1
|
Structural abnormalities after aortic root replacement with stentless xenograft. J Thorac Cardiovasc Surg 2023; 165:1285-1297.e6. [PMID: 34116854 DOI: 10.1016/j.jtcvs.2021.04.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/11/2021] [Accepted: 04/24/2021] [Indexed: 11/21/2022]
Abstract
OBJECTIVE In complex and high-risk aortic root disease, the porcine Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, Minn) is an important surgical treatment option. We aimed to determine prevalence and clinical effect of structural and functional abnormalities after full-root Freestyle implantation. METHODS Our cross-sectional 2-center study combined with clinical follow-up included 253 patients with full-root Freestyle bioprostheses implanted from 1999 to 2017. Patients underwent transthoracic echocardiography (TTE) and contrast-enhanced, electrocardiogram-gated 4-dimensional cardiac computed tomography (4DCT) at median age 70 (interquartile range, 62-75) years. After 4DCT, clinical follow-up continued throughout 2018. Median follow-up was 3.3 years before 4DCT and 1.4 years after. RESULTS We identified abnormalities in 46% of patients, including pseudoaneurysms (n = 32; 13%), moderate or severe coronary ostial stenosis (n = 54; 21%), and moderate-severe leaflet thickening or reduced leaflet motion (n = 51; 20%). TTE only identified 1 patient with pseudoaneurysm. After 4DCT, the unadjusted hazard ratio for surgical reintervention among patients with abnormal 4DCT was 4.2 (95% confidence interval, 1.2-15.3), in all, 10% required a reintervention. 4DCT abnormalities were associated with a statistically nonsignificant increased risk of death, stroke, or myocardial infarction (hazard ratio obtained using Cox proportional hazards regression analysis, 2.4; 95% confidence interval, 0.7-7.6). In all, 4.0% died, 3.6% had a myocardial infarction, and 2.0% had a stroke. CONCLUSIONS Structural and functional abnormalities of the aortic root are frequent after Freestyle implantation and TTE appears to be insufficient for follow-up. Abnormalities might be associated with increased risk of reintervention and potentially adverse clinical outcomes. Longer follow-up and larger study populations are needed to further clarify the clinical implications of abnormalities identified with 4DCT.
Collapse
|
2
|
Kong Y, Liu J, Jiang H, Song L, Kong D, Wang Z, Leng X. Immunogenicity assessment of swim bladder-derived biomaterials. Biomater Sci 2023; 11:2738-2749. [PMID: 36807688 DOI: 10.1039/d2bm01419j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Fish swim bladder-derived biomaterials are prospective cardiovascular materials due to anti-calcification, adequate mechanical properties, and good biocompatibility. However, their immunogenic safety profile, which primarily determines their feasibility as medical devices in clinical practice, remains unknown. Herein, the immunogenicity of glutaraldehyde crosslinked fish swim bladder (Bladder-GA) and un-crosslinked swim bladder (Bladder-UN) samples was examined using in vitro and in vivo assays according to ISO 10993-20. The in vitro splenocyte proliferation assay showed that cell growth was lower in the extract medium of Bladder-UN and Bladder-GA, compared to the LPS-or Con A-treated group. Similar results were obtained in in vivo assays. In the subcutaneous implantation model, the thymus coefficient, spleen coefficient and ratio of immune cell subtypes showed no significant difference between the bladder groups and the sham group. In terms of the humoral immune response, the total IgM concentration was lower in the Bladder-GA and Bladder-UN groups (988 ± 238 μg ml-1 and 1095 ± 296 μg ml-1, respectively) than that in the sham group (1329 ± 132 μg ml-1) at 7 days. The total IgG concentrations were 422 ± 78 μg ml-1 in Bladder-GA and 469 ± 172 μg ml-1 in Bladder-UN at 30 days, which were slightly higher than that in the sham group (276 ± 95 μg ml-1) but there was no significant difference compared with Bovine-GA (468 ± 172 μg ml-1), indicating that these materials did not elicit a strong humoral immune response. Systemic immune response-related cytokines and C-reactive protein were stable during implantation, while IL-4 levels increased with time. The classical foreign body response was not observed around all the implants, and the ratio of CD163+/iNOS macrophages in Bladder-GA and Bladder-UN was higher than that in the Bovine-GA group at the implanted site at 7 and 30 days. Finally, no organ toxicity was observed in any of the groups. Collectively, the swim bladder-derived material did not elicit significant aberrant immune responses in vivo, giving strong confidence for its application in tissue engineering or medical devices. Furthermore, more dedicated research on immunogenic safety assessment in large animal models is encouraged to facilitate the clinical practice of swim bladder-derived materials.
