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Copes F, Pien N, Van Vlierberghe S, Boccafoschi F, Mantovani D. Collagen-Based Tissue Engineering Strategies for Vascular Medicine. Front Bioeng Biotechnol 2019; 7:166. [PMID: 31355194 PMCID: PMC6639767 DOI: 10.3389/fbioe.2019.00166] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/24/2019] [Indexed: 12/21/2022] Open
Abstract
Cardiovascular diseases (CVDs) account for the 31% of total death per year, making them the first cause of death in the world. Atherosclerosis is at the root of the most life-threatening CVDs. Vascular bypass/replacement surgery is the primary therapy for patients with atherosclerosis. The use of polymeric grafts for this application is still burdened by high-rate failure, mostly caused by thrombosis and neointima hyperplasia at the implantation site. As a solution for these problems, the fast re-establishment of a functional endothelial cell (EC) layer has been proposed, representing a strategy of crucial importance to reduce these adverse outcomes. Implant modifications using molecules and growth factors with the aim of speeding up the re-endothelialization process has been proposed over the last years. Collagen, by virtue of several favorable properties, has been widely studied for its application in vascular graft enrichment, mainly as a coating for vascular graft luminal surface and as a drug delivery system for the release of pro-endothelialization factors. Collagen coatings provide receptor-ligand binding sites for ECs on the graft surface and, at the same time, act as biological sealants, effectively reducing graft porosity. The development of collagen-based drug delivery systems, in which small-molecule and protein-based drugs are immobilized within a collagen scaffold in order to control their release for biomedical applications, has been widely explored. These systems help in protecting the biological activity of the loaded molecules while slowing their diffusion from collagen scaffolds, providing optimal effects on the targeted vascular cells. Moreover, collagen-based vascular tissue engineering substitutes, despite not showing yet optimal mechanical properties for their use in the therapy, have shown a high potential as physiologically relevant models for the study of cardiovascular therapeutic drugs and diseases. In this review, the current state of the art about the use of collagen-based strategies, mainly as a coating material for the functionalization of vascular graft luminal surface, as a drug delivery system for the release of pro-endothelialization factors, and as physiologically relevant in vitro vascular models, and the future trend in this field of research will be presented and discussed.
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Affiliation(s)
- Francesco Copes
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair Tier I for the Innovation in Surgery, Department of Min-Met-Materials Engineering & Regenerative Medicine, CHU de Quebec Research Center, Laval University, Quebec City, QC, Canada
- Laboratory of Human Anatomy, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Nele Pien
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair Tier I for the Innovation in Surgery, Department of Min-Met-Materials Engineering & Regenerative Medicine, CHU de Quebec Research Center, Laval University, Quebec City, QC, Canada
- Polymer Chemistry & Biomaterials Group, Department of Organic and Macromolecular Chemistry, Centre of Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Sandra Van Vlierberghe
- Polymer Chemistry & Biomaterials Group, Department of Organic and Macromolecular Chemistry, Centre of Macromolecular Chemistry, Ghent University, Ghent, Belgium
| | - Francesca Boccafoschi
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair Tier I for the Innovation in Surgery, Department of Min-Met-Materials Engineering & Regenerative Medicine, CHU de Quebec Research Center, Laval University, Quebec City, QC, Canada
- Laboratory of Human Anatomy, Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Diego Mantovani
- Laboratory for Biomaterials and Bioengineering, Canada Research Chair Tier I for the Innovation in Surgery, Department of Min-Met-Materials Engineering & Regenerative Medicine, CHU de Quebec Research Center, Laval University, Quebec City, QC, Canada
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Salem AM. Right ventricle to pulmonary artery connection: Evolution and current alternatives. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.jescts.2016.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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3
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Late complications and pathological findings of the arterial switch operation. Cardiol Young 2014; 24:167-9. [PMID: 23388218 DOI: 10.1017/s1047951113000085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We describe aortic root dilatation, severe aortic regurgitation, and pulmonary artery stenosis that were accidentally diagnosed 23 years after the arterial switch operation for transposition of the great arteries in situs inversus. We successfully performed the modified Bentall procedure and pulmonary artery reconstruction. The pathology of the dilated aortic root revealed intimal atherosclerosis and linear necrosis of the tunica media, suggesting the vulnerability of the pulmonary artery to systemic pressure.
