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Kiseleva EB, Sovetsky AA, Ryabkov MG, Gubarkova EV, Plekhanov AA, Bederina EL, Potapov AL, Bogomolova AY, Zaitsev VY, Gladkova ND. Detecting emergence of ruptures in individual layers of the stretched intestinal wall using optical coherence elastography: A pilot study. JOURNAL OF BIOPHOTONICS 2024:e202400086. [PMID: 38923316 DOI: 10.1002/jbio.202400086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/26/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
We report a new application of compression optical coherence elastography (C-OCE) to monitor the emergence of ruptures in individual layers of longitudinally stretched small-intestine walls using tissue samples (n = 36) from nine minipigs. Before stretching, C-OCE successfully estimated stiffness for each intestine-wall layer: longitudinal muscular layer with serosa, circumferential muscular layer, submucosa and mucosa. In stretched samples, C-OCE clearly visualized initial stiffening in both muscular layers. By 25% elongation, a sharp stiffness decrease for the longitudinal muscular layer, indicated emergence of tears in all samples. With further stretching, for most samples, ruptures emerged in the circumferential muscular layer and submucosa, while mucosa remained undamaged. Histology confirmed the OCE-revealed damaging and absence of tissue damage for ~15% elongation. Thus, C-OCE has demonstrated a high potential for determining the safety tissue-stretching threshold which afterward may be used intraoperatively to prevent rupture risk in intestinal tissues stretched during various diagnostic/therapeutic procedures.
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Affiliation(s)
- Elena B Kiseleva
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexander A Sovetsky
- Nonlinear Geophysical Processes Department, A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Maksim G Ryabkov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Ekaterina V Gubarkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Anton A Plekhanov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Evgeniya L Bederina
- University Clinic, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Arseniy L Potapov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexandra Y Bogomolova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Vladimir Y Zaitsev
- Nonlinear Geophysical Processes Department, A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Natalia D Gladkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
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Girardin L, Stokes C, Thet MS, Oo AY, Balabani S, Díaz-Zuccarini V. Patient-Specific Haemodynamic Analysis of Virtual Grafting Strategies in Type-B Aortic Dissection: Impact of Compliance Mismatch. Cardiovasc Eng Technol 2024; 15:290-304. [PMID: 38438692 PMCID: PMC11239731 DOI: 10.1007/s13239-024-00713-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 01/02/2024] [Indexed: 03/06/2024]
Abstract
INTRODUCTION Compliance mismatch between the aortic wall and Dacron Grafts is a clinical problem concerning aortic haemodynamics and morphological degeneration. The aortic stiffness introduced by grafts can lead to an increased left ventricular (LV) afterload. This study quantifies the impact of compliance mismatch by virtually testing different Type-B aortic dissection (TBAD) surgical grafting strategies in patient-specific, compliant computational fluid dynamics (CFD) simulations. MATERIALS AND METHODS A post-operative case of TBAD was segmented from computed tomography angiography data. Three virtual surgeries were generated using different grafts; two additional cases with compliant grafts were assessed. Compliant CFD simulations were performed using a patient-specific inlet flow rate and three-element Windkessel outlet boundary conditions informed by 2D-Flow MRI data. The wall compliance was calibrated using Cine-MRI images. Pressure, wall shear stress (WSS) indices and energy loss (EL) were computed. RESULTS Increased aortic stiffness and longer grafts increased aortic pressure and EL. Implementing a compliant graft matching the aortic compliance of the patient reduced the pulse pressure by 11% and EL by 4%. The endothelial cell activation potential (ECAP) differed the most within the aneurysm, where the maximum percentage difference between the reference case and the mid (MDA) and complete (CDA) descending aorta replacements increased by 16% and 20%, respectively. CONCLUSION This study suggests that by minimising graft length and matching its compliance to the native aorta whilst aligning with surgical requirements, the risk of LV hypertrophy may be reduced. This provides evidence that compliance-matching grafts may enhance patient outcomes.
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Affiliation(s)
- Louis Girardin
- Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, 43-45 Foley Street, London, W1W 7TS, UK
| | - Catriona Stokes
- Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, 43-45 Foley Street, London, W1W 7TS, UK
| | - Myat Soe Thet
- Department of Cardiothoracic Surgery, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Aung Ye Oo
- Department of Cardiothoracic Surgery, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Stavroula Balabani
- Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, 43-45 Foley Street, London, W1W 7TS, UK
| | - Vanessa Díaz-Zuccarini
- Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, 43-45 Foley Street, London, W1W 7TS, UK.
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Asciak L, Domingo-Roca R, Dow JR, Brodie R, Paterson N, Riches PE, Shu W, McCormick C. Exploiting light-based 3D-printing for the fabrication of mechanically enhanced, patient-specific aortic grafts. J Mech Behav Biomed Mater 2024; 154:106531. [PMID: 38588633 DOI: 10.1016/j.jmbbm.2024.106531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/10/2024]
Abstract
Despite polyester vascular grafts being routinely used in life-saving aortic aneurysm surgeries, they are less compliant than the healthy, native human aorta. This mismatch in mechanical behaviour has been associated with disruption of haemodynamics contributing to several long-term cardiovascular complications. Moreover, current fabrication approaches mean that opportunities to personalise grafts to the individual anatomical features are limited. Various modifications to graft design have been investigated to overcome such limitations; yet optimal graft functionality remains to be achieved. This study reports on the development and characterisation of an alternative vascular graft material. An alginate:PEGDA (AL:PE) interpenetrating polymer network (IPN) hydrogel has been produced with uniaxial tensile tests revealing similar strength and stiffness (0.39 ± 0.05 MPa and 1.61 ± 0.19 MPa, respectively) to the human aorta. Moreover, AL:PE tubular conduits of similar geometrical dimensions to segments of the aorta were produced, either via conventional moulding methods or stereolithography (SLA) 3D-printing. While both fabrication methods successfully demonstrated AL:PE hydrogel production, SLA 3D-printing was more easily adaptable to the fabrication of complex structures without the need of specific moulds or further post-processing. Additionally, most 3D-printed AL:PE hydrogel tubular conduits sustained, without failure, compression up to 50% their outer diameter and returned to their original shape upon load removal, thereby exhibiting promising behaviour that could withstand pulsatile pressure in vivo. Overall, these results suggest that this AL:PE IPN hydrogel formulation in combination with 3D-printing, has great potential for accelerating progress towards personalised and mechanically-matched aortic grafts.
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Affiliation(s)
- Lisa Asciak
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Roger Domingo-Roca
- Department of Electronic and Electric Engineering, University of Strathclyde, Glasgow, UK
| | - Jamie R Dow
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK; Research and Development, Terumo Aortic Ltd., Inchinnan, Glasgow, UK
| | - Robbie Brodie
- Research and Development, Terumo Aortic Ltd., Inchinnan, Glasgow, UK
| | - Niall Paterson
- Research and Development, Terumo Aortic Ltd., Inchinnan, Glasgow, UK
| | - Philip E Riches
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Wenmiao Shu
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
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Hireche K, Canaud L, Peyron PA, Sakhri L, Serres I, Kamel S, Lounes Y, Gandet T, Alric P. Ex Vivo Comparison of the Elastic Properties of Vascular Substitutes Used for Pulmonary Artery Replacement. J Surg Res 2024; 295:222-230. [PMID: 38039727 DOI: 10.1016/j.jss.2023.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 10/17/2023] [Accepted: 10/30/2023] [Indexed: 12/03/2023]
Abstract
INTRODUCTION Study aims were to evaluate the elastic properties of vascular substitutes frequently used for pulmonary artery (PA) replacement, and then to compare their compliance and stiffness indexes to those of human PA. METHODS A bench-test pulsatile flow experiment was developed to perfuse human cadaveric vascular substitutes (PA, thoracic aorta, human pericardial conduit), bovine pericardial conduit, and prosthetic vascular substitutes (polytetrafluorethylene and Dacron grafts) at a flow and low pulsed pressure mimicking pulmonary circulation. Intraluminal pressure was measured. An ultrasound system with an echo-tracking function was used to monitor vessel wall movements. The diameter, compliance, and stiffness index were calculated for each vascular substitute and compared to the human PA at mean pressures ranging from 10 to 50 mmHg. RESULTS The compliance of the PA and the thoracic aorta were similar at mean physiological pressures of 10 mmHg and 20 mmHg. The PA was significantly less compliant than the aorta at mean pressures above 30 mmHg (P = 0.017). However, there was no difference in stiffness index between the two substitutes over the entire pressure range. Compared to the PA, human pericardial conduit was less compliant at 10 mmHg (P = 0.033) and stiffer at 10 mmHg (P = 0.00038) and 20 mmHg (P = 0.026). Bovine pericardial conduit and synthetic prostheses were significantly less compliant and stiffer than the PA for mean pressures of 10, 20, and 30 mmHg. There were no differences at 40 and 50 mmHg. CONCLUSIONS Allogenic arterial grafts appear to be the most suitable vascular substitutes in terms of compliance and stiffness for PA replacement.
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Affiliation(s)
- Kheira Hireche
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France.
| | - Ludovic Canaud
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
| | - Pierre Antoine Peyron
- Department of Forensic Medicine, Lapeyronie University Hospital, Montpellier, France
| | - Linda Sakhri
- Groupe Hospitalier Mutualiste de grenoble, Daniel Hollard Cancer Institute, Grenoble, France
| | - Isabelle Serres
- Department of Anatomical Pathology, Gui De Chauliac Hospital, Montpellier, France
| | - Sanaa Kamel
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France
| | - Youcef Lounes
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
| | - Thomas Gandet
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France
| | - Pierre Alric
- Department of Thoracic and Vascular Surgery, Arnaud de Villeneuve University Hospital, Montpellier, France; PhyMedExp, University of Montpellier, INSERM, CNRS, Montpellier, France
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Jarrell DK, Jacot JG. An In Vitro Characterization of a PCL-Fibrin Scaffold for Myocardial Repair. MATERIALS TODAY. COMMUNICATIONS 2023; 37:107596. [PMID: 38130877 PMCID: PMC10732481 DOI: 10.1016/j.mtcomm.2023.107596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Each year in the United States approximately 10,000 babies are born with a complex congenital heart defect (CHD) requiring surgery in the first year of after birth. Several of these operations require the implantation of a full-thickness heart patch; however, the current patch materials available to pediatric heart surgeons are exclusively non-living and non-degradable, which do not grow with the patient and are prone to fail due to an inability to integrate with the heart. In this work, the goal was to develop a full-thickness, tissue engineered myocardial patch (TEMP) that is made from biodegradable components, strong enough to withstand the mechanical forces of the heart wall, and able to integrate with the heart and drive neotissue formation. Here, a thick and porous electrospun PCL scaffold filled with high-salt PEGylated fibrin was developed. The scaffold was found to be mechanically sufficient for heart wall repair. Vascular cells were able to infiltrate more than halfway through the scaffold in static culture within three weeks. The scaffold maintained pluripotent stem cells for at least four days, supports viable iPSC-derived cardiomyocytes, and fostered tissue thickening in vitro. The TEMP developed here and tested in vitro is promising for the repair of structural CHD and will next be assessed in situ.