Collapse
Affiliation(s)
- Yuanyuan Kong
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Jing Liu
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Honghui Jiang
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | - Lili Song
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China. .,College of Life Sciences, Tiangong University, Tianjin 300387, China
| | - Deling Kong
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China. .,Key Laboratory of Bioactive Materials of Ministry of Education, State Key Laboratory of Medicinal Chemical Biology, College of Life Science, Nankai University, Tianjin 300071, China
| | - Zhihong Wang
- Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China.
| | | |
Collapse
|
3
|
Bozso SJ, Kang JJH, El-Andari R, Boe D, Hedtke H, Moon MC, Freed DH, Nagendran J, Nagendran J. Recellularized bovine pericardium with autologous mesenchymal stem cells reduces immune activation. Xenotransplantation 2022; 29:e12774. [PMID: 36098060 DOI: 10.1111/xen.12774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Current bioprosthetic heart valve replacement options are limited by structural valvular deterioration (SVD) due to an immune response to the xenogenic scaffold. Autologous mesenchymal stem cell (MSC) recellularization is a method of concealing xenogenic scaffolds, preventing recipient immune recognition of xenogenic tissue heart valves, and potentially leading to reduction in SVD incidence. The purpose of this study is to examine the effects of autologous MSC recellularized tissue on the immune response of human whole blood to bovine pericardium (BP). We hypothesized that autologous MSC recellularization of BP will result in reduced pro-inflammatory cytokine production equivalent to autologous human pericardium. METHODS Bone marrow, human pericardium, and whole blood were collected from adult patients undergoing elective cardiac surgery. Decellularized BP underwent recellularization with autologous MSCs, followed by co-incubation with autologous whole blood. Immunohistochemical, microscopic, and quantitative immune analysis approaches were used. RESULTS We demonstrated that native BP, exposed to human whole blood, results in significant TNF-α and IL1β production. When decellularized BP is recellularized with autologous MSCs and exposed to whole blood, there is a significant reduction in TNF-α and IL1β production. Importantly, recellularized BP exposed to whole blood had similar production of TNF-α and IL1β when compared to autologous human pericardium exposed to human whole blood. CONCLUSION Our results suggest that preventing initial immune activation with autologous MSC recellularization may be an effective approach to decrease the recipient immune response, preventing recipient immune recognition of xenogeneic tissue engineered heart valves, and potentially leading to reduction in SVD incidence.
Collapse
Affiliation(s)
- Sabin J Bozso
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Jimmy J H Kang
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Ryaan El-Andari
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Dana Boe
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Hannah Hedtke
- Faculty of Graduate Studies and Research, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Michael C Moon
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Darren H Freed
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Jayan Nagendran
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Jeevan Nagendran
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
4
|
Butany J, Schoen FJ. Cardiac valve replacement and related interventions. Cardiovasc Pathol 2022. [DOI: 10.1016/b978-0-12-822224-9.00010-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
5
|
Bozso SJ, El-Andari R, Al-Adra D, Moon MC, Freed DH, Nagendran J, Nagendran J. A review of the immune response stimulated by xenogenic tissue heart valves. Scand J Immunol 2021; 93:e13018. [PMID: 33372305 DOI: 10.1111/sji.13018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/30/2020] [Accepted: 12/26/2020] [Indexed: 12/23/2022]
Abstract
Valvular heart disease continues to afflict millions of people around the world. In many cases, the only corrective treatment for valvular heart disease is valve replacement. Valve replacement options are currently limited, and the most common construct utilized are xenogenic tissue heart valves. The main limitation with the use of this valve type is the development of valvular deterioration. Valve deterioration results in intrinsic permanent changes in the valve structure, often leading to hemodynamic compromise and clinical symptoms of valve re-stenosis. A significant amount of research has been performed regarding the incidence of valve deterioration and determination of significant risk factors for its development. As a result, many believe that the underlying driver of valve deterioration is a chronic immune-mediated rejection process of the foreign xenogenic-derived tissue. The underlying mechanisms of how this occurs are an area of ongoing research and active debate. In this review, we provide an overview of the important components of the immune system and how they respond to xenografts. A review of the proposed mechanisms of xenogenic heart valve deterioration is provided including the immune response to xenografts. Finally, we discuss the role of strategies to combat valve degeneration such as preservation protocols, epitope modification and decellularization.