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Emani SM. Options for prosthetic pulmonary valve replacement. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2012; 15:34-37. [PMID: 22424506 DOI: 10.1053/j.pcsu.2012.01.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This article reviews current data on various prostheses utilized for pulmonary valve replacement. Durability data is reviewed and risk factors for deterioration are examined. Finally, the choice of prosthesis should be tailored to the specific clinical scenario based on existing data regarding durability and risk factors.
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Affiliation(s)
- Sitaram M Emani
- Children's Hospital Boston, Harvard Medical School, Boston, MA, USA.
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5
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Yuan SM, Mishaly D, Shinfeld A, Raanani E. Right ventricular outflow tract reconstruction: valved conduit of choice and clinical outcomes. J Cardiovasc Med (Hagerstown) 2008; 9:327-37. [DOI: 10.2459/jcm.0b013e32821626ce] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Karamlou T, Blackstone EH, Hawkins JA, Jacobs ML, Kanter KR, Brown JW, Mavroudis C, Caldarone CA, Williams WG, McCrindle BW. Can pulmonary conduit dysfunction and failure be reduced in infants and children less than age 2 years at initial implantation? J Thorac Cardiovasc Surg 2006; 132:829-38. [PMID: 17000294 DOI: 10.1016/j.jtcvs.2006.06.034] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 06/01/2006] [Accepted: 06/16/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVES We sought to examine risk factors for pulmonary conduit failure or dysfunction in infants less than age 2 years at initial implantation. METHODS From 2002 to 2005, 241 children at 17 institutions were discharged alive after initial pulmonary conduit insertion. Initial conduit type was pulmonary allograft in 37%, aortic allograft in 29%, bovine jugular venous valved conduit in 25%, porcine heterograft in 2%, and decellularized allograft in 7%. Parametric hazard analysis determined time-related prevalence and associated risk factors for pulmonary conduit intervention and explantation. Serial echocardiographic measurements after conduit implant were analyzed by mixed regression models. RESULTS There were 89 first conduit-related interventions after discharge and 37 initial conduit explants were performed. First conduit intervention occurred at a constant rate, with a prevalence of 58% at 3 years from initial implant. Pulmonary conduit explantation (30% at 3 years) was characterized by an early-rising risk, suggesting that catheter-based intervention effectively blunts this early initial risk. Common risk-factors for first conduit intervention and explantation were smaller conduit Z-score and younger age at initial conduit implant, and the presence of pulmonary arborization abnormalities or stenoses. Pulmonary conduit peak gradient and regurgitation progressed nonlinearly in all patients over time. Gradient progressed more rapidly in children with aortic allografts and when initial conduit Z-score was less than +1 or more than +3. Pulmonary conduit regurgitation also progressed more rapidly in children with initial conduit Z-score greater than +3 and in those without jugular venous valved conduits, especially aortic allografts. CONCLUSIONS Pulmonary conduit durability and hemodynamic function in patients undergoing initial conduit insertion at less than age 2 years can be improved by using pulmonary conduits with Z-scores between +1 and +3.
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Affiliation(s)
- Tara Karamlou
- Division of Cardiovascular Surgery and Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
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Tatebe S, Nagakura S, Boyle EM, Duncan BW. Right Ventricle to Pulmonary Artery Reconstruction Using a Valved Homograft. Circ J 2003; 67:906-12. [PMID: 14578595 DOI: 10.1253/circj.67.906] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although the valved homograft is widely used to establish a connection between the right ventricle (RV) and the pulmonary artery (PA), its durability remains controversial. In the present study, the data on 141 valved homograft implantations in 107 consecutive patients performed from January 1990 to June 2000 were analyzed. The mean follow-up period was 4.6 years (range, 0.2-9.4 years). The clinical data, including clinic records, operative notes, follow-up visits, and letters from referring physicians, were analyzed with particular reference to variables associated with early and late mortality, deterioration of the homograft, and risk factors for patient survival and homograft failure. Early death occurred in 7.5% (n=8) of the cases, and each of these patients died without leaving the hospital. Late death occurred in 2 patients, for whom the cause of death was suggested to be related to arrhythmia. Thirteen patients underwent catheter intervention (ie, balloon dilatation and/or stenting) and 8 of these did not require homograft replacement following catheterization. The overall survival rate at both 3 years and 5 years was 88.9+/-3.4%. Cumulative freedom from total homograft failure was 82.5+/-3.6% at 1 year; 61.6+/-5.0% at 3 years; and 42.4+/-6.2% at 5 years. In comparison with 2 criteria of homograft failure (ie, total homograft failure and homograft failure including catheter intervention), the incidence of freedom from homograft failure including catheter intervention was lower than that of total homograft failure, although the difference was not statistically significant. In the multivariate analysis, significant risk factors with respect to patient survival were homograft replacement and the use of expanded polytetrafluoroethylene (ePTFE); those judged to be significant with respect to homograft failure were total repair with first homograft implantation and diagnosis of truncus arteriosus. The valved homograft was thus considered an appropriate choice of conduit between the RV and the PA, and it provided excellent patient survival. However, this type of homograft did not provide a completely permanent solution for the repair of complex cardiac anomalies. Therefore, the use of ePTFE for homograft extensions should be avoided. Finally, the results suggest that catheter intervention plays an important role in the longevity of the implanted homograft.
