Porcine pericardial membrane subjected to tensile testing: preliminary study of the process of selecting tissue for use in the construction of cardiac bioprostheses

The durability of cardiac bioprostheses is limited fundamentally by structu ral failure due to mechanical fatigue and calcification. In the present rep ort, we analyze, using an in vitro hydraulic simulator to test tensile stre ngth, the mechanical behavior of porcine pericardium for the purpose of est ablishing the criteria for selecting the biomaterial, taking into account b oth morphological criteria (thickness and homogeneity of the specimens) and mechanical criteria (stress at breaking point), using the epidemiological model of paired samples. The stress at breakage was found to range widely f rom 24.07 MPa to 100.29 MPa, although we observed no statistically signific ant differences when comparing the mean results in the different regions an d zones of the pericardium being studies. The application of the selection criteria in the present series resulted in an excellent mathematical fit in terms of the stress/elongation ( R-2> 0.95), making it possible to establi sh, by means of linear regression, the prediction of the tensile strength i n one zone on the basis of the values observed in its paired specimen. (C) 2001 Kluwer Academic Publishers.