Collapse
Affiliation(s)
- Sabin J Bozso
- Department of Surgery, Division of Cardiac Surgery, University of Alberta, Edmonton, AB, Canada
| | - Ryaan El-Andari
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - David Al-Adra
- Department of Surgery, Division of Transplantation, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Michael C Moon
- Department of Surgery, Division of Cardiac Surgery, University of Alberta, Edmonton, AB, Canada
| | - Darren H Freed
- Department of Surgery, Division of Cardiac Surgery, University of Alberta, Edmonton, AB, Canada
| | - Jayan Nagendran
- Department of Surgery, Division of Cardiac Surgery, University of Alberta, Edmonton, AB, Canada
| | - Jeevan Nagendran
- Department of Surgery, Division of Cardiac Surgery, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
6
|
Bozso SJ, Kang JJH, Basu R, Adam B, Dyck JRB, Oudit GY, Moon MC, Freed DH, Nagendran J, Nagendran J. Structural Valve Deterioration Is Linked to Increased Immune Infiltrate and Chemokine Expression. J Cardiovasc Transl Res 2020; 14:503-512. [PMID: 33089488 DOI: 10.1007/s12265-020-10080-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/15/2020] [Indexed: 01/04/2023]
Abstract
We aim to investigate whether structural valve deterioration (SVD) of bioprosthetic xenogenic tissue heart valves (XTHVs) is associated with increased immune cell infiltration and whether co-expression of several chemokines correlates with this increase in immune infiltrate. Explanted XTHVs from patients undergoing redo valve replacement for SVD were obtained. Immunohistochemical, microscopic, and gene expression analysis approaches were used. XTHVs (n = 37) were obtained from 32 patients (mean 67.7 years) after a mean time of 11.6 years post-implantation. Significantly increased immune cellular infiltration was observed in the explanted SVD valves for all immune cell types examined, including T cells, macrophages, B cells, neutrophils, and plasma cells, compared to non-SVD controls. Furthermore, a significantly increased chemokine gradient in explanted SVD valves accompanied immune cell infiltration. These data suggest the development of SVD is associated with a significantly increased burden of immune cellular infiltrate correlated to the induction of a chemokine gradient around the XHTV, representing chronic immune rejection.Graphical abstract Proposed interaction between innate and adaptive immunity leading to the development of structural valve deterioration in xenogenic tissue heart valves.
Collapse
Affiliation(s)
- Sabin J Bozso
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Jimmy J H Kang
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Ratnadeep Basu
- Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Benjamin Adam
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Jason R B Dyck
- Cardiovascular Research Centre, Division of Pediatrics, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Gavin Y Oudit
- Cardiovascular Research Centre, Division of Cardiology, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Michael C Moon
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Darren H Freed
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Jayan Nagendran
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - Jeevan Nagendran
- Division of Cardiac Surgery, Department of Surgery, University of Alberta, Edmonton, AB, T6G 2R3, Canada.
