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

Abstract

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.

Fatigue Damage of Collagenous Tissues: Experiment, Modeling and Simulation Studies

“…In light of these points, García Páez et al . 49,50 have adopted a more physiologically relevant cyclic pressurization experimental set up for characterizing the fatigue properties of gluraladehyde-treated pericardium. They argue that the tissue durability can be estimated from the energy consumed during the initial loading cycles.…”

Caracterización mecánica de materiales de base colágeno para aplicaciones cardiovasculares

“…García Páez et al [80], dos años después, ensayaron a fatiga probetas de pericardio de toro. Se comprobó que el área contenida bajo la curva tensión -deformación en los primeros ciclos de fatiga es un buen indicador de la durabilidad de la probeta.…”

“…Dicho parámetro ha sido propuesto como método de selección del pericardio, puesto que su valor está relacionado con la durabilidad del material [80][81].…”