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Affiliation(s)
- Dillon K Jarrell
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Jeffrey G Jacot
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
- Department of Pediatrics, Children’s Hospital Colorado
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Kim T, Tjahjadi NS, He X, van Herwaarden JA, Patel HJ, Burris NS, Figueroa CA. Three-Dimensional Characterization of Aortic Root Motion by Vascular Deformation Mapping. J Clin Med 2023; 12:4471. [PMID: 37445507 DOI: 10.3390/jcm12134471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/15/2023] Open
Abstract
The aorta is in constant motion due to the combination of cyclic loading and unloading with its mechanical coupling to the contractile left ventricle (LV) myocardium. This aortic root motion has been proposed as a marker for aortic disease progression. Aortic root motion extraction techniques have been mostly based on 2D image analysis and have thus lacked a rigorous description of the different components of aortic root motion (e.g., axial versus in-plane). In this study, we utilized a novel technique termed vascular deformation mapping (VDM(D)) to extract 3D aortic root motion from dynamic computed tomography angiography images. Aortic root displacement (axial and in-plane), area ratio and distensibility, axial tilt, aortic rotation, and LV/Ao angles were extracted and compared for four different subject groups: non-aneurysmal, TAA, Marfan, and repair. The repair group showed smaller aortic root displacement, aortic rotation, and distensibility than the other groups. The repair group was also the only group that showed a larger relative in-plane displacement than relative axial displacement. The Marfan group showed the largest heterogeneity in aortic root displacement, distensibility, and age. The non-aneurysmal group showed a negative correlation between age and distensibility, consistent with previous studies. Our results revealed a strong positive correlation between LV/Ao angle and relative axial displacement and a strong negative correlation between LV/Ao angle and relative in-plane displacement. VDM(D)-derived 3D aortic root motion can be used in future studies to define improved boundary conditions for aortic wall stress analysis.
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Affiliation(s)
- Taeouk Kim
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nic S Tjahjadi
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xuehuan He
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - J A van Herwaarden
- Department of Vascular Surgery, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands
| | - Himanshu J Patel
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nicholas S Burris
- Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - C Alberto Figueroa
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Surgery, University of Michigan, Ann Arbor, MI 48109, USA
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Zaitsev VY, Sovetsky AA, Matveyev AL, Matveev LA, Shabanov D, Salamatova VY, Karavaikin PA, Vassilevski YV. Application of compression optical coherence elastography for characterization of human pericardium: A pilot study. JOURNAL OF BIOPHOTONICS 2023; 16:e202200253. [PMID: 36397665 DOI: 10.1002/jbio.202200253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/23/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
The recent impressive progress in Compression Optical Coherence Elastography (C-OCE) demonstrated diverse biomedical applications, comprising ophthalmology, oncology, etc. High resolution of C-OCE enables spatially resolved characterization of elasticity of rather thin (thickness < 1 mm) samples, which previously was impossible. Besides Young's modulus, C-OCE enables obtaining of nonlinear stress-strain dependences for various tissues. Here, we report the first application of C-OCE to nondestructively characterize biomechanics of human pericardium, for which data of conventional tensile tests are very limited and controversial. C-OCE revealed pronounced differences among differently prepared pericardium samples. Ample understanding of the influence of chemo-mechanical treatment on pericardium biomechanics is very important because of rapidly growing usage of own patients' pericardium for replacement of aortic valve leaflets in cardio-surgery. The figure demonstrates differences in the tangent Young's modulus after glutaraldehyde-induced cross-linking for two pericardium samples. One sample was over-stretched during the preparation, which caused some damage to the tissue.
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Affiliation(s)
- Vladimir Y Zaitsev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander A Sovetsky
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Alexander L Matveyev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Lev A Matveev
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Dmitry Shabanov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Victoria Y Salamatova
- Sechenov University, Moscow, Russia
- Sirius University of Science and Technology, Sochi, Russia
| | | | - Yuri V Vassilevski
- Sechenov University, Moscow, Russia
- Sirius University of Science and Technology, Sochi, Russia
- Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russia
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Houben IB, Chu AKY, Yang B, Kim KM, Fukuhara S, van Herwaarden JA, Moll FL, Nordsletten DA, Figueroa CA, Burris NS, Patel HJ. Left ventricular remodeling following aortic root and ascending aneurysm repair. Front Cardiovasc Med 2022; 9:944786. [DOI: 10.3389/fcvm.2022.944786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 10/03/2022] [Indexed: 11/13/2022] Open
Abstract
ObjectiveAdverse left ventricular remodeling due to a mismatch between stiffness of native aortic tissue and current polyester grafts may be under-recognized. This study was conducted to evaluate the impact of proximal aortic replacement on adverse remodeling of the left ventricle.Materials and methodsAll aortic root and ascending aortic aneurysm patients were identified (n = 2,001, 2006–2019). The study cohort consisted of a subset of patients (n = 98) with two or more electrocardiogram (ECG)-gated CT angiograms, but without concomitant aortic valve disease or bicuspid aortic valve, connective tissue disease, acute aortic syndrome or prior history of aortic repair or mitral valve surgery. LV myocardial mass was measured from CT data and indexed to body surface area (LVMI). The study cohort was divided into a surgery group (n = 47) and a control group; optimal medical therapy group (OMT, n = 51).ResultsThe mean age was 60 ± 11 years (80% male). Beta-blocker use was significantly more frequent in the surgery group (89 vs. 57%, p < 0.001), whereas, all other antihypertensive drugs were more frequent in the OMT group. The average follow-up was 9.1 ± 4.0 months for the surgery group and 13.7 ± 6.3 months for the OMT group. Average LVMI at baseline was similar in both groups (p = 0.934). LVMI increased significantly in the surgery group compared to the OMT group (3.7 ± 4.1 vs. 0.6 ± 4.4 g/m2, p = 0.001). Surgery, baseline LVMI, age, and sex were found to be independent predictors of LVMI increased on multivariable analysis.ConclusionProximal aortic repair with stiff polyester grafts was associated with increased LV mass in the first-year post-operative and may promote long-term adverse cardiac remodeling. Further studies should be considered to evaluate the competing effects of aortic aneurysm related mortality against risks of long-term graft induced aortic stiffening and the potential implications on current size thresholds for intervention.
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Sun M, Elkhodiry M, Shi L, Xue Y, Abyaneh MH, Kossar AP, Giuglaris C, Carter SL, Li RL, Bacha E, Ferrari G, Kysar J, Myers K, Kalfa D. A biomimetic multilayered polymeric material designed for heart valve repair and replacement. Biomaterials 2022; 288:121756. [PMID: 36041938 PMCID: PMC9801615 DOI: 10.1016/j.biomaterials.2022.121756] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/02/2022] [Accepted: 08/17/2022] [Indexed: 01/03/2023]
Abstract
Materials currently used to repair or replace a heart valve are not durable. Their limited durability related to structural degeneration or thrombus formation is attributed to their inadequate mechanical properties and biocompatibility profiles. Our hypothesis is that a biostable material that mimics the structure, mechanical and biological properties of native tissue will improve the durability of these leaflets substitutes and in fine improve the patient outcome. Here, we report the development, optimization, and testing of a biomimetic, multilayered material (BMM), designed to replicate the native valve leaflets. Polycarbonate urethane and polycaprolactone have been processed as film, foam, and aligned fibers to replicate the leaflet's architecture and anisotropy, through solution casting, lyophilization, and electrospinning. Compared to the commercialized materials, our BMMs exhibited an anisotropic behavior and a closer mechanical performance to the aortic leaflets. The material exhibited superior biostability in an accelerated oxidization environment. It also displayed better resistance to protein adsorption and calcification in vitro and in vivo. These results will pave the way for a new class of advanced synthetic material with long-term durability for surgical valve repair or replacement.
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Affiliation(s)
- Mingze Sun
- Department of Surgery, Columbia University, New York, NY, USA
| | | | - Lei Shi
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Yingfei Xue
- Department of Surgery, Columbia University, New York, NY, USA
| | | | | | | | | | - Richard L. Li
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Emile Bacha
- Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Irving Medical Center, New York, NY, USA
| | | | - Jeffrey Kysar
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - Kristin Myers
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - David Kalfa
- Department of Surgery, Columbia University, New York, NY, USA,Division of Cardiac, Thoracic and Vascular Surgery, Section of Pediatric and Congenital Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Irving Medical Center, New York, NY, USA,Corresponding author. Pediatric Cardiac Surgery, New-York Presbyterian - Morgan Stanley Children’s Hospital, Columbia University Medical Center, 3959 Broadway, CHN-274, New York, NY, 10032, USA. (D. Kalfa)
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Aortic Arch Phenotypes in Double Outlet Right Ventricle (DORV)—Implications for Surgery and Multi-Modal Imaging. J Cardiovasc Dev Dis 2022; 9:jcdd9080262. [PMID: 36005426 PMCID: PMC9410073 DOI: 10.3390/jcdd9080262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/02/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Abnormal aortic arches (AAAs) cover a spectrum of malformations, including abnormal laterality, branching patterns, and flow-limiting narrowing, which themselves vary from tubular hypoplasia, through discrete coarctation, to complete interruption of the arch. Neonatal surgery within the first days of life is necessary for most of these morphologies. Patch aortoplasty is widely used as it can offer a good haemodynamic result, being tailored to each combination of presenting pathologies. Our study hypothesis was that arch malformations are frequent in DORV and exhibit a plethora of phenotypes. We reviewed 54 post-mortem heart specimens from the UCL Cardiac Archive, analysing morphological features that would potentially influence the surgical repair, and taking relevant measurements of surgical importance. AAAs were found in half of the specimens, including 22.2% with aortic arch narrowing. In total, 70% and 30% of narrow arches had a subpulmonary and subaortic interventricular defect, respectively. Z-scores were significantly negative for all cases with tubular hypoplasia. We concluded that arch malformations are a common finding among hearts with DORV. Surgery on the neonatal aortic arch in DORV, performed in conjunction with other interventions that aim to balance pulmonary to systemic flow (Qp/Qs), should be anticipated and form an important part of multi-modal imaging.
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Vahabli E, Mann J, Heidari BS, Lawrence‐Brown M, Norman P, Jansen S, Pardo EDJ, Doyle B. The Technological Advancement to Engineer Next-Generation Stent-Grafts: Design, Material, and Fabrication Techniques. Adv Healthc Mater 2022; 11:e2200271. [PMID: 35481675 DOI: 10.1002/adhm.202200271] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/04/2022] [Indexed: 12/12/2022]
Abstract
Endovascular treatment of aortic disorders has gained wide acceptance due to reduced physiological burden to the patient compared to open surgery, and ongoing stent-graft evolution has made aortic repair an option for patients with more complex anatomies. To date, commercial stent-grafts are typically developed from established production techniques with simple design structures and limited material ranges. Despite the numerous updated versions of stent-grafts by manufacturers, the reoccurrence of device-related complications raises questions about whether the current manfacturing methods are technically able to eliminate these problems. The technology trend to produce efficient medical devices, including stent-grafts and all similar implants, should eventually change direction to advanced manufacturing techniques. It is expected that through recent advancements, especially the emergence of 4D-printing and smart materials, unprecedented features can be defined for cardiovascular medical implants, like shape change and remote battery-free self-monitoring. 4D-printing technology promises adaptive functionality, a highly desirable feature enabling printed cardiovascular implants to physically transform with time to perform a programmed task. This review provides a thorough assessment of the established technologies for existing stent-grafts and provides technical commentaries on known failure modes. They then discuss the future of advanced technologies and the efforts needed to produce next-generation endovascular implants.
