| | - Muneer Eesa
- Department of Radiology, Foothills Medical Centre, Calgary, Alberta, Canada; Department of Clinical Neurosciences, Foothills Medical Centre, Calgary, Alberta, Canada
| | - Alim P Mitha
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada; Department of Radiology, Foothills Medical Centre, Calgary, Alberta, Canada; Department of Clinical Neurosciences, Foothills Medical Centre, Calgary, Alberta, Canada.
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McCulloch A, Turcott A, Graham G, Frenklakh S, Cardinal KO. Endothelialized silicone aneurysm models for in vitro evaluation of flow diverters. J Neurointerv Surg 2020; 13:727-731. [PMID: 33106319 PMCID: PMC8292603 DOI: 10.1136/neurintsurg-2020-016859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/06/2020] [Accepted: 10/06/2020] [Indexed: 01/11/2023]
Abstract
Objective The goal of this work was to endothelialize silicone aneurysm tubes for use as in vitro models for evaluating endothelial cell interactions with neurovascular devices. The first objective was to establish consistent and confluent endothelial cell linings and to evaluate the silicone vessels over time. The second objective was to use these silicone vessels for flow diverter implantation and assessment. Methods Silicone aneurysm tubes were coated with fibronectin and placed into individual bioreactor systems. Human umbilical vein endothelial cells were deposited within tubes to create silicone vessels, then cultivated on a peristaltic pump and harvested at 2, 5, 7, or 10 days to evaluate the endothelial cell lining. A subset of silicone aneurysm vessels was used for flow diverter implantation, and evaluated for cell coverage over device struts at 3 or 7 days after deployment. Results Silicone vessels maintained confluent, PECAM-1 (platelet endothelial cell adhesion molecule 1) positive endothelial cell linings over time. These vessels facilitated and withstood flow diverter implantation, with robust cell linings disclosed after device deployment. Additionally, the endothelial cells responded to implanted devices through coverage of the flow diverter struts with increased cell coverage over the aneurysm seen at 7 days after deployment as compared with 3 days. Conclusions Silicone aneurysm models can be endothelialized and successfully maintained in vitro over time. Furthermore, these silicone vessels can be used for flow diverter implantation and assessment.
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Affiliation(s)
- Alyssa McCulloch
- Biomedical Engineering Department, Cal Poly, San Luis Obispo, California, USA
| | - Ashley Turcott
- Biomedical Engineering Department, Cal Poly, San Luis Obispo, California, USA
| | - Gabriella Graham
- Biomedical Engineering Department, Cal Poly, San Luis Obispo, California, USA
| | - Sergey Frenklakh
- Research and Development, Stryker Neurovascular Intervention, Fremont, California, USA
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Villadolid C, Puccini B, Dennis B, Gunnin T, Hedigan C, Cardinal KO. Custom tissue engineered aneurysm models with varying neck size and height for early stage in vitro testing of flow diverters. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2020; 31:34. [PMID: 32172490 PMCID: PMC7072062 DOI: 10.1007/s10856-020-06372-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/28/2020] [Indexed: 05/03/2023]
Abstract
Endovascular techniques for treating cerebral aneurysms are rapidly advancing and require testing to optimize device configurations. The purpose of this work was to customize tissue-engineered aneurysm "blood vessel mimics" (aBVMs) for early stage in vitro assessment of vascular cell responses to flow diverters and other devices. Aneurysm scaffolds with varying neck size and height were created through solid modeling, mold fabrication, mandrel creation, and electrospinning. Scaffold dimensions and fiber morphology were characterized. aBVMs were created by depositing human smooth muscle and endothelial cells within scaffolds, and cultivating within perfusion bioreactors. These vessels were left untreated or used for flow diverter implantation. Cellular responses to flow diverters were evaluated at 3 days. Custom scaffolds were created with aneurysm neck diameters of 2.3, 3.5, and 5.5 mm and with aneurysm heights of 2, 5, and 8 mm. A set of scaffolds with varying neck size was used for aBVM creation, and dual-sodding of endothelial and smooth muscle cells resulted in consistent and confluent cellular linings. Flow diverters were successfully implanted in a subset of aBVMs, and initial cell coverage over devices was seen in the parent vessel at 3 days. Direct visualization of the device over the neck region was feasible, supporting the future use of these models for evaluating and comparing flow diverter healing. Tissue-engineered aneurysm models can be created with custom neck sizes and heights, and used to evaluate cellular responses to flow diverters and other endovascular devices.