| |
Collapse
|
7
|
Bekke K, Dagnegård H, Sigvardsen PE, Smerup M. Myocardial ischaemia caused by bilateral coronary ostial stenosis from pseudointimal membranes in a full root freestyle valve: a case report. EUROPEAN HEART JOURNAL-CASE REPORTS 2020; 4:1-8. [PMID: 33426448 PMCID: PMC7780465 DOI: 10.1093/ehjcr/ytaa136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/11/2019] [Accepted: 04/30/2020] [Indexed: 11/15/2022]
Abstract
Background Coronary artery ostial stenosis is a rare but well-known complication to aortic root replacement. The occurrence of this complication in patients with the Medtronic Freestyle bioprosthesis is poorly described. We report a case of late bilateral coronary ostial stenosis due to pseudointimal membranes within a Medtronic Freestyle bioprosthesis, resulting in acute coronary syndrome. Case summary In 2013, a 43-year-old male patient received a Medtronic Freestyle bioprosthesis as a full aortic root implantation due to endocarditis with root abscess. Preoperative coronary angiography was normal. The patient, who had no previous symptoms of coronary ischaemia, presented with severe chest pain and acute coronary syndrome in 2017. Coronary angiography and electrocardiogram-gated contrast-enhanced cardiac computed tomography showed bilateral coronary ostial stenosis. The patient was successfully treated with coronary artery bypass grafting. Intraoperative inspection revealed pseudointimal membranes covering the coronary ostia. Histology showed fibro-intimal thickening with areas of inflamed granulation tissue. Discussion Bilateral coronary ostial stenosis is a severe, potentially life-threatening condition, and a possible complication to implantation of the Medtronic Freestyle bioprosthesis as a full root. The phenomenon may occur late and should be distinguished from arteriosclerotic coronary artery disease.
Collapse
Affiliation(s)
- Kirstine Bekke
- Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| | - Hanna Dagnegård
- Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| | - Per E Sigvardsen
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 20, Room 33.5.18-21, DK-2200 Copenhagen N, Denmark
| | - Morten Smerup
- Department of Cardiothoracic Surgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark
| |
Collapse
|
8
|
Takaya H, Masuda S, Naganuma M, Yoshioka I, Takahashi G, Akiyama M, Adachi O, Kumagai K, Sugita S, Saiki Y. Morphometrical and biomechanical analyses of a stentless bioprosthetic valve: an implication to avoid potential primary tissue failure. Gen Thorac Cardiovasc Surg 2018; 66:523-528. [PMID: 29956049 DOI: 10.1007/s11748-018-0959-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 06/15/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES Stentless bioprosthetic valves provide hemodynamic advantages over stented valves as well as excellent durability. However, some primary tissue failures in bioprostheses have been reported. This study was conducted to evaluate the morphometrical and biomechanical properties of the stentless Medtronic Freestyle™ aortic root bioprosthesis, to identify any arising problem areas, and to speculate on a potential solution. METHODS The three-dimensional heterogeneity of the stentless bioprosthesis wall was investigated using computed tomography. The ascending aorta and the right, left, and non-coronary sinuses of Valsalva were resected and examined by an indentation test to evaluate their biomechanical properties. RESULTS The non-coronary sinus of Valsalva was significantly thinner than the right sinus of Valsalva (p < 0.01). Young's modulus, calculated as an indicator of elasticity, was significantly greater at the non-coronary sinus of Valsalva (430.7 ± 374.2 kPa) than at either the left (190.6 ± 70.6 kPa, p < 0.01) or right sinuses of Valsalva (240.0 ± 56.5 kPa, p < 0.05). CONCLUSIONS Based on the morphometrical and biomechanical analyses of the stentless bioprosthesis, we demonstrated that there are differences in wall thickness and elasticity between each sinus of Valsalva. These differences suggest that the non-coronary sinus of Valsalva is the most vulnerable and at greater risk of tissue failure. The exclusion of the non-coronary sinus of Valsalva may be beneficial to mitigate the long-term risks of tissue failure in the stentless bioprosthesis.