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Affiliation(s)
- Ebrahim Vahabli
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
| | - James Mann
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
| | - Behzad Shiroud Heidari
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies University of Western Australia Perth 6009 Australia
| | | | - Paul Norman
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- Medical School The University of Western Australia Perth 6009 Australia
| | - Shirley Jansen
- Curtin Medical School Curtin University Perth WA 6102 Australia
- Department of Vascular and Endovascular Surgery Sir Charles Gairdner Hospital Perth WA 6009 Australia
- Heart and Vascular Research Institute Harry Perkins Medical Research Institute Perth WA 6009 Australia
| | - Elena de Juan Pardo
- School of Engineering The University of Western Australia Perth 6009 Australia
- School of Mechanical Medical and Process Engineering Queensland University of Technology Brisbane Queensland 4059 Australia
- T3mPLATE Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth WA 6009 Australia
| | - Barry Doyle
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies University of Western Australia Perth 6009 Australia
- British Heart Foundation Centre for Cardiovascular Science The University of Edinburgh Edinburgh EH16 4TJ UK
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12
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Beck EC, Jarrell DK, Lyons AC, Vanderslice EJ, VeDepo MC, Jacot JG. Assessment of electrospun cardiac patches made with sacrificial particles and polyurethane-polycaprolactone blends. J Biomed Mater Res A 2021; 109:2154-2163. [PMID: 33876870 PMCID: PMC9827500 DOI: 10.1002/jbm.a.37201] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/25/2021] [Accepted: 04/07/2021] [Indexed: 01/11/2023]
Abstract
Congenital heart defects (CHDs) are the leading cause of death in live-born infants. Currently, patches used in the repair of CHDs are exclusively inert and non-degradable, which increases the risk of arrhythmia, follow-up surgeries, and sudden cardiac death. In this preliminary study, we sought to fabricate biodegradable scaffolds that can support cardiac regeneration in the repair of CHDs. We electrospun biodegradable scaffolds using various blends of polyurethane (PU) and polycaprolactone (PCL) with and without sacrificial poly(ethylene oxide) (PEO) particles and assessed the mechanical properties, cell infiltration levels, and inflammatory response in vitro (surface cell seeding) and in vivo (subcutaneous mouse implant). We hypothesized that a blend of the two polymers would preserve the low stiffness of PU as well as the high cell infiltration observed in PCL scaffolds. The inclusion of PU in the blends, even as low as 10%, decreased cell infiltration both in vitro and in vivo. The inclusion of sacrificial PEO increased pore sizes, reduced Young's moduli, and reduced the inflammatory response in all scaffold types. Collectively, we have concluded that a PCL patch electrospun with sacrificial PEO particles is the most promising scaffold for further assessment as in our heart defect model.
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Affiliation(s)
- Emily C. Beck
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Dillon K. Jarrell
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Anne C. Lyons
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Ethan J. Vanderslice
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Mitchell C. VeDepo
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus
| | - Jeffrey G. Jacot
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical Campus,Department of Pediatrics, Children’s Hospital Colorado
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13
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Dye-Mediated Photo-Oxidation Biomaterial Fixation: Analysis of Bioinductivity and Mechanical Properties of Bovine Pericardium for Use in Cardiac Surgery. Int J Mol Sci 2021; 22:ijms221910768. [PMID: 34639108 PMCID: PMC8509588 DOI: 10.3390/ijms221910768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/27/2021] [Accepted: 09/30/2021] [Indexed: 11/17/2022] Open
Abstract
Extracellular matrix bioscaffolds can influence the cardiac microenvironment and modulate endogenous cellular mechanisms. These materials can optimize cardiac surgery for repair and reconstruction. We investigated the biocompatibility and bioinductivity of bovine pericardium fixed via dye-mediated photo-oxidation on human cardiac fibroblast activity. We compared a dye-mediated photo-oxidation fixed bioscaffold to glutaraldehyde-fixed and non-fixed bioscaffolds reported in contemporary literature in cardiac surgery. Human cardiac fibroblasts from consenting patients were seeded on to bioscaffold materials to assess the biocompatibility and bioinductivity. Human cardiac fibroblast gene expression, secretome, morphology and viability were studied. Dye-mediated photo-oxidation fixed acellular bovine pericardium preserves human cardiac fibroblast phenotype and viability; and potentiates a pro-vasculogenic paracrine response. Material tensile properties were compared with biomechanical testing. Dye-mediated photo-oxidation fixed acellular bovine pericardium had higher compliance compared to glutaraldehyde-fixed bioscaffold in response to tensile force. The biocompatibility, bioinductivity, and biomechanical properties of dye-mediated photo-oxidation fixed bovine pericardium demonstrate its feasibility as a bioscaffold for use in cardiac surgery. As a fixed yet bioinductive solution, this bioscaffold demonstrates enhanced compliance and retains bioinductive properties that may leverage endogenous reparative pathways. Dye-mediated photo-oxidation fixed bioscaffold warrants further investigation as a viable tool for cardiac repair and reconstruction.
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14
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Concannon J, Moerman KM, Hynes N, Sultan S, McGarry JP. Influence of shape-memory stent grafts on local aortic compliance. Biomech Model Mechanobiol 2021; 20:2373-2392. [PMID: 34541627 PMCID: PMC8595172 DOI: 10.1007/s10237-021-01514-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/18/2021] [Indexed: 12/19/2022]
Abstract
The effect of repair techniques on the biomechanics of the aorta is poorly understood, resulting in significant levels of postoperative complications for patients worldwide. This study presents a computational analysis of the influence of Nitinol-based devices on the biomechanical performance of a healthy patient-specific human aorta. Simulations reveal that Nitinol stent-grafts stretch the artery wall so that collagen is stretched to a straightened high-stiffness configuration. The high-compliance regime (HCR) associated with low diastolic lumen pressure is eliminated, and the artery operates in a low-compliance regime (LCR) throughout the entire cardiac cycle. The slope of the lumen pressure–area curve for the LCR post-implantation is almost identical to that of the native vessel during systole. This negligible change from the native LCR slope occurs because the stent-graft increases its diameter from the crimped configuration during deployment so that it reaches a low-stiffness unloading plateau. The effective radial stiffness of the implant along this unloading plateau is negligible compared to the stiffness of the artery wall. Provided the Nitinol device unloads sufficiently during deployment to the unloading plateau, the degree of oversizing has a negligible effect on the pressure–area response of the vessel, as each device exerts approximately the same radial force, the slope of which is negligible compared to the LCR slope of the native artery. We show that 10% oversizing based on the observed diastolic diameter in the mid descending thoracic aorta results in a complete loss of contact between the device and the wall during systole, which could lead to an endoleak and stent migration. 20% oversizing reaches the Dacron enforced area limit (DEAL) during the pulse pressure and results in an effective zero-compliance in the later portion of systole.
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Affiliation(s)
- J Concannon
- Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland
| | - K M Moerman
- Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland
| | - N Hynes
- Western Vascular Institute, National University of Ireland Galway, Galway, Ireland
| | - S Sultan
- Western Vascular Institute, National University of Ireland Galway, Galway, Ireland
| | - J P McGarry
- Biomedical Engineering, College of Engineering and Informatics, National University of Ireland, Galway, Ireland.
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15
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Sieren MM, Balks MF, Schlueter JK, Wegner F, Huellebrand M, Scharfschwerdt M, Barkhausen J, Frydrychowicz A, Gabbert DD, Oechtering TH. Comprehensive analysis of haemodynamics in patients with physiologically curved prostheses of the ascending aorta. Eur J Cardiothorac Surg 2021; 62:6354573. [PMID: 34409435 DOI: 10.1093/ejcts/ezab352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 06/22/2021] [Accepted: 06/25/2021] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES This is a comprehensive analysis of haemodynamics after valve-sparing aortic root replacement (VSARR) with anatomically curved prosthesis (CP) compared to straight prosthesis (SP) and age-matched volunteers (VOL) using 4D flow MRI (time-resolved three-dimensional magnetic resonance phase-contrast imaging). METHODS Nine patients with 90° CP, nine patients with SP, and twelve VOL were examined with 4D flow MRI. Analyses included various characteristic anatomical, qualitative and quantitative haemodynamic parameters. RESULTS Grading of secondary flow patterns was lower in CP patients than in SP patients (P = 0.09) and more comparable to VOL, albeit not reaching statistical significance. However, it was easy to differentiate between VSARR patients and healthy volunteers: Patients more often had angular aortic arches (CP: 89%, SP: 100%; VOL: 17%; P ≤ 0.002), increased average curvature (CP: 0.17/cm [0.15, 0.18]; SP: 0.15/cm [0.14, 0.16]; VOL: 0.14/cm [0.13, 0.16]; P ≤ 0.007; values given as median [interquartile range]), and more secondary flow patterns (CP: 3 [2, 4] SP: 3 [2, 3] VOL: 2 [1, 2]; P < 0.01). Maximum circulation (CP: 142.7 cm2/s [116.1, 187.3]; SP: 101.8 cm2/s [77.7, 132.5]; VOL: 42.8cm2/s [39.3, 65.6]; P ≤ 0.002), maximum helicity density (CP: 9.6 m/s2 [9.3, 23.9]; SP: 9.7 m/s2 [8.6, 12.5]; VOL 4.9 m/s2 [4.2, 7.7]; P ≤ 0.007), and wall shear stress gradient (e.g., proximal ascending aorta CP: 0.97 N/m2 [0.54, 1.07]; SP: 1.08 N/m2 [0.74, 1.24]; VOL: 0.41 N/m2 [0.32, 0.60]; P ≤ 0.01) were increased in patients. One CP patient had a round aortic arch with physiological haemodynamic parameters. CONCLUSIONS The restoration of physiological aortic configuration and haemodynamics was not fully achieved with the curved prostheses in our study cohort. However, there was a tendency towards improved haemodynamic conditions in the patients with curved prostheses overall but without statistical significance. A single patient with a CP and near-physiological configuration of the thoracic aorta underlines the importance of optimizing postoperative geometric conditions for allowing for physiological haemodynamics and cardiovascular energetics after VSARR.
