Biomechanics of the fresh and conserved bovine pericardium

The use of biological membranes in surgeries is a reality for years, and one of the most used is the bovine pericardium, so the purpose of this research is to describe the bovine pericardium's biomechanics by comparing two directions of a test, one parallel to the longitudinal heart axis and one perpendicular. 20 adult bovine pericardium were tested for the maximum rupture force and rupture elongation, collecting four samples of each pericardium direction. In phase 2, eight pericardia were conserved for 4 months in a 98% glycerine solution, and the solution in which they were submerged was microbiologically analysed monthly. The Mann-Whitney test was used; there was a very significant difference between the perpendicular and parallel groups (p = .0001). The T test showed no significant difference for the rupture elongation (p = .0938). In pericardium preserved in glycerine, the outliers were removed regarding the maximum rupture force, and a Boxcox transformation was performed (λ = 0.25). Outliers were removed for the rupture elongation, and Bartlett's test (p = .7836), and Cramer-Von Mises (p = .5033) were performed and then, the analysis of variance (p < .0001), followed by the Tukey test at 5%. In the microbiological analysis, there was no presence of microorganisms during conservation. The research has shown that the pericardium collection direction influences its resistance and it can be stored in glycerine for 4 months without losing biomechanical characteristics.