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Affiliation(s)
- Camille Villadolid
- Biomedical Engineering Department, Cal Poly, 1 Grand Ave, San Luis Obispo, CA, 93407, USA
| | - Brandon Puccini
- Mechanical Engineering Department, Cal Poly, 1 Grand Ave, San Luis Obispo, CA, 93407, USA
| | - Benjamin Dennis
- Biomedical Engineering Department, Cal Poly, 1 Grand Ave, San Luis Obispo, CA, 93407, USA
| | - Tessa Gunnin
- Biomedical Engineering Department, Cal Poly, 1 Grand Ave, San Luis Obispo, CA, 93407, USA
| | - Conor Hedigan
- Biomedical Engineering Department, Cal Poly, 1 Grand Ave, San Luis Obispo, CA, 93407, USA
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Herrmann AM, Meckel S, Gounis MJ, Kringe L, Motschall E, Mülling C, Boltze J. Large animals in neurointerventional research: A systematic review on models, techniques and their application in endovascular procedures for stroke, aneurysms and vascular malformations. J Cereb Blood Flow Metab 2019; 39:375-394. [PMID: 30732549 PMCID: PMC6421248 DOI: 10.1177/0271678x19827446] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neuroendovascular procedures have led to breakthroughs in the treatment of ischemic stroke, intracranial aneurysms, and intracranial arteriovenous malformations. Due to these substantial successes, there is continuous development of novel and refined therapeutic approaches. Large animal models feature various conceptual advantages in translational research, which makes them appealing for the development of novel endovascular treatments. However, the availability and role of large animal models have not been systematically described so far. Based on comprehensive research in two databases, this systematic review describes current large animal models in neuroendovascular research including their primary use. It may therefore serve as a compact compendium for researchers entering the field or looking for opportunities to refine study concepts. It also describes particular applications for ischemic stroke and aneurysm therapy, as well as for the treatment of arteriovenous malformations. It focuses on most promising study designs and readout parameters, as well as on important pitfalls in endovascular translational research including ways to circumvent them.
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Affiliation(s)
- Andrea M Herrmann
- 1 Department of Neuroradiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,2 Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, Leipzig University, Leipzig, Germany
| | - Stephan Meckel
- 1 Department of Neuroradiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthew J Gounis
- 3 Department of Radiology, New England Center for Stroke Research, University of Massachusetts Medical School, Worcester, MA, USA
| | - Leona Kringe
- 1 Department of Neuroradiology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,2 Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, Leipzig University, Leipzig, Germany
| | - Edith Motschall
- 4 Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center, University of Freiburg, Freiburg, Germany
| | - Christoph Mülling
- 2 Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, Leipzig University, Leipzig, Germany
| | - Johannes Boltze
- 5 School of Life Sciences, University of Warwick, UK.,6 Department of Translational Medicine and Cell Technology, Fraunhofer Research Institution for Marine Biotechnology and Cell Technology and Institute for Medical and Marine Biotechnology, University of Lübeck, Lübeck, Germany
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Greim-Kuczewski K, Berenstein A, Kis S, Hauser A, Killer-Oberpfalzer M. Surgical technique for venous patch aneurysms with no neck in a rabbit model. J Neurointerv Surg 2017; 10:118-121. [PMID: 28179542 DOI: 10.1136/neurintsurg-2016-012955] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 11/03/2022]
Abstract