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Affiliation(s)
- Malte Maria Sieren
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany
| | | | | | - Franz Wegner
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany
| | | | | | - Jörg Barkhausen
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany
| | - Alex Frydrychowicz
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany
| | - Dominik Daniel Gabbert
- Department of Congenital Heart Disease and Pediatric Cardiology, University Hospital of Schleswig-Holstein, Campus Kiel, Germany
| | - Thekla Helene Oechtering
- Department of Radiology and Nuclear Medicine, Universität zu Lübeck, Lübeck, Germany.,Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA
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16
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Houben IB, Nama N, Moll FL, van Herwaarden JA, Nordsletten DA, Williams DM, Patel HJ, Figueroa CA, Burris NS. Mapping pre-dissection aortic wall abnormalities: a multiparametric assessment. Eur J Cardiothorac Surg 2021; 57:1061-1067. [PMID: 31995165 DOI: 10.1093/ejcts/ezz381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/17/2019] [Accepted: 12/22/2019] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Maximal aortic diameter is commonly used to assess aortic risk but poorly predicts the timing and location of dissection events in patients with connective tissue disease who undergo regular imaging surveillance. Hence, we aimed to use available surveillance computed tomography angiography (CTA) scans to investigate the correlation between 3-dimensional (3D) growth and cyclic transmural wall stress with the location of intimal tear formation. METHODS Three type B aortic dissection patients with 2 available electrocardiogram (ECG)-gated pre-dissection CTA scans and without surgical repair during the pre-dissection interval were retrospectively identified at our institution. Vascular deformation mapping was used to measure 3D aortic growth between 2 pre-dissection clinical CTA studies. In addition, we performed a computational analysis to estimate cyclic transmural wall stress in patient-specific baseline CTA geometries. RESULTS In all 3 connective tissue disease patients, the site of type B aortic intimal tear co-localized with areas of peak 3D aortic wall growth. Aortic growth was detected by clinical radiological assessment in only 1 case. Co-localization of peak transmural stress and the site of intimal tear formation were found in all cases. CONCLUSIONS Focal areas of growth and transmural wall stress co-localized with the site of intimal tear formation. These hypothesis-generating results suggest a possible new analytic pathway for a more sophisticated assessment of the factors leading to the initiation of dissection in patients with connective tissue disease. These methods could improve on current risk-stratification techniques.
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Affiliation(s)
- Ignas B Houben
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Nitesh Nama
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Frans L Moll
- Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - David A Nordsletten
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - David M Williams
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Himanshu J Patel
- Department of Cardiac Surgery, University of Michigan, Ann Arbor, MI, USA
| | - C Alberto Figueroa
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
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17
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Legerer C, Stevens M, Vazquez GM, Müller T, Ferrington L. An experimental evaluation of a concept to improve conventional aortic prostheses. J Biomech 2020; 112:110010. [PMID: 32977296 DOI: 10.1016/j.jbiomech.2020.110010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/31/2020] [Accepted: 08/18/2020] [Indexed: 11/18/2022]
Abstract
Conventionally used textile prosthesis for traditional open surgical repair (OSR) of aortic aneurysms have a lower compliance than the native aortic tissue. Graft placements lead to an acute drop in compliance which effects cardiovascular risk and the development of graft related complications. A custom-made spring casing was applied to a Dacron graft segment under physiological pressure conditions within a five-element biventricular mock circulation loop, to investigate experimentally a concept to improve the compliance of a conventional aortic prosthesis by changing the transverse graft cross-section. Two different prosthesis locations, proximal and distal of compliant silicone tubing were used to study uniaxial graft compression with an elastic device. To characterise the devices' performance by means of pulse pressure (PP), diastolic pressure (Pdia) and pulse wave velocity(PWV), fluid pressures and flow were recorded. In a proximal graft setting (ascending aorta repair) elastic uniaxial compression with a custom-made spring casing (2 cm width) could significantly reduce PP by 10-14% (p < .001) and slowed PWV from 6.7 to 5.2 m/s (22%, p = .002). Applied to a graft in a distal position, the spring casing demonstrated less impact on PP (2-10%), but significantly reduced PWV in this mock aorta segment from 13.7 to 5.5 m/s (60%, p = .004). In conclusion, a newly conceptualised spring casing applied to the external wall of synthetic aortic grafts can reduce PP and slow PWV. By restoring elastic aortic recoil in stiff textile aortic prostheses, the presented concept is a potential solution to improve long-term aortic prosthesis related complications.
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Affiliation(s)
- C Legerer
- Rural Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia.
| | - M Stevens
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - G M Vazquez
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - T Müller
- Medical University of Graz, 8036 Graz, Austria
| | - L Ferrington
- Rural Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia
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18
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Whelan A, Williams E, Nolan DR, Murphy B, Gunning PS, O'Reilly D, Lally C. Bovine Pericardium of High Fibre Dispersion Has High Fatigue Life and Increased Collagen Content; Potentially an Untapped Source of Heart Valve Leaflet Tissue. Ann Biomed Eng 2020; 49:1022-1032. [PMID: 33063231 DOI: 10.1007/s10439-020-02644-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 09/30/2020] [Indexed: 02/07/2023]
Abstract
Bioprosthetic heart valves (BHVs) are implanted in aortic valve stenosis patients to replace the native, dysfunctional valve. Yet, the long-term performance of the glutaraldehyde-fixed bovine pericardium (GLBP) leaflets is known to reduce device durability. The aim of this study was to investigate a type of commercial-grade GLBP which has been over-looked in the literature to date; that of high collagen fibre dispersion (HD). Under uniaxial cyclic loading conditions, it was observed that the fatigue behaviour of HD GLBP was substantially equivalent to GLBP in which the fibres are highly aligned along the loading direction. It was also found that HD GLBP had a statistically significant 9.5% higher collagen content when compared to GLBP with highly aligned collagen fibres. The variability in diseased BHV delivery sites results in unpredictable and complex loading patterns across leaflets in vivo. This study presents the possibility of a shift from the traditional choice of circumferentially aligned GLBP leaflets, to that of high fibre dispersion arrangements. Characterised by its high fatigue life and increased collagen content, in addition to multiple fibre orientations, GLBP of high fibre dispersion may provide better patient outcomes under the multi-directional loading to which BHV leaflets are subjected in vivo.
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Affiliation(s)
- Alix Whelan
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland.,Structural Heart Division, Boston Scientific Corporation, Galway, Ireland
| | - Elizabeth Williams
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - David R Nolan
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - Bruce Murphy
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland.,Advanced Materials and Bioengineering Research Centre (AMBER), Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland
| | - Paul S Gunning
- Structural Heart Division, Boston Scientific Corporation, Los Gatos, CA, 95032, USA
| | - David O'Reilly
- Structural Heart Division, Boston Scientific Corporation, Galway, Ireland
| | - Caitríona Lally
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland. .,Department of Mechanical, Manufacturing & Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland. .,Advanced Materials and Bioengineering Research Centre (AMBER), Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland.
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19
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Amabili M, Balasubramanian P, Ferrari G, Franchini G, Giovanniello F, Tubaldi E. Identification of viscoelastic properties of Dacron aortic grafts subjected to physiological pulsatile flow. J Mech Behav Biomed Mater 2020; 110:103804. [DOI: 10.1016/j.jmbbm.2020.103804] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 04/12/2020] [Accepted: 04/15/2020] [Indexed: 11/26/2022]
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20
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Tsygankov YM, Zhorzholiani ST, Khugaev GA, Tevosov DR, Shepelev AD, Krasheninnikov SV, Gorodkov AY, Bockeria LA. The Effect of Mechanical Properties of Synthetic Prostheses Made by Electrospinning on the Results of Experimental Implantation in the Infrarenal Abdominal Aorta. Ann Vasc Surg 2020; 70:506-516. [PMID: 32890640 DOI: 10.1016/j.avsg.2020.08.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The research aims to study the effect of circumferential compliance of synthetic vascular prostheses on their healing during implantation in the infrarenal abdominal aorta of pigs. METHODS In an experiment, 12 pigs were implanted with blood vessel prostheses in the infrarenal abdominal aorta. The prostheses possessed elastic characteristics obtained by a tensile testing machine, and differed in circumferential compliance: rigid (polycaprolactone [PCL]); less compliant than the native aorta (polyurethane [PU]); comparable in compliance to the native aorta (copolymer of vinylidene fluoride with hexafluoropropylene) before (FKM) and after radiation treatment (FKM-γ). The implanted prostheses compliance was measured by aortography during the first 3 days and 1 month after implantation, the condition of the prosthesis capsule was evaluated by macroscopic preparations and histologic examination. RESULTS Pulsation on PCL prostheses was nonexistent immediately after implantation. On PU prostheses, slight pulsation was noted during the first 3 days and disappeared after 1 month. On FKM prostheses, although pulsation persisted after 1 month, a significant expansion of prostheses was also recorded as a result of fatigue plastic deformation. On FKM-γ prostheses, pulsation comparable in magnitude with aortic pulsation was present 1 month after implantation with no change in the size of the prosthesis. Macroscopic preparations reveal significant differences in the formed connective tissue capsule. The PCL prosthesis capsule is thick, narrowing the lumen of the vessel from the outside. The outer surface of PU prostheses is covered with a thinner uniform fibrous capsule. The inner surface of the FKM and FKM-γ prostheses is covered with a thin layer of smooth whitish tissue. The FKM prosthesis, unlike the FKM-γ prosthesis, is sharply expanded. In all cases, moderate aortic expansion was observed distal to the prosthesis. According to the histologic data, the outer and inner capsules of PCL prostheses are covered with a thick layer of fibrous tissue with signs of productive inflammation and foci of calcification. PU prostheses are surrounded by a thick connective tissue capsule partially endothelialized from the inside; the outer capsule is randomly populated with fibroblastic cells. FKM prostheses have a thin outer capsule where smooth muscle cells are visible, mainly oriented along and across the prosthesis axis; the inner capsule is thin and completely covered with a layer of endothelial cells from the side of the lumen. A layered structure is visible in the prosthesis capsule of FKM-γ, and the fibroblast cells in each layer of the capsule are oriented along or across the prosthesis axis, similar to the structure of a natural arterial vessel. The inner surface of the prosthesis is completely endothelialized. CONCLUSIONS The healing and degree of inflammation in a capsule of blood vessel prostheses implanted in the infrarenal abdominal aorta of pigs depend on the degree of their circumferential compliance. Although maintaining pulsations, the cellular structure of the capsule is characterized by a greater degree of differentiation and approaches the structure of the native arterial wall.
