Xenograft bioprosthetic heart valves: Past, present and future

Manji, Rizwan A.; Lee, Whayoung; Cooper, David K.C.

doi:10.1016/j.ijsu.2015.07.009

Cited by 139 publications

(121 citation statements)

References 37 publications

(34 reference statements)

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“…Biological valves still have poor long‐term durability due to calcification and mechanical failure. Bovine pericardial tissue and aortic porcine valves (stented or unstented) fixed with glutaraldehyde are used to construct heart valves in which the design characteristics are the main differences between heart valve manufacturers . So it is necessary to select a more appropriate tissue, mechanically and histologically, which can improve the long‐term durability of these valves.…”

Section: Introductionmentioning

confidence: 99%

Comparison of tensile properties of xenopericardium from three animal species and finite element analysis for bioprosthetic heart valve tissue

et al. 2019

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Bioprosthetic heart valves still have poor long‐term durability due to calcification and mechanical failure. The function and performance of bioprostheses is known to depend on the collagen architecture and mechanical behavior of the target tissue. So it is necessary to select an appropriate tissue for such prostheses. In this study, porcine, equine, and bovine pericardia were compared histologically and mechanically. The specimens were analyzed under light microscopy. The planar biaxial tests were performed on the tissue samples by applying synchronic loads along the axial (fiber direction) and perpendicular directions. The measured biaxial data were then fitted into both the modified Mooney‐Rivlin model and the anisotropic four parameter Fung‐type model. The modified Mooney‐Rivlin model was applied to the modeling of the bovine, equine, and porcine pericardia using finite element analysis. The equine pericardium illustrated a wavy collagen bundle architecture similar to bovine pericardium, whereas the collagen bundles in the porcine pericardium were thinner and structured. Wavy pericardia may be preferable candidates for transcutaneous aortic valves because they are less likely to be delaminated during crimping. Based on the biaxial tensile test, the specimens indicated some degree of anisotropy; the anisotropy rates of the equine specimens were almost identical, and higher than the other two specimens. In general, porcine pericardium appeared stiffer, based on the greater strain energy magnitude and the average slope of the stress–stretch curves. Moreover, it was less distensible (due to lower areal strain) than the other two pericardial tissues. Furthermore, the porcine model induced localized high stress regions during the systolic and diastolic phases of the cardiac cycle. However, increased mechanical stress on the bioprosthetic leaflets may cause tissue degeneration and reduce the long‐term durability of the valve. Based on our observations, the pericardial specimens behaved as anisotropic and nonlinear tissues—well‐characterized by both the modified Mooney‐Rivlin and the Fung‐type models. The results indicate that, compared to bovine pericardium, equine tissue is mechanically and histologically more appropriate for manufacturing heart valve prostheses. The results of this study can be used in the design and manufacture of bioprosthetic heart valves.

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Section: Introductionmentioning

confidence: 99%

Comparison of tensile properties of xenopericardium from three animal species and finite element analysis for bioprosthetic heart valve tissue

et al. 2019

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“…Cross-linking with GA is employed to increase the strength and durability of bioprosthetics and provides protection from enzymatic degradation [15]. However, conventional GA treatment decreases pliability (increased stiffness) of the bioscaffolds [15,16] and is associated with an increased risk for calcification and graft failure [8]. CardioCel is therefore crosslinked via a unique process based on an ultra-low concentration of monomeric GA, which provides thorough cross-linking without being prone to calcification [14,17].…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, the calcification process in children is accelerated compared with adults, and bioprosthetics have a much shorter lifespan in young patients [8].…”

Section: Introductionmentioning

confidence: 99%

Comparison of physical and biological properties of CardioCel® with commonly used bioscaffolds

Neethling

Puls

Rea

2018

Interactive CardioVascular and Thoracic Surgery

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OBJECTIVES: Durability of bioscaffolds cross-linked with glutaraldehyde and used in cardiovascular surgery is limited by biomechanical instability, calcification and reduced biocompatibility. This study compares CardioCel V R , a bovine pericardial scaffold engineered via the ADAPT V R process to ensure optimized biostability and biocompatibility, with the commonly used bioscaffolds. METHODS:Bovine pericardial scaffolds, cross-linked with 0.6% glutaraldehyde (XenoLogiX TM , PeriGuard V R ), dye-mediated photo-oxidized (PhotoFix TM ) and a non-crosslinked porcine scaffold (CorMatrix V R ), were compared with CardioCel (decellularized, cross-linked with 0.05% monomeric glutaraldehyde, detoxified) by thermal stability and mechanical tests. Biocompatibility and calcification were assessed in a juvenile subcutaneous rat model at 6 and 12 weeks. RESULTS:CardioCel displayed significantly higher (P < 0.01) cross-link stability (77.99 ± 0.64 C) than CorMatrix (57.88 ± 0.22 C) and PhotoFix (53.96 ± 0.41 C). Tensile strength of CardioCel (8.31 ± 3.36 MPa) was comparable with XenoLogiX (11.00 ± 5.43 MPa, P = 0.734), PeriGuard (16.44 ± 6.69 MPa, P = 0.136), PhotoFix (7.10 ± 6.11, P = 0.399) and CorMatrix (9.75 ± 2.61, P = 0.204). XenoLogiX and PeriGuard recorded the highest Young's modulus (67.01 ± 30.36 vs 95.67 ± 45.91 MPa), while CardioCel (50.21 ± 19.92 MPa) was comparable with CorMatrix (36.78 ± 10.47 MPa, P = 0.204) and PhotoFix (33.50 ± 10.24, P = 0.399). CorMatrix displayed a significantly (P < 0.05) greater stiffness (4.74 ± 0.77 MPa) at 10% strain than PeriGuard (3.73 ± 1.79 MPa), PhotoFix (1.59 ± 0.40 MPa) and CardioCel (3.39 ± 0.83 MPa). Differences in extractable calcium did not reach significance; however, the inorganic phosphorus content of PhotoFix (21.3 ± 9.0 mg/mg) was higher than CardioCel (11.35 ± 0.76 mg/mg, P = 0.004) or PeriGuard (10.7 ± 2.18 mg/mg, P = 0.002) at 12 weeks. CardioCel underwent a typical mild host-graft response with fibroblast infiltration and remodelling. Foreign body reactions were visible in both XenoLogiX and PeriGuard, with isolated fibroblast infiltration. PhotoFix showed severe inflammation and 2 implants were completely degraded at 12 weeks.CONCLUSIONS: CardioCel demonstrated optimized physical properties, minimal mineralization potential and superior biocompatibility. These results may benefit the long-term performance of this bioscaffold for cardiovascular surgery. The favourable characteristics of the comparator products were counterbalanced by less desirable features that may have negative implications on durability and performance when used in cardiovascular procedures.

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“…Alternative donor sources, such as scaffolds derived from xenografts, may be promising substitutes [34]; however, this strategy comes with its own hurdles, such as the difficulties of ensuring that the xenograft is a suitable anatomical substitute, the potential for zoonotic infections, and the possibility for long-term scaffold rejection due to xenospecific epitopes [35].…”

Section: Organ Scaffoldsmentioning

confidence: 99%