Temporal Changes in the Surgical Pathology of Prosthetic Aortic Valves: A Study of 157 Cases Spanning 26 Years (1970–1995)

Kent, Peter D.; Tazelaar, Henry D.; Edwards, William D.; Orszulak, Thomas A.

doi:10.1016/s1054-8807(97)00040-9

Cited by 32 publications

(16 citation statements)

References 26 publications

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“…Fibers re‐orientation, strain and the changes in mechanical behavior can be detected above 65 × 10 6 cycles, ∼2 years after being implanted 13. With these conditions, to design bioprostheses with durability of 30 years, (1000 million cycles or valve movements) seems an unattainable objective 1–4. Nevertheless, prosthesis durability can be improved if its hemodynamical behavior is significantly improved.…”

Section: Discussionmentioning

confidence: 99%

“…13 With these conditions, to design bioprostheses with durability of 30 years, (1000 million cycles or valve movements) seems an unattainable objective. [1][2][3][4] Nevertheless, prosthesis durability can be improved if its hemodynamical behavior is significantly improved. If we get a minimum compliance (strain to stress ratio) on each valve closing and opening, the valve leaflet wasted energy will also be minimum and therefore, in theory, at less energy consumption higher fibers integrity and higher durability of valve leaflet.…”

Section: Discussionmentioning

confidence: 99%

“…Nowadays, the durability of the cardiac bioprosthesis is a major issue. [1][2][3] Biological bioprosthesis is only used as a first choice in the short amount of indications of tricuspid replacement 4 and in replacement of aortic valve in old patients, 5 in spite of its good hemodynamic behavior and the fact that a patient with a biological bioprosthesis does not need to take anticoagulants. They also have to be employed in mitral situation on young patients of countries or regions where an adequate control of the intake of anticoagulants is impossible.…”

Section: Introductionmentioning

confidence: 99%

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Energy consumption as a predictor test of the durability of a biological tissue employed in cardiac bioprosthesis

Páez¹,

Claramunt²,

Herrero³

et al. 2008

J Biomedical Materials Res

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The mechanical behavior of the young bull pericardium in a fatigue test has been studied. This material is a similar tissue to those used in valve leaflet construction for a cardiac bioprosthesis. The consumed energy on each test was evaluated and afterwards used as a predictor of the biomaterial strength. Two-hundred and nine samples were tested to cyclical fatigue. The cut-off point to determine the sample quality was whether or not they resisted at least 4500 cycles. Only 22 samples withstood over that point (10.52%). The samples were classified according to their fatigue behavior in excellent, undefined and unsuitable. By using as a reference the consumed energy in the first 25 cycles, we could distinguish correctly (between 93.2 and 96.1%) the unsuitable material and most of the excellent (between 78.1 and 95.2%). From the rejected material 77% was really detachable and from the accepted, only 50% was excellent, with an equal methodology. The receiver operating characteristics curve was employed to establish decision levels when selecting samples, being 0.85 the best area (theoretical maximum value of 1). It is concluded that the energy wasted is a good predictor of the strength of the tissue. More than 90% of the unsuitable material and 50% of the excellent material (5% of all the material) is detected with this method.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Energy consumption as a predictor test of the durability of a biological tissue employed in cardiac bioprosthesis

Páez¹,

Claramunt²,

Herrero³

et al. 2008

J Biomedical Materials Res

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“…At present, the duration of a cardiac bioprosthesis is not guaranteed indefinitely. Their mechanical failure after a decade of implantation is common,2–5 but it can also occur early 6, 7. The most frequent cause of valve replacement is structural failure, followed at a distance by infection, thrombosis, and paravalvular regurgitation 1–3…”

Section: Introductionmentioning

confidence: 99%

Determination of the force necessary for the propagation of tears in ostrich and calf pericardium

et al. 2006

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The durability of prosthetic heart valve leaflets made of biological materials is limited. A tear in the biomaterial accelerates their early failure, but microtearing of the collagen fibers may be responsible for their medium-term failure. We studied the force necessary to propagate tearing in two biomaterials: ostrich and calf pericardium. One hundred twenty samples of each tissue were tested in an Elmendorf pendulum capable of measuring the force required to tear a tissue in which a predefined slit had been made. The forces required to produce tears, ranging between 2.5 and 0.25 cm in length, were determined. For ostrich pericardium, this force ranged between 67.67 and 4.80 newton, while that required to tear the same lengths of calf pericardium ranged between 70.67 and 4.70 newton. The function that relates the tearing force to the length of the tear was expressed as follows: y = 20.62x + 1.77x(2) (R(2) = 0.923) for ostrich pericardium and y = 45.57x - 7.21x(2) (R(2) = 0.936) for calf pericardium, where y is the force in newton and x is the length in centimeter. Calf pericardium was found to have a greater resistance to tearing. However, these results should be interpreted with caution owing to the fact that the thickness of the majority of the samples of ostrich pericardium was significantly less than that of calf pericardium. A more careful selection and utilization of adult ostrich pericardium would probably improve these results.

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“…Despite their excellent hemodynamic behavior and the fact that they do not require long‐term anticoagulation, cardiac bioprostheses are still far from being able to substitute completely for mechanical prostheses in valve replacement because of their limited durability (1–4), which is estimated to range between 10 and 12 years. Mechanical fatigue, with or without calcium deposition, and hardening of the biomaterial, with greater rigidity in the cardiac valve leaflets, are recognized as causes that make valve replacement necessary (2,3,5,6).…”

mentioning

confidence: 99%

Changes in the Mechanical Properties of Chemically Treated Bovine Pericardium After a Short Uniaxial Cyclic Test

Claramunt¹,

Álvarez-Ayuso²,

García-Páez³

et al. 2012

Artificial Organs

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The mechanical behavior of calf pericardium, a biomaterial utilized in the manufacture of cardiac bioprostheses, in response to a short tensile cyclic test has been evaluated. The trial involved 120 samples cut longitudinally or transversely, subjected to 10 cycles until a stress of between 1 and 3 MPa was reached. Tests of hardness and tear propagation were performed, and the results were compared with a control series. The energy loss was also computed, and it was approximately 10-fold greater in the first cycle than the loss in the subsequent nine cycles. Despite this singularity, they correlated very precisely. The effect of the direction in which the tissue is cut on energy loss was not significant nor the difference between hardness prior to and after testing. The results of the tear propagation tests gave no statistical differences prior to and after testing. From the obtained results, it seems that the test carried out does not affect significantly the mechanical properties of calf pericardium.

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Temporal Changes in the Surgical Pathology of Prosthetic Aortic Valves: A Study of 157 Cases Spanning 26 Years (1970–1995)

Cited by 32 publications

References 26 publications

Energy consumption as a predictor test of the durability of a biological tissue employed in cardiac bioprosthesis

Energy consumption as a predictor test of the durability of a biological tissue employed in cardiac bioprosthesis

Determination of the force necessary for the propagation of tears in ostrich and calf pericardium

Changes in the Mechanical Properties of Chemically Treated Bovine Pericardium After a Short Uniaxial Cyclic Test

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