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Affiliation(s)
- Yuriy M Tsygankov
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia.
| | - Shota T Zhorzholiani
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia
| | - Georgiy A Khugaev
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia
| | - David R Tevosov
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia
| | | | | | - Alexandre Y Gorodkov
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia
| | - Leo A Bockeria
- Bakulev National Medical Research Center of Cardiovascular Surgery of the Ministry of Health of the Russian Federation (Head - E.Z.Goluhova, RAS), Moscow, Russia
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21
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Kizilski SB, Amili O, Coletti F, Faizer R, Barocas VH. Conceptual Framework Development for a Double-Walled Aortic Stent-Graft to Manage Blood Pressure. J Med Device 2020; 14:031005. [PMID: 32983314 DOI: 10.1115/1.4047873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 06/03/2020] [Indexed: 11/08/2022] Open
Abstract
A double-walled stent-graft (DWSG) design with a compressible gas layer was conceived with the goal of treating hypertension in patients receiving an aortic stent-graft. Early prototypes were developed to evaluate the design concept through static measurements from a finite element (FE) model and quasi-static inflation experiments, and through dynamic measurements from an in vitro flow loop and the three-element Windkessel model. The amount of gas in the gas layer and the properties of the flexible inner wall were the primary variables evaluated in this study. Properties of the inner wall had minimal effect on DWSG behavior, but increased gas charge led to increased fluid capacitance and larger reduction in peak and pulse pressures. In the flow loop, placement of the DWSG decreased pulse pressure by over 20% compared to a rigid stent-graft. Capacitance measurements were consistent across all methods, with the maximum capacitance estimated at 0.07 mL/mmHg for the largest gas charge in the 15 cm long prototype. Windkessel model predictions for in vivo performance of a DWSG placed in the aorta of a hypertensive patient showed pulse pressure reduction of 14% compared to a rigid stent-graft case, but pressures never returned to unstented values. These results indicate that the DWSG design has potential to be developed into a new treatment for hypertensive patients requiring an aortic intervention.
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Affiliation(s)
- Shannen B Kizilski
- Department of Mechanical Engineering, University of Minnesota, 312 Church Street SE Hasselmo Hall, 7-105, Minneapolis, MN 55455
| | - Omid Amili
- Department of Aerospace Engineering and Mechanics, University of Minnesota, 110 Union Street SE Akerman Hall, Minneapolis, MN 55455
| | - Filippo Coletti
- Department of Aerospace Engineering and Mechanics, University of Minnesota, 110 Union Street SE Akerman Hall, Minneapolis, MN 55455
| | - Rumi Faizer
- Department of Surgery, University of Minnesota, 909 Fulton Street SE, Minneapolis, MN 55455
| | - Victor H Barocas
- Department of Biomedical Engineering, University of Minnesota, 312 Church Street SE Hasselmo Hall, 7-105, Minneapolis, MN 55455
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22
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Pomeraniec L, Benayahu D. Mesenchymal Cell Growth and Differentiation on a New Biocomposite Material: A Promising Model for Regeneration Therapy. Biomolecules 2020; 10:biom10030458. [PMID: 32188110 PMCID: PMC7175166 DOI: 10.3390/biom10030458] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 01/13/2023] Open
Abstract
Mesenchymal stem cells serve as the body’s reservoir for healing and tissue regeneration. In cases of severe tissue trauma where there is also a need for tissue organization, a scaffold may be of use to support the cells in the damaged tissue. Such a scaffold should be composed of a material that can biomimic the mechanical and biological properties of the target tissues in order to support autologous cell-adhesion, their proliferation, and differentiation. In this study, we developed and assayed a new biocomposite made of unique collagen fibers and alginate hydrogel that was assessed for the ability to support mesenchymal cell-proliferation and differentiation. Analysis over 11 weeks in vitro demonstrated that the scaffold was biocompatible and supports the cells viability and differentiation to produce tissue-like structures or become adipocyte under differentiation medium. When the biocomposite was enriched with nano particles (NPs), mesenchymal cells grew well after uptake of fluorescein isothiocyanate (FITC) labeled NPs, maintained their viability, migrated through the biocomposite, reached, and adhered to the tissue culture dish. These promising findings revealed that the scaffold supports the growth and differentiation of mesenchymal cells that demonstrate their full physiological function with no sign of material toxicity. The cells’ functionality performance indicates and suggests that the scaffold is suitable to be developed as a new medical device that has the potential to support regeneration and the production of functional tissue.
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Palumbo MC, Rong LQ, Kim J, Navid P, Sultana R, Butcher J, Redaelli A, Roman MJ, Devereux RB, Girardi LN, Gaudino MFL, Weinsaft JW. Prosthetic aortic graft replacement of the ascending thoracic aorta alters biomechanics of the native descending aorta as assessed by transthoracic echocardiography. PLoS One 2020; 15:e0230208. [PMID: 32163486 PMCID: PMC7067394 DOI: 10.1371/journal.pone.0230208] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/24/2020] [Indexed: 01/16/2023] Open
Abstract
Introduction In patients with ascending aortic (AA) aneurysms, prosthetic graft replacement yields benefit but risk for complications in the descending aorta persists. Longitudinal impact of AA grafts on native descending aortic physiology is poorly understood. Methods Transthoracic echocardiograms (echo) in patients undergoing AA elective surgical grafting were analyzed: Descending aortic deformation indices included global circumferential strain (GCS), time to peak (TTP) strain, and fractional area change (FAC). Computed tomography (CT) was used to assess aortic wall thickness and calcification. Results 46 patients undergoing AA grafting were studied; 65% had congenital or genetically-associated AA (30% bicuspid valve, 22% Marfan, 13% other): After grafting (6.4±7.5 months), native descending aortic distension increased, irrespective of whether assessed based on circumferential strain or area-based methods (both p<0.001). Increased distensibility paralleled altered kinetics, as evidenced by decreased time to peak strain (p = 0.01) and increased velocity (p = 0.002). Augmented distensibility and flow velocity occurred despite similar pre- and post-graft blood pressure and medications (all p = NS), and was independent of pre-surgical aortic regurgitation or change in left ventricular stroke volume (both p = NS). Magnitude of change in GCS and FAC was 5–10 fold greater among patients with congenital or genetically associated AA vs. degenerative AA (p<0.001), paralleling larger descending aortic size, greater wall thickness, and higher prevalence of calcific atherosclerotic plaque in the degenerative group (all p<0.05). In multivariate analysis, congenital/genetically associated AA etiology conferred a 4-fold increment in magnitude of augmented native descending aortic strain after proximal grafting (B = 4.19 [CI 1.6, 6.8]; p = 0.002) independent of age and descending aortic size. Conclusions Prosthetic graft replacement of the ascending aorta increases magnitude and rapidity of distal aortic distension. Graft effects are greatest with congenital or genetically associated AA, providing a potential mechanism for increased energy transmission to the native descending aorta and adverse post-surgical aortic remodeling.
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Affiliation(s)
- Maria C. Palumbo
- Departments of Cardiothoracic Surgery, Weill Cornell Medicine, New York, New York, United States of America
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Lisa Q. Rong
- Department of Anesthesiology, Weill Cornell Medicine, New York, New York, United States of America
| | - Jiwon Kim
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
| | - Pedram Navid
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
| | - Razia Sultana
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
| | - Jonathan Butcher
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Mary J. Roman
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
| | - Richard B. Devereux
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
| | - Leonard N. Girardi
- Departments of Cardiothoracic Surgery, Weill Cornell Medicine, New York, New York, United States of America
| | - Mario F. L. Gaudino
- Departments of Cardiothoracic Surgery, Weill Cornell Medicine, New York, New York, United States of America
| | - Jonathan W. Weinsaft
- Department of Medicine (Cardiology), Weill Cornell Medicine, New York, New York, United States of America
- * E-mail:
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Walker S, Dittfeld C, Jakob A, Schönfelder J, König U, Tugtekin SM. Sterilization and Cross-Linking Combined with Ultraviolet Irradiation and Low-Energy Electron Irradiation Procedure: New Perspectives for Bovine Pericardial Implants in Cardiac Surgery. Thorac Cardiovasc Surg 2020; 70:33-42. [PMID: 32114687 DOI: 10.1055/s-0040-1705100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND Bovine pericardium is the major natural source of patches and aortic valve substitutes in cardiac repair procedures. However, long-term tissue durability and biocompatibility issues lead to degeneration (e.g., calcification) that requires reoperation. Tissue preparation strategies, including glutaraldehyde fixation, are reasons for the deterioration of pericardial tissues. We describe a pretreatment procedure involving sterilization and cross-linking combined with ultraviolet (UV) irradiation and low-energy electron irradiation (SULEEI). This innovative, glutaraldehyde-free protocol improves the mechanical aspects and biocompatibility of porcine pericardium patches. METHODS We adopted the SULEEI protocol, which combines decellularization, sterilization, and cross-linking, along with UV irradiation and low-energy electron irradiation, to pretreat bovine pericardium. Biomechanics, such as ultimate tensile strength and elasticity, were investigated by comparing SULEEI-treated tissue with glutaraldehyde-fixed analogues, clinical patch materials, and an aortic valve substitute. Histomorphological and cellular aspects were investigated by histology, DNA content analysis, and degradability. RESULTS Mechanical parameters, including ultimate tensile strength, elasticity (Young's modulus), and suture retention strength, were similar for SULEEI-treated and clinically applied bovine pericardium. The SULEEI-treated tissues showed well-preserved histoarchitecture that resembled all pericardial tissues investigated. Fiber density did not differ significantly. DNA content after the SULEEI procedure was reduced to less than 10% of the original tissue material, and more than 50% of the SULEEI-treated pericardium was digested by collagenase. CONCLUSION The SULEEI procedure represents a new treatment protocol for the preparation of patches and aortic valve prostheses from bovine pericardial tissue. The avoidance of glutaraldehyde fixation may lessen the tissue degeneration processes in cardiac repair patches and valve prostheses.
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Affiliation(s)
- Simona Walker
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Claudia Dittfeld
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Aline Jakob
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Jessy Schönfelder
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Ulla König
- Department of Medical and Biotechnological Applications, Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology, Dresden, Germany
| | - Sems-Malte Tugtekin
- Department of Cardiac Surgery, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
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Zhalmuratova D, La TG, Yu KTT, Szojka ARA, Andrews SHJ, Adesida AB, Kim CI, Nobes DS, Freed DH, Chung HJ. Mimicking "J-Shaped" and Anisotropic Stress-Strain Behavior of Human and Porcine Aorta by Fabric-Reinforced Elastomer Composites. ACS APPLIED MATERIALS & INTERFACES 2019; 11:33323-33335. [PMID: 31464413 DOI: 10.1021/acsami.9b10524] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An ex vivo heart perfusion device preserves the donor heart in a warm beating state during transfer between extraction and implantation surgeries. One of the current challenges includes the use of rigid and noncompliant plastic tubes, which causes injuries to the heart at the junction between the tissue and the tube. The compliant and rapidly strain-stiffening mechanical property that generates a "J-shaped" stress-strain behavior is necessary for producing the Windkessel effect, which ensures continuous flow of blood through the aorta. In this study, we mimic the J-shaped and anisotropic stress-strain behavior of human aorta in synthetic elastomers to replace the problematic noncompliant plastic tube. First, we assess the mechanical properties of human (n = 1) and porcine aorta (n = 14) to quantify the nonlinear and anisotropic behavior under uniaxial tensile stress from five different regions of the aorta. Second, fabric-reinforced elastomer composites were prepared by reinforcing silicone elastomers with embedded fabrics in a trilayer geometry. The knitted structures of the fabric provide strain-stiffening as well as anisotropic mechanical properties of the resulting composite in a deterministic manner. By optimizing the combination between different elastomers and fabrics, the resulting composites matched the J-shaped and anisotropic stress-strain behavior of natural human and porcine aorta. Finally, improved analytical constitutive models based on Gent's and Mooney-Rivlin's constitutive model (to describe the elastomer matrix) combined with Holzapfel-Gasser-Ogden's model (to represent the stiffer fabrics) were developed to describe the J-shaped behavior of the natural aortas and the fabric-reinforced composites. We anticipate that the suggested fabric-reinforced silicone elastomer composite design concept can be used to develop complex soft biomaterials, as well as in emerging engineering fields such as soft robotics and microfluidics, where the Windkessel effect can be useful in regulating the flow of fluids.
