Indentation hardness: A simple test that correlates with the dissipated-energy predictor for fatigue-life in bovine pericardium membranes for bioprosthetic heart valves.

The aim of this study was to evaluate the variation of hardness with fatigue in calf pericardium, a biomaterial commonly used in bioprosthetic heart valves, and its relationship with the energy dissipated during the first fatigue cycle that has been shown to be a predictor of fatigue-life (García Páez et al., 2006, 2007; Rojo et al., 2010).

Changes in the mechanical properties of chemically treated bovine pericardium after a short uniaxial cyclic test.

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.

Fatigue behaviour of young ostrich pericardium.

Young ostrich pericardia (biomaterial under study for manufacturing cardiac valve leaflets), has been subjected to biaxial tension fatigue until breakage. Supraphysiological values of pressure (1 to 6 atm) have been employed to accelerate damage and, therefore, to reduce testing time but at physiological frequency in order to avoid viscoelastic behaviour changes. The lifetime fatigue curves have been obtained and large scatter has been observed in the results but this can be strongly reduced with adequate material selection.

Biocompatibility and calcification of bovine pericardium employed for the construction of cardiac bioprostheses treated with different chemical crosslink methods.

The use of biological materials in the construction of bioprostheses requires the application of different chemical procedures to improve the durability of the material without producing any undesirable effects. A number of crosslinking methods have been tested in biological tissues composed mainly of collagen. The aim of this study was to evaluate the in vitro biocompatibility, the mechanical properties, and in vivo calcification of chemically modified bovine pericardium using glutaraldehyde acetals (GAAs) in comparison with glutaraldehyde (GA) treatment.

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

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.

Mechanical resistance of a new biomaterial, ostrich pericardium, and a new method of joining tissues combining suturing and a biological adhesive.

We studied the mechanical behavior in response to tensile stress of samples of ostrich pericardium bonded with a cyanoacrylate glue or sewn with a rectangular, overlapping suture that was subsequently sealed with the same bioadhesive. Seventy-two trials were performed in three series of 24 samples each: series AG, glued with an overlap of 1 cm2; series ASG, sewn with a rectangular, overlapping suture and sealed; and series AC, control samples that were left intact. The mean stress at rupture in series AG (glued) was 0.