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Affiliation(s)
- Shoh Tatebe
- Division of Cardiac Surgery, Department of Surgery, Children's Hospital and Regional Medical Center, Seattle, Washington, USA
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Allen BS, El-Zein C, Cuneo B, Cava JP, Barth MJ, Ilbawi MN. Pericardial tissue valves and Gore-Tex conduits as an alternative for right ventricular outflow tract replacement in children. Ann Thorac Surg 2002; 74:771-7. [PMID: 12238838 DOI: 10.1016/s0003-4975(02)03767-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND There is still no perfect conduit for reconstruction of the right ventricular outflow tract (RVOT) in children. Homografts are not always available in the appropriate size, and degenerate in a few years. This study evaluates the pericardial valve with Gore-Tex conduit as an alternative for RVOT construction. METHODS From January 1, 1993, to September 30, 1999, a pericardial tissue valve was inserted in all patients undergoing RVOT reconstruction or pulmonary valve replacement (PVR) who were large enough to accommodate a tissue valve. In patients without a native main pulmonary artery, a new technique was used to construct an RV-PA conduit out of a flat sheet of Gore-Tex, as Dacron frequently leads to stenosis. Data were collected by retrospective review, follow-up echocardiograms, and assessment by a single cardiologist. RESULTS There were 48 patients, 22 undergoing a PVR alone and 26 a RV-PA valved Gore-Tex conduit. Diagnosis included tetralogy of Fallot (n = 25); truncus arteriosis (n = 9); ventricular septal defect with PA (n = 5); DORV (n = 4); D-TGA with PS (n = 2); and 1 each IAA with sub AS, VSD with PI, and PS s/p Ross procedure. Patient age ranged from 3 to 33 years and 98% were reoperations. The valve sizes ranged from 19 to 33 mm and the median hospital length of stay was 4 days. There were 2 (4.2%) perioperative and 1 (2.1%) late deaths, none related to the valve or Gore-Tex conduit. At a follow-up of 15 to 86 months (mean 43 +/- 16 months), all remaining 45 patients are New York Heart Association class I, all valves are functional, and no patient has required valve or conduit replacement or revision; more importantly, echocardiogram revealed no significant valve or conduit stenosis (mean gradient 16 +/- 8 mm Hg) and no evidence of regurgitation or structural degeneration. CONCLUSIONS A pericardial tissue valve and Gore-Tex conduit provides a reliable alternative for RVOT reconstruction in pediatric patients. It is readily available, molds in the limited retrosternal space, and has outstanding intermediate results with no evidence of failure or deterioration up to 7 years after insertion.
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Affiliation(s)
- Bradley S Allen
- Division of Cardiovascular Surgery, Heart Institute for Children, Hope Children's Hospital, Oak Lawn, Illinois 60453, USA.