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Affiliation(s)
| | | | | | - Alexander R A Szojka
- Department of Surgery , University of Alberta , Edmonton , Alberta T6G 2E1 , Canada
| | - Stephen H J Andrews
- Department of Surgery , University of Alberta , Edmonton , Alberta T6G 2E1 , Canada
| | - Adetola B Adesida
- Department of Surgery , University of Alberta , Edmonton , Alberta T6G 2E1 , Canada
| | | | | | - Darren H Freed
- Department of Surgery , University of Alberta , Edmonton , Alberta T6G 2E1 , Canada
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Ferrari G, Balasubramanian P, Tubaldi E, Giovanniello F, Amabili M. Experiments on dynamic behaviour of a Dacron aortic graft in a mock circulatory loop. J Biomech 2019; 86:132-140. [PMID: 30799078 DOI: 10.1016/j.jbiomech.2019.01.053] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 12/23/2018] [Accepted: 01/30/2019] [Indexed: 11/27/2022]
Abstract
Woven Dacron grafts are currently used for the surgical treatment of aortic aneurysm and acute dissection, two otherwise fatal pathologies when aortic wall rupture occurs. While Dacron is chosen for aortic grafts because of characteristics such as biocompatibility and durability, few data are available about the dynamic response of Dacron prosthetic devices and about their side effects on the cardiovascular system. In this study, a Dacron graft was subjected to physiological flow conditions in a specifically-developed mock circulatory loop. Experiments were conducted at different physiological pulsation-per-minute rates. Results show that, in comparison to an aortic segment of the same length, the prosthesis is extremely stiffer circumferentially, thus limiting the dynamical radial expansion responsible for the Windkessel effect in human arteries. The prosthesis is instead excessively compliant in the axial direction and develops preferentially bending oscillations. This very different dynamic behaviour with respect to the human aorta can alter cardiovascular pressure and flow dynamics resulting in long-term implant complications.
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Affiliation(s)
- Giovanni Ferrari
- Dept. of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke St. W, Montreal H3A 0C3, Quebec, Canada
| | - Prabakaran Balasubramanian
- Dept. of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke St. W, Montreal H3A 0C3, Quebec, Canada
| | - Eleonora Tubaldi
- Department of Aerospace and Mechanical Engineering, University of Arizona, 1130 N. Mountain Ave., Tucson AZ 85721, USA
| | - Francesco Giovanniello
- Dept. of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke St. W, Montreal H3A 0C3, Quebec, Canada
| | - Marco Amabili
- Dept. of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke St. W, Montreal H3A 0C3, Quebec, Canada.
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Pavy C, Michielon G, Robertus JL, Lacour-Gayet F, Ghez O. Initial 2-year results of CardioCel® patch implantation in children. Interact Cardiovasc Thorac Surg 2019; 26:448-453. [PMID: 29069409 DOI: 10.1093/icvts/ivx295] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 08/03/2017] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES We present the initial 2-year results of CardioCel® patch (Admedus Regen Pty Ltd, Perth, WA, Australia) implantation in paediatric patients with congenital heart diseases. METHODS This was a single-centre retrospective study with prospectively collected data of all patients aged 18 years and under operated for congenital heart disease. The patch was introduced in 2014, with clinical practice committee approval and a special consent in case of an Ozaki procedure. Standard follow-up was performed with systematic clinical exams and echocardiograms. In case of reoperation or graft failure, the patch was removed and sent for a histological examination. RESULTS Between March 2014 and April 2016, 101 patients had surgical repair using a CardioCel patch. The mean age was 22 (±36.3) months, and the mean weight was 9.7 (±10.3) kg. No infections and no intraoperative implantation difficulties were associated with the patch. The median follow-up period was 212 (range 4-726) days. The overall 30-day postoperative mortality was 3.8% (n = 4), none of which were related to graft failure. Five children were reoperated because of graft failure, 4 of whom had the patch implanted for aortic and were aged less than 10 days. The indications for patch implantation in the aortic position were aortopulmonary window, truncus arteriosus, coarctation and aortic arch hypoplasia repair. The median time between the first and the second operation for graft failure was 245 (range 5-480) days. CONCLUSIONS Our experience shows that the patch is well tolerated in the septal, valvar and pulmonary artery positions. However, we experienced graft failures in infants in the aortic position.
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Affiliation(s)
- Carine Pavy
- Department of Cardiac Surgery, Royal Brompton Hospital, London, UK
| | - Guido Michielon
- Department of Cardiac Surgery, Royal Brompton Hospital, London, UK
| | | | | | - Olivier Ghez
- Department of Cardiac Surgery, Royal Brompton Hospital, London, UK
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28
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The influence of bileaflet prosthetic aortic valve orientation on the blood flow patterns in the ascending aorta. Med Eng Phys 2018; 60:61-69. [DOI: 10.1016/j.medengphy.2018.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 11/19/2022]
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Benayahu D, Sharabi M, Pomeraniec L, Awad L, Haj-Ali R, Benayahu Y. Unique Collagen Fibers for Biomedical Applications. Mar Drugs 2018; 16:md16040102. [PMID: 29570651 PMCID: PMC5923389 DOI: 10.3390/md16040102] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/09/2018] [Accepted: 03/17/2018] [Indexed: 12/14/2022] Open
Abstract
The challenge to develop grafts for tissue regeneration lies in the need to obtain a scaffold that will promote cell growth in order to form new tissue at a trauma-damaged site. Scaffolds also need to provide compatible mechanical properties that will support the new tissue and facilitate the desired physiological activity. Here, we used natural materials to develop a bio-composite made of unique collagen embedded in an alginate hydrogel material. The collagen fibers used to create the building blocks exhibited a unique hyper-elastic behavior similar to that of natural human tissue. The prominent mechanical properties, along with the support of cell adhesion affects cell shape and supports their proliferation, consequently facilitating the formation of a new tissue-like structure. The current study elaborates on these unique collagen fibers, focusing on their structure and biocompatibility, in an in vitro model. The findings suggest it as a highly appropriate material for biomedical applications. The promising in vitro results indicate that the distinctive collagen fibers could serve as a scaffold that can be adapted for tissue regeneration, in support of healing processes, along with maintaining tissue mechanical properties for the new regenerate tissue formation.
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Affiliation(s)
- Dafna Benayahu
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Mirit Sharabi
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Leslie Pomeraniec
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Lama Awad
- Department of Cell and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Rami Haj-Ali
- The Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Yehuda Benayahu
- School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
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Tubaldi E, Païdoussis MP, Amabili M. Nonlinear Dynamics of Dacron Aortic Prostheses Conveying Pulsatile Flow. J Biomech Eng 2018; 140:2672765. [DOI: 10.1115/1.4039284] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Indexed: 11/08/2022]
Abstract
This study addresses the dynamic response to pulsatile physiological blood flow and pressure of a woven Dacron graft currently used in thoracic aortic surgery. The model of the prosthesis assumes a cylindrical orthotropic shell described by means of nonlinear Novozhilov shell theory. The blood flow is modeled as Newtonian pulsatile flow, and unsteady viscous effects are included. Coupled fluid–structure Lagrange equations for open systems with wave propagation subject to pulsatile flow are applied. Physiological waveforms of blood pressure and velocity are approximated with the first eight harmonics of the corresponding Fourier series. Time responses of the prosthetic wall radial displacement are considered for two physiological conditions: at rest (60 bpm) and at high heart rate (180 bpm). While the response at 60 bpm reproduces the behavior of the pulsatile pressure, higher harmonics frequency contributions are observed at 180 bpm altering the shape of the time response. Frequency-responses show resonance peaks for heart rates between 130 bpm and 200 bpm due to higher harmonics of the pulsatile flow excitation. These resonant peaks correspond to unwanted high-frequency radial oscillations of the vessel wall that can compromise the long-term functioning of the prosthesis in case of significant physical activity. Thanks to this study, the dynamic response of Dacron prostheses to pulsatile flow can be understood as well as some possible complications in case of significant physical activity.
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Affiliation(s)
- Eleonora Tubaldi
- Mem. ASME Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, Canada e-mail:
| | - Michael P. Païdoussis
- Professor Fellow ASME Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, Canada e-mail:
| | - Marco Amabili
- Professor Fellow ASME Department of Mechanical Engineering, McGill University, Macdonald Engineering Building, 817 Sherbrooke Street West, Montreal, QC H3A 0C3 Canada e-mail:
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Straka F, Schornik D, Masin J, Filova E, Mirejovsky T, Burdikova Z, Svindrych Z, Chlup H, Horny L, Daniel M, Machac J, Skibová J, Pirk J, Bacakova L. A human pericardium biopolymeric scaffold for autologous heart valve tissue engineering: cellular and extracellular matrix structure and biomechanical properties in comparison with a normal aortic heart valve. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2018; 29:599-634. [PMID: 29338582 DOI: 10.1080/09205063.2018.1429732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of our study was to compare the cellular and extracellular matrix (ECM) structure and the biomechanical properties of human pericardium (HP) with the normal human aortic heart valve (NAV). HP tissues (from 12 patients) and NAV samples (from 5 patients) were harvested during heart surgery. The main cells in HP were pericardial interstitial cells, which are fibroblast-like cells of mesenchymal origin similar to the valvular interstitial cells in NAV tissue. The ECM of HP had a statistically significantly (p < 0.001) higher collagen I content, a lower collagen III and elastin content, and a similar glycosaminoglycans (GAGs) content, in comparison with the NAV, as measured by ECM integrated density. However, the relative thickness of the main load-bearing structures of the two tissues, the dense part of fibrous HP (49 ± 2%) and the lamina fibrosa of NAV (47 ± 4%), was similar. In both tissues, the secant elastic modulus (Es) was significantly lower in the transversal direction (p < 0.05) than in the longitudinal direction. This proved that both tissues were anisotropic. No statistically significant differences in UTS (ultimate tensile strength) values and in calculated bending stiffness values in the longitudinal or transversal direction were found between HP and NAV. Our study confirms that HP has an advantageous ECM biopolymeric structure and has the biomechanical properties required for a tissue from which an autologous heart valve replacement may be constructed.