BACKGROUND Animal experimental studies are crucial for the development of endovascular devices and embolization techniques for intracranial aneurysms. The aim of the study was to describe the surgical creation technique for an aneurysm with a dilated shape and no definable aneurysm neck. The model should be reproducible in size and shape and stay patent over a long period of time. It should constitute a challenge to endovascular therapy and provide a valuable testing environment for new endovascular devices and techniques. METHODS Surgical creation of 30 no-neck aneurysms was attempted in 15 New Zealand White rabbits using a segment of jugular vein, which was transected, longitudinally opened and sutured to the anterior aspect of the common carotid artery. The first 14 aneurysms were used to develop the technique. Once the technique was mastered and the procedure was standardized, 16 consecutive aneurysms were created. For these aneurysms, digital subtraction angiography was employed after a mean of 120 days to confirm size and patency. All aneurysms were evaluated for patency. RESULTS Overall aneurysm patency was 93%. Three complications occurred, two of which were related to the vascular anastomosis. Angiographic follow-up showed a median (SD) aneurysm base and height of 6.7 (0.76) mm and 3.2 (0.85) mm), respectively. CONCLUSIONS This technique allows creation of aneurysms without a neck which are reproducible in size and shape, and which remain patent. The model contributes to the list of aneurysm models fit for evaluation of embolization devices and techniques. It is particularly useful in exploring treatment options for wide-neck aneurysms and aneurysms which presently do not qualify for conventional coiling.
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Affiliation(s)
- Kilian Greim-Kuczewski
- Research Institute of Neurointervention, Paracelsus Medical University, Salzburg, Austria
| | - Alejandro Berenstein
- Department of Neurosurgery, Ichan School of Medicine, Mount Sinai, Health Care System, New York, New York, USA
| | - Sebastian Kis
- Research Institute of Neurointervention, Paracelsus Medical University, Salzburg, Austria
| | - Anna Hauser
- Research Institute of Neurointervention, Paracelsus Medical University, Salzburg, Austria.,Department of Neurosurgery, Kepler Universitätsklinikum, Neuromed Campus, Linz, Austria
| | - Monika Killer-Oberpfalzer
- Research Institute of Neurointervention, Paracelsus Medical University, Salzburg, Austria.,Department of Neurology, University Hospital, Salzburg, Austria
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Brinjikji W, Ding YH, Kallmes DF, Kadirvel R. From bench to bedside: utility of the rabbit elastase aneurysm model in preclinical studies of intracranial aneurysm treatment. J Neurointerv Surg 2016; 8:521-5. [PMID: 25904642 PMCID: PMC4932861 DOI: 10.1136/neurintsurg-2015-011704] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/06/2015] [Indexed: 11/03/2022]
Abstract
Preclinical studies are important in helping practitioners and device developers improve techniques and tools for endovascular treatment of intracranial aneurysms. Thus an understanding of the major animal models used in such studies is important. The New Zealand rabbit elastase induced arterial aneurysm of the common carotid artery is one of the most commonly used models in testing the safety and efficacy of new endovascular devices. In this review we discuss: (1) the various techniques used to create the aneurysm, (2) complications of aneurysm creation, (3) natural history of the arterial aneurysm, (4) histopathologic and hemodynamic features of the aneurysm, (5) devices tested using this model, and (6) weaknesses of the model. We demonstrate how preclinical studies using this model are applied in the treatment of intracranial aneurysms in humans. The model has similar hemodynamic, morphological, and histologic characteristics to human aneurysms, and demonstrates similar healing responses to coiling as human aneurysms. Despite these strengths, however, the model does have many weaknesses, including the fact that the model does not emulate the complex inflammatory processes affecting growing and ruptured aneurysms. Furthermore, the extracranial location of the model affects its ability to be used in preclinical safety assessments of new devices. We conclude that the rabbit elastase model has characteristics that make it a simple and effective model for preclinical studies on the endovascular treatment of intracranial aneurysms, but further work is needed to develop aneurysm models that simulate the histopathologic and morphologic characteristics of growing and ruptured aneurysms.