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Kneebone JM, Lupinetti FM. Procollagen synthesis by fresh and cryopreserved rat pulmonary valve grafts. J Thorac Cardiovasc Surg 2000; 120:596-603. [PMID: 10962424 DOI: 10.1067/mtc.2000.107681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Allograft valves are frequently used in the repair of congenital cardiac anomalies. The failure rate may differ depending on the type of allograft used. Previous studies have shown that rat aortic valve grafts exhibit synthesis of procollagen, suggesting a capacity for repair and regeneration after implantation. No studies of pulmonary valve grafts in the heterotopic rat implant model have thus far been reported. This study was designed to investigate whether pulmonary valve grafts maintain in vivo viability, as demonstrated by procollagen synthesis, and whether cryopreservation, histocompatibility, or both affect this property. METHODS Cryopreserved and fresh rat pulmonary valves were implanted into the abdominal aorta of syngeneic and allogeneic recipients. The grafts and native valves were excised 3 to 21 days after implantation. Valves were sectioned and immunohistochemically stained for procollagen. Computerized morphometry was used to calculate changes in intima, media, and adventitia as a percentage of cross-sectional area of the graft. Procollagen content was graded by semiquantitative methods. RESULTS Pulmonary valve grafts had significantly greater collagen density in the intima and adventitia compared with native aortic and pulmonary tissues, but collagen density in the media was similar in all groups. The grafts demonstrated appreciably greater procollagen than the corresponding native valves. These findings were consistent in all grafts (ie, both fresh and cryopreserved, both syngeneic and allogeneic), irrespective of duration of implantation. CONCLUSIONS Procollagen synthesis occurs in pulmonary valve grafts early after implantation, indicating viability of these tissues. This model of pulmonary valve implantation may have wide applicability to questions of allograft biology.
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Affiliation(s)
- J M Kneebone
- Division of Cardiovascular Surgery, Department of Surgery, Children's Hospital and Regional Medical Center, and the University of Washington, Seattle, WA 98105, USA
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11
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Aeba R, Katogi T, Kawada S. Hemashield implantation in young patients with congenital cardiovascular lesions. Ann Thorac Surg 2000; 69:1920-4; discussion 1924-5. [PMID: 10892947 DOI: 10.1016/s0003-4975(00)01257-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND There is substantial controversy regarding the use of Hemashield in young patients. METHODS Twenty-one consecutive patients younger than 20 years of age with a variety of congenital cardiovascular lesions underwent surgical procedures using a Hemashield woven graft. Hemashield was used for reconstruction of the aortic wall (n = 16), ventricular septum (n = 10), and right ventricular free wall or pulmonary artery (n = 6). RESULTS A sterile inflammatory reaction was observed including high fever, increased white cell count, and elevated plasma C-reactive protein concentration for up to 4 weeks after implantation. Multivariable analysis identified the use of Hemashield in the right ventricular free wall or pulmonary artery as an incremental risk factor for elevation of plasma C-reactive protein concentration during the first 3 weeks after implantation (p = 0.002). There were no midterm complications including restenosis of the grafts in the right ventricular outflow tract. CONCLUSIONS Hemashield can be used in a variety of situations for reconstruction of congenital cardiovascular lesions in young patients. Impregnated collagen can cause a significant systemic inflammatory reaction for several weeks after implantation, especially when used in the low-pressure right heart.
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Affiliation(s)
- R Aeba
- Division of Cardiovascular Surgery, Keio University, Tokyo, Japan.
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12
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Backer CL, Mavroudis C. Invited commentary. Ann Thorac Surg 2000. [DOI: 10.1016/s0003-4975(00)01259-5] [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: 10/18/2022]
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Mercan S, Sezgin A, Gültekin B, Tokel K, Saygili A, Varan B, Aşlamaci S. Xenograft and homograft transplantation in cardiac surgery at Başkent University Hospital. Transplant Proc 2000; 32:594-5. [PMID: 10812127 DOI: 10.1016/s0041-1345(00)00905-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- S Mercan
- Faculty of Medicine, Departments of Cardiovascular Surgery and Pediatric Cardiology, Başkent University, Ankara, Turkey
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Chakfé N, Bizonne SC, Beaufigeau M, Urban E, Cardon A, Doillon C, Le Magnen JF, Durand B, Kretz JG. Impregnated polyester arterial prostheses: performance and prospects. Ann Vasc Surg 1999; 13:509-23. [PMID: 10466995 DOI: 10.1007/s100169900291] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Impregnated polyester arterial prostheses have gained wide acceptance by most vascular surgery teams, probably because these prostheses are easy to use, without any preclotting. We offer here a synthesis of the main studies that have appraised the experimental and clinical performance of these prostheses, and we delineate their major prospects.