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Affiliation(s)
- Frantisek Straka
- a Cardiology Centre and Cardiovascular Surgery Department , Institute for Clinical and Experimental Medicine , Prague , Czech Republic.,b Department of Biomaterials and Tissue Engineering , Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - David Schornik
- b Department of Biomaterials and Tissue Engineering , Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Jaroslav Masin
- a Cardiology Centre and Cardiovascular Surgery Department , Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Elena Filova
- b Department of Biomaterials and Tissue Engineering , Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Tomas Mirejovsky
- c Clinical and Transplant Pathology Department, Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Zuzana Burdikova
- d Department of Cell Biology, School of Medicine , University of Virginia , Charlottesville , VA , USA
| | - Zdenek Svindrych
- e Department of Biology, W. M, Keck Center for Cellular Imaging , University of Virginia , Charlottesville , VA , USA
| | - Hynek Chlup
- f Faculty of Mechanical Engineering, Department of Mechanics, Biomechanics and Mechatronics , Czech Technical University in Prague , Prague , Czech Republic
| | - Lukas Horny
- f Faculty of Mechanical Engineering, Department of Mechanics, Biomechanics and Mechatronics , Czech Technical University in Prague , Prague , Czech Republic
| | - Matej Daniel
- f Faculty of Mechanical Engineering, Department of Mechanics, Biomechanics and Mechatronics , Czech Technical University in Prague , Prague , Czech Republic
| | - Jiri Machac
- g Institute of Botany CAS, Academy of Sciences of the Czech Republic , Pruhonice , Czech Republic
| | - Jelena Skibová
- h Department of Medical Statistics , Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Jan Pirk
- a Cardiology Centre and Cardiovascular Surgery Department , Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | - Lucie Bacakova
- b Department of Biomaterials and Tissue Engineering , Institute of Physiology, Academy of Sciences of the Czech Republic , Prague , Czech Republic
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Liberski A, Ayad N, Wojciechowska D, Kot R, Vo DM, Aibibu D, Hoffmann G, Cherif C, Grobelny-Mayer K, Snycerski M, Goldmann H. Weaving for heart valve tissue engineering. Biotechnol Adv 2017; 35:633-656. [DOI: 10.1016/j.biotechadv.2017.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 10/19/2022]
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Elomaa L, Yang YP. Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs. TISSUE ENGINEERING. PART B, REVIEWS 2017; 23:436-450. [PMID: 27981886 PMCID: PMC5652978 DOI: 10.1089/ten.teb.2016.0348] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022]
Abstract
There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.
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Affiliation(s)
- Laura Elomaa
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California
| | - Yunzhi Peter Yang
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, California
- Department of Materials Science and Engineering, Stanford University School of Engineering, Stanford, California
- Department of Bioengineering, Stanford University School of Engineering, Stanford, California
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Mohammadi H, Cartier R, Mongrain R. Fiber-reinforced computational model of the aortic root incorporating thoracic aorta and coronary structures. Biomech Model Mechanobiol 2017; 17:263-283. [PMID: 28929388 DOI: 10.1007/s10237-017-0959-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 08/31/2017] [Indexed: 01/03/2023]
Abstract
Cardiovascular diseases are still the leading causes of death in the developed world. The decline in the mortality associated with circulatory system diseases is accredited to development of new diagnostic and prognostic tools. It is well known that there is an inter relationship between the aortic valve impairment and pathologies of the aorta and coronary vessels. However, due to the limitations of the current tools, the possible link is not fully elucidated. Following our previous model of the aortic root including the coronaries, in this study, we have further developed the global aspect of the model by incorporating the anatomical structure of the thoracic aorta. This model is different from all the previous studies in the sense that inclusion of the coronary structures and thoracic aorta into the natural aortic valve introduces the notion of globality into the model enabling us to explore the possible link between the regional pathologies. The developed model was first validated using the available data in the literature under physiological conditions. Then, to provide a support for the possible association between the localized cardiovascular pathologies and global variations in hemodynamic conditions, we simulated the model for two pathological conditions including moderate and severe aortic valve stenoses. The findings revealed that malformations of the aortic valve are associated with development of low wall shear stress regions and helical blood flow in thoracic aorta that are considered major contributors to aortic pathologies.
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Affiliation(s)
- Hossein Mohammadi
- Mechanical Engineering Department, McGill University, Montreal, QC, H3A 0C3, Canada
| | - Raymond Cartier
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Rosaire Mongrain
- Mechanical Engineering Department, McGill University, Montreal, QC, H3A 0C3, Canada.
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada.
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Cervi E, Nodari F, Botteri E, Mazzeo G, Stefano B. Appearance and rapid evolution of thoraco-abdominal intramural hematoma after TEVAR. JRSM Cardiovasc Dis 2017; 6:2048004017710884. [PMID: 28616205 PMCID: PMC5461912 DOI: 10.1177/2048004017710884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/23/2017] [Accepted: 04/25/2017] [Indexed: 12/02/2022] Open
Abstract
Some studies consider the different physical properties of the stent graft when compared with the blood vessel on the basis of vascular lesions that may require further intervention. We present a case in which a patient developed an intramural hematoma at the distal landing of previous thoracic endovascular aortic repair (TEVAR) that required the relining with a flared prosthesis. During follow-up, we observed the appearance of more caudal hematoma. We decided to observe this lesion with close radiological controls. In order to prevent serious complication after the induction of TEVAR, accurate planning of the procedure is very important to study the impact of the prosthesis implanted in the cardiovascular system. In particular, oversize, radial forces and length of coverage have been taken into account. The adherence to follow-up is very important to precociously detect the lesions to avoid the onset of complication.
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Affiliation(s)
- Edoardo Cervi
- Vascular Surgery, Department of Clinical and Experimental Sciences, University of Brescia, Spedali Civili Hospital, Brescia, Italy
| | - Franco Nodari
- Vascular Surgery, Department of Clinical and Experimental Sciences, University of Brescia, Spedali Civili Hospital, Brescia, Italy
| | - Emanuele Botteri
- Vascular Surgery, Department of Clinical and Experimental Sciences, University of Brescia, Spedali Civili Hospital, Brescia, Italy
| | - Girolomina Mazzeo
- Vascular Surgery, Department of Clinical and Experimental Sciences, University of Brescia, Spedali Civili Hospital, Brescia, Italy
| | - Bonardelli Stefano
- Vascular Surgery, Department of Clinical and Experimental Sciences, University of Brescia, Spedali Civili Hospital, Brescia, Italy
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Oguz GN, Piskin S, Ermek E, Donmazov S, Altekin N, Arnaz A, Pekkan K. Increased Energy Loss Due to Twist and Offset Buckling of the Total Cavopulmonary Connection. J Med Device 2017. [DOI: 10.1115/1.4035981] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The hemodynamic energy loss through the surgically implanted conduits determines the postoperative cardiac output and exercise capacity following the palliative repair of single-ventricle congenital heart defects. In this study, the hemodynamics of severely deformed surgical pathways due to torsional deformation and anastomosis offset are investigated. We designed a mock-up total cavopulmonary connection (TCPC) circuit to replicate the mechanically failed inferior vena cava (IVC) anastomosis morphologies under physiological venous pressure (9, 12, 15 mmHg), in vitro, employing the commonly used conduit materials: Polytetrafluoroethylene (PTFE), Dacron, and porcine pericardium. The sensitivity of hemodynamic performance to torsional deformation for three different twist angles (0 deg, 30 deg, and 60 deg) and three different caval offsets (0 diameter (D), 0.5D, and 1D) are digitized in three dimensions and employed in computational fluid dynamic (CFD) simulations to determine the corresponding hydrodynamic efficiency levels. A total of 81 deformed conduit configurations are analyzed; the pressure drop values increased from 80 to 1070% with respect to the ideal uniform diameter IVC conduit flow. The investigated surgical materials resulted in significant variations in terms of flow separation and energy loss. For example, the porcine pericardium resulted in a pressure drop that was eight times greater than the Dacron conduit. Likewise, PTFE conduit resulted in a pressure drop that was three times greater than the Dacron conduit under the same venous pressure loading. If anastomosis twist and/or caval offset cannot be avoided intraoperatively due to the anatomy of the patient, alternative conduit materials with high structural stiffness and less influence on hemodynamics can be considered.
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Affiliation(s)
- Gokce Nur Oguz
- Department of Mechanical Engineering, Koç University, Sarıyer, Istanbul 34450, Turkey
| | - Senol Piskin
- Department of Mechanical Engineering, Koç University, Sarıyer, Istanbul 34450, Turkey
| | - Erhan Ermek
- Department of Mechanical Engineering, Koç University, Sarıyer, Istanbul 34450, Turkey
| | - Samir Donmazov
- Department of Mechanical Engineering, Koç University, Sarıyer, Istanbul 34450, Turkey
| | - Naz Altekin
- Department of Mechanical Engineering, Koç University, Sarıyer, Istanbul 34450, Turkey
| | - Ahmet Arnaz
- Department of Cardiovascular Surgery, Acıbadem Bakırköy Hospital, Istanbul 34450, Turkey
| | - Kerem Pekkan
- Department of Mechanical Engineering, Koç University, Rumeli Feneri Campus, Sarıyer, Istanbul 34450, Turkey e-mail:
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Mohammadi H, Cartier R, Mongrain R. 3D physiological model of the aortic valve incorporating small coronary arteries. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e2829. [PMID: 27591390 DOI: 10.1002/cnm.2829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/04/2016] [Accepted: 08/26/2016] [Indexed: 06/06/2023]
Abstract
The diseases of the coronary arteries and the aortic root are still the leading causes of mortality and morbidity worldwide. In this study, a 3D global fluid-structure interaction of the aortic root with inclusion of anatomically inspired small coronary arteries using the finite element method is presented. This innovative model allows to study the impact and interaction of root biomechanics on coronary hemodynamics and brings a new understanding to small coronary vessels hemodynamics. For the first time, the velocity profiles and shear stresses are reported in distal coronary arteries as a result of the aortic flow conditions in a global fluid-structure interaction model.
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Affiliation(s)
- Hossein Mohammadi
- Mechanical Engineering Department, McGill University, Montreal, Quebec, H3A 0C3, Canada
| | - Raymond Cartier
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, Quebec, H1T 1C8, Canada
| | - Rosaire Mongrain
- Mechanical Engineering Department, McGill University, Montreal, Quebec, H3A 0C3, Canada
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, Quebec, H1T 1C8, Canada
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Buscemi S, Palumbo V, Maffongelli A, Fazzotta S, Palumbo F, Licciardi M, Fiorica C, Puleio R, Cassata G, Fiorello L, Buscemi G, lo Monte A. Electrospun PHEA-PLA/PCL Scaffold for Vascular Regeneration: A Preliminary in Vivo Evaluation. Transplant Proc 2017; 49:716-721. [DOI: 10.1016/j.transproceed.2017.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Alreshidan M, Shahmansouri N, Chung J, Lash V, Emmott A, Leask RL, Lachapelle K. Obtaining the biomechanical behavior of ascending aortic aneurysm via the use of novel speckle tracking echocardiography. J Thorac Cardiovasc Surg 2017; 153:781-788. [DOI: 10.1016/j.jtcvs.2016.11.056] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 10/11/2016] [Accepted: 11/04/2016] [Indexed: 12/19/2022]
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Mohammadi H, Cartier R, Mongrain R. The impact of the aortic valve impairment on the distant coronary arteries hemodynamics: a fluid-structure interaction study. Med Biol Eng Comput 2017; 55:1859-1872. [PMID: 28316038 DOI: 10.1007/s11517-017-1636-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 03/13/2017] [Indexed: 12/30/2022]
Abstract
Atherosclerosis is still the leading cause of death in the developed world. Although its initiation and progression is a complex multifactorial process, it is well known that blood flow-induced wall shear stress (WSS) is an important factor involved in early atherosclerotic plaque initiation. In recent clinical studies, it was established that the regional pathologies of the aortic valve can be involved in the formation of atherosclerotic plaques. However, the impact of hemodynamic effects is not yet fully elucidated for disease initiation and progression. In this study, our developed 3D global fluid-structure interaction model of the aortic root incorporating coronary arteries is used to investigate the possible interaction between coronary arteries and aortic valve pathologies. The coronary hemodynamics was examined and quantified for different degrees of aortic stenosis varying from nonexistent to severe. For the simulated healthy model, the calculated WSS varied between 0.41 and 1.34 Pa which is in the atheroprotective range. However, for moderate and severe aortic stenoses, wide regions of the coronary structures, especially the proximal sections around the first bifurcation, were exposed to lower values of WSS and therefore they were prone to atherosclerosis even in the case of healthy coronary arteries.