Collapse
Affiliation(s)
- Hiroki Takaya
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Shinya Masuda
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Masaaki Naganuma
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Ichiro Yoshioka
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Goro Takahashi
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Masatoshi Akiyama
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Osamu Adachi
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| | - Kiichiro Kumagai
- Research Division of Sciences for Aortic Disease, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Shukei Sugita
- Biomechanics Laboratory, Department of Mechanical Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan
| | - Yoshikatsu Saiki
- Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryocho, Aoba-ku, Sendai, Miyagi, 980-8575, Japan
| |
Collapse
|
9
|
McGregor C, Byrne G, Rahmani B, Chisari E, Kyriakopoulou K, Burriesci G. Physical equivalency of wild type and galactose α 1,3 galactose free porcine pericardium; a new source material for bioprosthetic heart valves. Acta Biomater 2016; 41:204-209. [PMID: 27268480 PMCID: PMC4982525 DOI: 10.1016/j.actbio.2016.06.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/03/2016] [Accepted: 06/03/2016] [Indexed: 11/26/2022]
Abstract
UNLABELLED Humans make high levels of antibody to carbohydrates with terminal galactose α 1,3 galactose (Gal) modifications. This Gal antigen is widely expressed in other mammals and is present on an array of current animal derived biomedical devices including bioprosthetic heart valves. There is growing interest in using Gal-free animal tissues from Gal knockout pigs (GTKO) as these tissues would not be affected by anti-Gal antibody mediated injury. In this study we compare the composition and biophysical characteristics of glutaraldehyde fixed porcine pericardium from standard and GTKO pigs. We show that with the exception of the Gal antigen which is only present in standard pig tissue both GTKO and standard pig tissue have the same general morphology and collagen content. Moreover uniaxial stress testing and suture retention testing indicate the tissues are equivalent in tensile strength. These studies indicate that genetic disruption of the α-galactosyltransferase (GGTA-1) which blocks synthesis of the Gal antigen has no significant impact on the structural integrity of porcine pericardium and suggest that this tissue could be directly substituted for standard pig pericardium in biomedical devices such as bioprosthetic heart valves. STATEMENT OF SIGNIFICANCE Surgical heart valve replacement is a proven life saving therapy to treat heart valve dysfunction due to birth defects, infection and the effects of aging. Bioprosthetic heart valves (BHV) made from glutaraldehyde fixed animal tissues are an effective durable therapy in older patients (>60years) but exhibit age-dependent structural valve degeneration (SVD) in younger patients (<60years). SVD is principally caused by BHV calcification. Immune injury contributes to age-dependent SVD through the interaction of galactose α 1,3 galactose (Gal) a dominant xenogeneic antigen present on commercial BHVs and universally abundant human anti-Gal antibody. This study measures the tissue equivalency between standard pig pericardium and Gal-free pericardium from genetically modified pigs as a first step towards making Gal-free BHVs.
Collapse
Affiliation(s)
| | - Guerard Byrne
- University College London, Institute of Cardiovascular Science, United Kingdom.
| | - Benyamin Rahmani
- University College London, Department of Mechanical Engineering, United Kingdom
| | - Elisa Chisari
- University College London, Institute of Cardiovascular Science, United Kingdom
| | | | - Gaetano Burriesci
- University College London, Department of Mechanical Engineering, United Kingdom
| |
Collapse
|
10
|
Takahashi H, Arif R, Kallenbach K, Tochtermann U, Karck M, Ruhparwar A. Surgical Treatment of Aortic Valve Endocarditis With Left Ventricular-Aortic Discontinuity. Ann Thorac Surg 2013; 96:72-6. [DOI: 10.1016/j.athoracsur.2013.03.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 01/13/2013] [Accepted: 03/28/2013] [Indexed: 10/26/2022]
|
11
|
VanderLaan PA, Padera RF, Schoen FJ. Practical Approach to the Evaluation of Prosthetic Mechanical and Tissue Replacement Heart Valves. Surg Pathol Clin 2012; 5:353-69. [PMID: 26838108 DOI: 10.1016/j.path.2012.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mechanical and bioprosthetic substitute heart valves have dramatically improved life expectancy and quality of life in patients with valvular heart disease. Complications of substitute heart valves are a relatively infrequent occurrence, often due to thrombosis, infection, or structural/mechanical failure. It is important to accurately identify and systematically evaluate prosthetic heart valves when encountered as surgical pathology specimens or in the autopsy setting.
Collapse
Affiliation(s)
- Paul A VanderLaan
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | | | | |
Collapse
|