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Affiliation(s)
- N Chakfé
- Groupe Européen de Recherche sur les Prothèses Appliquées à la Chirurgie Vasculaire, Strasbourg, France
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Mavroudis C, Backer CL, Kohr LM, Deal BJ, Stinios J, Muster AJ, Wax DF. Bidirectional Glenn shunt in association with congenital heart repairs: the 1(1/2) ventricular repair. Ann Thorac Surg 1999; 68:976-81; discussion 982. [PMID: 10509994 DOI: 10.1016/s0003-4975(99)00562-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The bidirectional Glenn shunt has been used to incorporate a smaller tripartite ventricle into the circulation and create pulsatile pulmonary artery flow. We reviewed our operative experience and assessed hemodynamics of the bidirectional Glenn shunt in 1(1/2) ventricular repair or in conjunction with other repairs of congenital heart defects. METHODS Between 1992 and 1998, 15 patients (mean age, 8.1+/-7.9 years) had bidirectional Glenn shunt in association with repair of congenital heart defects. Eighty-seven percent had at least one previous operation. All patients had simultaneous or previous intracardiac repair and had bidirectional Glenn shunt to volume unload the small right ventricle (group A, n = 7), to unload the poorly functioning right ventricle (group B, n = 2), to redirect superior vena cava-pulmonary venous atrial connection to treat cyanosis (group C, n = 2), or to unload the pulmonary left ventricle for residual intracavitary hypertension in patients with L-transposition of the great arteries, ventricular septal defect, and pulmonary stenosis (group D, n = 4). Intraoperative hemodynamic assessment was done in 2 patients in group A by selective use of inflow occlusion and flow probes. RESULTS All patients survived. Four patients had successful, concurrent arrhythmia circuit cryoablation for Wolf-Parkinson-White syndrome (n = 1) or atrial reentry tachycardia (n = 3). Superior and inferior vena caval flow averaged 36% and 64% of cardiac output, respectively. Postoperative superior vena caval pressure (n = 13) was 13.7+/-4.0 mm Hg with pulmonary arterial flow pattern contributed by the ventricle in systole (pulsatile) and the superior vena cava in diastole (laminar). CONCLUSIONS The bidirectional Glenn shunt is an effective adjunct to congenital heart repair to treat pulmonary ventricular pressure-volume problems and anomalous superior vena caval to left atrial connections.
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Affiliation(s)
- C Mavroudis
- Division of Cardiovascular Surgery, Children's Memorial Hospital, Chicago, Illinois 60614, USA.
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Marois Y, Zhang Z, Vert M, Beaulieu L, Lenz RW, Guidoin R. In vivo biocompatibility and degradation studies of polyhydroxyoctanoate in the rat: a new sealant for the polyester arterial prosthesis. TISSUE ENGINEERING 1999; 5:369-86. [PMID: 10477858 DOI: 10.1089/ten.1999.5.369] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The present study examined the biocompatibility and degradation properties of poly (beta-hydroxy octanoate) (PHO) as an impregnation substrate on arterial prostheses. PHO-impregnated polyester grafts sterilized by ethylene oxide (EO) or gamma (gamma) radiation, and polyester Dacron(R) prostheses impregnated with fluoropolymer, gelatin, or albumin were implanted subcutaneously in rats for periods ranging from 2 to 180 days. The biocompatibility was assessed by quantifying the alkaline and acid phosphatase secretion while performing histological studies at the tissue/prosthesis interface. The degradation was determined by chemical analysis of the EO and gamma-sterilized PHO after implantation using differential scanning calorimetry (DSC), wide angle x-ray diffraction (WAXD), and size exclusion chromatography (SEC). Alkaline phosphatase activity by the sterilized PHO and by the gelatin and albumin grafts was significantly elevated early after implantation in contrast to that of the Dacron and fluoropolymer grafts that occurred later, at 7 and 5 days, respectively The peak of acid phosphatase activity for all of the grafts occurred between 5 and 10 days postimplantation, with the gamma-sterilized PHO grafts recording the greatest activity. Histological study revealed that the tissue incorporation into the graft wall was earlier and more complete for the Dacron and fluoropolymer grafts after 6 months than for the gelatin and albumin grafts, because the latter induced important inflammatory reactions during the resorption of the cross-linked protein substrates. The EO and gamma-sterilized PHO grafts exhibited a similar healing sequence characterized by the development of a collagenous tissue surrounding the prostheses. However, no infiltration of tissue into the graft wall was observed after 6 months, mainly because of the presence of the PHO. Degradation of the EO and gamma-sterilized PHO occurred preferentially by a hydrolytic mechanism as shown by a 30% molecular weight decrease after 6 months. In conclusion, PHO showed good biocompatibility in terms of enzyme activity and tissue reaction. Degradation was a slow, in vivo process controlled primarily by a random hydrolytic reaction and by a local enzymatic attack by macrophages and giant cells.