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Affiliation(s)
| | - Yong H Ding
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
| | - David F Kallmes
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA
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Krähenbühl AK, Gralla J, Abu-Isa J, Mordasini P, Widmer HR, Raabe A, Reinert M. High-flow venous pouch aneurysm in the rabbit carotid artery: A model for large aneurysms. Interv Neuroradiol 2015; 21:407-11. [PMID: 26015528 DOI: 10.1177/1591019915582381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Currently one of the most widely used models for the development of endovascular techniques and coiling devices for treatment of aneurysm is the elastase-induced aneurysm model in the rabbit carotid artery. Microsurgical techniques for creating an aneurysm with a venous pouch have also been established, although both techniques usually result in aneurysms less than 1 cm in diameter. We investigated whether an increase in blood flow toward the neck would produce larger aneurysms in a microsurgical venous pouch model. MATERIALS AND METHODS Microsurgical operations were performed on 11 New Zealand white rabbits. Both carotid arteries and the right jugular vein were dissected, and the right carotid artery was temporarily clipped followed by an arteriotomy. The left carotid artery was also clipped proximally, ligated distally, and sutured onto the proximal half of the arteriotomy in the right carotid artery. The venous graft was sutured onto the distal half of the arteriotomy. Digital subtraction angiography was also performed. RESULTS Angiography showed patent anastomosed vessels and aneurysms in the seven surviving rabbits. Mean aneurysm measurements among surviving rabbits with patent vessels were: 13.9 mm length, 9.3 mm width, and neck diameter 4.7 mm. The resulting mean aspect ratio was 3.35 and the mean bottleneck ratio was 3.05. CONCLUSION A large venous graft and increased blood flow toward the base of the aneurysm seem to be key factors in the creation of large venous pouch aneurysms. These large aneurysms allow testing of endovascular devices designed for large and giant aneurysms.
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Affiliation(s)
| | - Jan Gralla
- Institute for Neuroradiology, Bern University Hospital, Switzerland
| | - Janine Abu-Isa
- Department of Neurosurgery, Bern University Hospital, Switzerland
| | | | - Hans R Widmer
- Department of Neurosurgery, Bern University Hospital, Switzerland
| | - Andreas Raabe
- Department of Neurosurgery, Bern University Hospital, Switzerland
| | - Michael Reinert
- Department of Neurosurgery, Ospedale Civico di Lugano, Switzerland
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Ysuda R, Strother CM, Aagaard-Kienitz B, Pulfer K, Consigny D. A large and giant bifurcation aneurysm model in canines: proof of feasibility. AJNR Am J Neuroradiol 2011; 33:507-12. [PMID: 22194362 DOI: 10.3174/ajnr.a2789] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE To our knowledge, no reproducible animal model of a giant bifurcation type aneurysm has been described. It was our aim to develop a 1-stage and reproducible model of a venous pouch giant aneurysm in canines. MATERIALS AND METHODS Nine canines were involved. Bilateral CCAs were exposed. The left CCA was divided and its distal segment was swung to the right side. Using the right CCA and the distal segment of the left CCA, either a bifurcation or a terminal arterial structure was constructed. Bilateral external jugular veins were also exposed. A 30-mm vein segment was harvested from each side. Each vein graft was split and unfolded to make 2 venous sheets. These sheets were then joined top-to-bottom so as to form a single cylinder in such a way that original adventitial side of the venous sheets was on the exterior surface. In 2 instances, pieces of polytetrafluoroethylene were employed along with the venous sheets. The combined vein graft was then incorporated into the arterial anastomosis. Lastly, the top of the venous pouch was closed. No medications for anticoagulant or antiplatelet were used throughout the study period. Follow-up imaging studies were performed. RESULTS It took 2.5 hours on average for 2 operators to create an aneurysm. Eight of the 9 aneurysms were patent at follow-up. The cause of the spontaneous thrombosis was unclear despite autopsy. All the aneurysms had a maximum diameter >20 mm. CONCLUSIONS We demonstrated and illustrated a 1-stage and reproducible procedure to create a model of a venous pouch bifurcation giant aneurysm in canines.
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Affiliation(s)
- R Ysuda
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792-3252, USA
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