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Affiliation(s)
- Hossein Mohammadi
- Mechanical Engineering Department, McGill University, Montreal, QC, H3A 0C3, Canada
| | - Raymond Cartier
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada
| | - Rosaire Mongrain
- Mechanical Engineering Department, McGill University, Montreal, QC, H3A 0C3, Canada.
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, QC, H1T 1C8, Canada.
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Singh C, Wang X, Morsi Y, Wong CS. Importance of stent-graft design for aortic arch aneurysm repair. AIMS BIOENGINEERING 2017. [DOI: 10.3934/bioeng.2017.1.133] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Moulakakis KG, Kadoglou NP, Antonopoulos CN, Mylonas SN, Kakisis J, Papadakis I, Karakitsos P, Liapis CD. Changes in Arterial Stiffness and N-terminal pro-brain natriuretic peptide Levels after Endovascular Repair of Descending Thoracic Aorta. Ann Vasc Surg 2017; 38:220-226. [DOI: 10.1016/j.avsg.2016.04.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/21/2016] [Accepted: 04/10/2016] [Indexed: 11/15/2022]
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Evaluating ascending aortic aneurysm tissue toughness: Dependence on collagen and elastin contents. J Mech Behav Biomed Mater 2016; 64:262-71. [DOI: 10.1016/j.jmbbm.2016.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/16/2016] [Accepted: 08/02/2016] [Indexed: 11/23/2022]
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Investigation on the Regional Loss Factor and Its Anisotropy for Aortic Aneurysms. MATERIALS 2016; 9:ma9110867. [PMID: 28773988 PMCID: PMC5457275 DOI: 10.3390/ma9110867] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/25/2016] [Accepted: 10/12/2016] [Indexed: 01/26/2023]
Abstract
An aortic aneurysm is a lethal arterial disease that mainly occurs in the thoracic and abdominal regions of the aorta. Thoracic aortic aneurysms are prevalent in the root/ascending parts of the aorta and can lead to aortic rupture resulting in the sudden death of patients. Understanding the biomechanical and histopathological changes associated with ascending thoracic aortic aneurysms (ATAAs), this study investigates the mechanical properties of the aorta during strip-biaxial tensile cycles. The loss factor-defined as the ratio of dissipated energy to the energy absorbed during a tensile cycle-the incremental modulus, and their anisotropy indexes were compared with the media fiber compositions for aneurysmal (n = 26) and control (n = 4) human ascending aortas. The aneurysmal aortas were categorized into the aortas with bicuspid aortic valves (BAV) and tricuspid aortic valves (TAV). The strip-biaxial loss factor correlates well with the diameter of the aortas with BAV and TAV (for the axial direction, respectively, R² = 0.71, p = 0.0022 and R² = 0.54, p = 0.0096). The loss factor increases significantly with patients' age in the BAV group (for the axial direction: R² = 0.45, p = 0.0164). The loss factor is isotropic for all TAV quadrants, whereas it is on average only isotropic in the anterior and outer curvature regions of the BAV group. The results suggest that loss factor may be a useful surrogate measure to describe the histopathology of aneurysmal tissue and to demonstrate the differences between ATAAs with the BAV and TAV.
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Modelling and simulation of the mechanical response of a Dacron graft in the pressurization test and an end-to-end anastomosis. J Mech Behav Biomed Mater 2016; 61:36-44. [DOI: 10.1016/j.jmbbm.2016.01.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 11/22/2022]
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Nauta FJ, Conti M, Marconi S, Kamman AV, Alaimo G, Morganti S, Ferrara A, van Herwaarden JA, Moll FL, Auricchio F, Trimarchi S. An experimental investigation of the impact of thoracic endovascular aortic repair on longitudinal strain. Eur J Cardiothorac Surg 2016; 50:955-961. [DOI: 10.1093/ejcts/ezw180] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/26/2016] [Indexed: 11/13/2022] Open
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Emmott A, Garcia J, Chung J, Lachapelle K, El-Hamamsy I, Mongrain R, Cartier R, Leask RL. Biomechanics of the Ascending Thoracic Aorta: A Clinical Perspective on Engineering Data. Can J Cardiol 2016; 32:35-47. [DOI: 10.1016/j.cjca.2015.10.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/17/2015] [Accepted: 10/18/2015] [Indexed: 12/14/2022] Open
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Mechanical characterisation of Dacron graft: Experiments and numerical simulation. J Biomech 2016; 49:13-18. [DOI: 10.1016/j.jbiomech.2015.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 11/06/2015] [Accepted: 11/10/2015] [Indexed: 11/17/2022]
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Kubota H, Endo H, Noma M, Ishii H, Tsuchiya H, Yoshimoto A, Takahashi Y, Inaba Y, Nishino Y, Nunokawa M, Hosoi Y, Ikezoe T, Nemoto M, Makino Y, Nemoto Y, Matsukura M, Sugiyama M, Abe N, Takeuchi H, Nagao G, Kondo E, Yanagida O, Yoshino H, Sudo K. Xenopericardial roll graft replacement for infectious pseudoaneurysms and graft infections of the aorta. J Cardiothorac Surg 2015; 10:133. [PMID: 26506850 PMCID: PMC4624649 DOI: 10.1186/s13019-015-0343-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 10/26/2015] [Indexed: 11/29/2022] Open
Abstract
Background Which graft material is the optimal graft material for the treatment of infected aortic aneurysms and aortic graft infections is still a matter of controversy. Orthotopic aortic reconstruction with intraoperatively prepared xenopericardial roll grafts without omentopexy was performed as the “initial” operation to treat aortic infection or as a “rescue” operation to treat graft infection. Mid-term outcomes were evaluated. Methods Between 2009 and 2013, orthotopic xenopericardial roll graft replacement was performed to treat eight patients (male/female: 6/2; mean age: 69.5 [55–80] yr). Graft material: equine/bovine pericardium: 2/6; type of operation: initial 4/rescue 4; omentopexy 0. Additional operation: esophagectomy 2. Mean follow-up period: 2.6 ± 1.6 (1.1–5.1) years. Results Replacement: ascending 3, arch 1 (reconstruction of neck vessels with small xenopericardial roll grafts), descending 3, and thoracoabdominal 1. Pathogens: MRSA 2, MSSA 1, Candida 1, E. coli 1, oral bacillus 1, and culture negative 2. Postoperative local recurrence of infection: 0. Graft-related complications: stenosis 0, calcification 0, non-infectious pseudoaneurysm of anastomosis 2 (surgical repair: 1/TEVAR 1). In-hospital mortality: 2 (MOF: initial 1/rescue 1); Survival rate exclusive of in-hospital deaths (~3 y): 100 %, but one patient died of lung cancer (3.6 yr). Conclusions Because xenopericardial roll grafts are not composed of synthetic material, the replacement procedure is simpler and less invasive than the standard procedure. Based on the favorable results obtained, this procedure may have the possibility to serve as an option for the treatment of aortic infections and aortic graft infections not only as a “rescue” treatment but as an “initial” treatment as well. Electronic supplementary material The online version of this article (doi:10.1186/s13019-015-0343-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hiroshi Kubota
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
| | - Hidehito Endo
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Mio Noma
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Hikaru Ishii
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Hiroshi Tsuchiya
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Akihiro Yoshimoto
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Yu Takahashi
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Yusuke Inaba
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Yoshifumi Nishino
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Masao Nunokawa
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Yutaka Hosoi
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Tooru Ikezoe
- Department of Cardiovascular Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo, 181-8611, Japan
| | - Masaru Nemoto
- Department of Vascular Surgery, Tokyo University, Tokyo, Japan
| | | | - Yoko Nemoto
- Department of Vascular Surgery, Tokyo University, Tokyo, Japan
| | | | - Masanori Sugiyama
- Department of Gastroenterological Surgery, Kyorin University, Tokyo, Japan
| | - Nobutsugu Abe
- Department of Gastroenterological Surgery, Kyorin University, Tokyo, Japan
| | - Hirohisa Takeuchi
- Department of Gastroenterological Surgery, Kyorin University, Tokyo, Japan
| | - Gen Nagao
- Department of Gastroenterological Surgery, Kyorin University, Tokyo, Japan
| | - Eri Kondo
- Department of Gastroenterological Surgery, Kyorin University, Tokyo, Japan
| | - Osamu Yanagida
- Kosei General Hospital affiliated to Rissho Kosei-Kai, Tokyo, Japan
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Singh C, Wong CS, Wang X. Medical Textiles as Vascular Implants and Their Success to Mimic Natural Arteries. J Funct Biomater 2015; 6:500-25. [PMID: 26133386 PMCID: PMC4598668 DOI: 10.3390/jfb6030500] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 06/18/2015] [Accepted: 06/18/2015] [Indexed: 02/06/2023] Open
Abstract
Vascular implants belong to a specialised class of medical textiles. The basic purpose of a vascular implant (graft and stent) is to act as an artificial conduit or substitute for a diseased artery. However, the long-term healing function depends on its ability to mimic the mechanical and biological behaviour of the artery. This requires a thorough understanding of the structure and function of an artery, which can then be translated into a synthetic structure based on the capabilities of the manufacturing method utilised. Common textile manufacturing techniques, such as weaving, knitting, braiding, and electrospinning, are frequently used to design vascular implants for research and commercial purposes for the past decades. However, the ability to match attributes of a vascular substitute to those of a native artery still remains a challenge. The synthetic implants have been found to cause disturbance in biological, biomechanical, and hemodynamic parameters at the implant site, which has been widely attributed to their structural design. In this work, we reviewed the design aspect of textile vascular implants and compared them to the structure of a natural artery as a basis for assessing the level of success as an implant. The outcome of this work is expected to encourage future design strategies for developing improved long lasting vascular implants.
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Affiliation(s)
- Charanpreet Singh
- Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
| | - Cynthia S Wong
- Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
| | - Xungai Wang
- Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
- School of Textile Science and Engineering, Wuhan Textile University, Wuhan 430073, China.
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