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Affiliation(s)
- Y Marois
- CRBA-URA CNRS 1465, Faculté de pharmacie, Université de Montpellier I, Montpellier, France
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Marois Y, Guidoin R, Deng X, King MW, Martin L, Roy R. The Dialine II graft: a new collagen-impregnated warp-knitted polyester arterial prosthesis. Ann Vasc Surg 1997; 11:133-40. [PMID: 9181767 DOI: 10.1007/s100169900023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Dialine graft, a new prototype of knitted vascular prosthesis that uses a different brand of polyester fibers as an alternative to Dacron fibers, has been shown to offer excellent in vitro physical performance and in vivo healing. Although it still requires preclotting, the Dialine prosthesis was made impervious by impregnation of bovine type I collagen cross-linked with vapors of formalin. The purpose of the present investigation was to compare the in vitro physical characteristics of the Dialine II graft with those of the collagen-impregnated Hemashield graft. In addition, we studied the healing performance as a thoracoabdominal bypass in dogs for prescheduled periods of implantation ranging from 4 hours to 6 months. In vitro, the bursting strength, resistance to dilatation, and suture retention strength properties of the Dialine II prosthesis were all shown to exceed those of the Hemashield control graft. In the first weeks after implantation, the Dialine II grafts induced a discrete inflammatory response, as shown by the constant leukocyte counts observed both before implantation and when the animals were killed, as well as by the histologic observation of a few inflammatory cells in contact with the collagen. Consequently, the Dialine II grafts showed a slow rate of bioresorption of cross-linked collagen. At 1 month, a thin internal collagenous capsule was present at both anastomoses, laying over the original collagen coating. At 3 and 6 months, areas of thrombotic deposits and endothelialized areas were observed on the luminal surface. Because results of early clinical trials have been highly satisfactory, this prosthesis may be recommended for use without restriction as a medium- and large-diameter blood conduit.
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Affiliation(s)
- Y Marois
- Department of Surgery, Laval University, Quebec City, Quebec, Canada
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Lupinetti FM, Kneebone JM, Rekhter MD, Brockbank KG, Gordon D. Procollagen production in fresh and cryopreserved aortic valve grafts. J Thorac Cardiovasc Surg 1997; 113:102-7. [PMID: 9011678 DOI: 10.1016/s0022-5223(97)70404-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Long-term durability of aortic valve allografts may be enhanced by cellular capacities for regeneration and repair. To evaluate aortic valve graft production of an important structural protein, rat aortic roots were implanted heterotopically into the abdominal aorta of recipient rats. Grafts were either syngeneic or strongly allogeneic, were implanted either fresh or after cryopreservation, and were left in place 2 to 21 days after implantation. A total of 80 aortic valve grafts and the corresponding native aortic valves were examined. The grafts were retrieved and immunocytochemically stained for the presence of procollagen, a precursor to collagen. Regardless of histocompatibility or preservation, grafts exhibited consistent procollagen presence that equaled or exceeded that seen in the corresponding native valves. Positive procollagen staining was predominantly in the aortic wall. The most prominent staining was near the hinge point of the valve leaflets, with no staining in the free portion of the leaflets. Staining with alpha-actin demonstrated vascular smooth muscle in sites remote from the areas positive for procollagen, which suggests that vascular smooth muscle was not responsible for the procollagen production. These findings indicate that cryopreservation is compatible with persistent fibroblast viability and in vivo protein synthesis by both syngeneic and allogeneic aortic valve grafts.
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Affiliation(s)
- F M Lupinetti
- Department of Surgery, University of Washington, Seattle 98105, USA
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Molina JE, Edwards JE, Bianco RW, Clack RW, Lang G, Molina JR. Composite and plain tubular synthetic graft conduits in right ventricle-pulmonary artery position: fate in growing lambs. J Thorac Cardiovasc Surg 1995; 110:427-35. [PMID: 7637361 DOI: 10.1016/s0022-5223(95)70239-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Our goal was to identify the most appropriate material for right ventricle-pulmonary artery conduits in growing animals. We used 100 lambs that were 3 to 4 weeks old (mean weight 11.7 kg). Follow-up was up to 24 months. Group I received plain tubular conduits: (1) Dacron knitted fabric, (2) collagen-coated knitted fabric, (3) Milliknit and Microknit material, (4) woven Dacron fabric, (5) three-dimensional Dacron fabric (crossweave 500 and 800), or (6) polytetrafluoroethylene. Group II received either a (1) woven Dacron fabric conduit with a built-in tissue valve or (2) polytetrafluoroethylene graft with a built-in St. Jude Medical valve. We did angiograms and catheterizations every 3 to 6 months and killed the lambs at 6, 12, 18, or 24 months. Tubular Dacron fabric woven or knitted grafts, regardless of matrix, pore size, thickness, or coating, caused formation of a thick acellular pseudointima buildup, which led to progressive obstruction starting as early as 3 months. Polytetrafluoroethylene grafts in groups I and II showed the formation of thin inner and outer capsules (0.5 mm) and none developed obstruction despite wall calcification. Conduits of woven Dacron fabric with a built-in tissue valve degenerated rapidly, leading to calcification thrombosis and obstruction within 3 months; no lamb survived 12 months. Polytetrafluoroethylene conduits with a St. Jude Medical valve in lambs receiving anticoagulants remained free of obstruction and continued to function well. It appears that synthetic conduits of polytetrafluoroethylene perform well in either of the situations here tested and may be the best choice at present.
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Affiliation(s)
- J E Molina
- Department of Surgery, University of Minnesota, Minneapolis, USA
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Bando K, Danielson GK, Schaff HV, Mair DD, Julsrud PR, Puga FJ. Outcome of pulmonary and aortic homografts for right ventricular outflow tract reconstruction. J Thorac Cardiovasc Surg 1995; 109:509-17; discussion 517-8. [PMID: 7877312 DOI: 10.1016/s0022-5223(95)70282-2] [Citation(s) in RCA: 155] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
To determine late patient outcome and homograft durability, we reviewed 326 patients who received aortic (n = 230) or pulmonary (n = 118) cryopreserved homografts for right ventricular outflow reconstruction between January 1985 and October 1993. Patient survival, including operative mortality, 5 years after the operation was similar between the two groups (pulmonary homograft 86%, aortic homograft 80%; p = not significant by log-rank test). However, 5-year freedom from homograft failure was significantly better for pulmonary homografts (94% versus 70%, p < 0.01 by log-rank test). Late calcification was evaluated by chest roentgenography and echocardiography. Overall, 20% of aortic homografts became moderately or severely calcified compared with 4% of pulmonary homografts (p < 0.01). Twenty-six percent of aortic homografts in children 4 years old or younger had moderate or severe obstruction associated with calcification, whereas only 11% of aortic homografts in patients over 4 years of age had calcific obstruction (p < 0.01). No late deaths among patients receiving pulmonary homografts were related to graft failure; two late deaths in the aortic homograft group were homograft related. Risk factors for patient mortality and homograft failure (defined as either need for homograft replacement because of homograft failure or as homograft-related death) were identified by the Cox multivariate analysis. Aortic type of homograft was a significant risk factor for homograft failure (p < 0.0001), but type of homograft was not correlated with patient mortality. Age 4 years or younger was a significant risk factor for both mortality (p < 0.01) and homograft failure (p = 0.03) in aortic homograft recipients but not in pulmonary homograft recipients. These results indicate that both aortic and pulmonary homografts provided excellent intermediate-term patient survival after right ventricular outflow tract reconstruction, but pulmonary homografts are more durable than aortic homografts with less calcification and obstruction, especially among children 4 years old or younger.
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Affiliation(s)
- K Bando
- Division of Thoracic and Cardiovascular Surgery, Mayo Clinic, Rochester, Minn
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