A multi-step approach in anti-calcification of glutaraldehyde-preserved bovine pericardium.
AIM: Bioprosthetic cardiovascular substitutes, manufactured from glutaraldehyde-preserved bovine or porcine tissues, are prone to calcification after implantation. The aim of the study was to evaluate the ultrastructure, material stability and calcification behaviour of glutaraldehyde-preserved bovine pericardium, treated with a multi-step anti-calcification process which addresses each of the major causes of calcification and tissue degeneration. METHODS: Bovine pericardium samples were divided into 2 groups. Group I (control) consisted of tissue fixed with 0.625% glutaraldehyde and Group II (study group) consisted of tissue fixed with 0.625% glutaraldehyde and exposed to a multi-step anti-calcification process. Ultrastructure was examined by scanning electron microscopy and material stability was assessed by mechanical testing, shrinkage temperature and enzymatic degradation. Calcification was assessed by histology (Von Kossa stain) and by atomic absorption spectrophotometry in the subcutaneous rat model. RESULTS: Bovine pericardium in the study group revealed less visible changes in the ultrastructure of the collagen matrix, improved material stability (P<0.05) and significantly (P<0.001) reduced calcification compared to control tissues (4.5+/-1.2 versus 136.03+/-11.39 ug/mg tissue). CONCLUSIONS: In conclusion, results demonstrate that the multi-step anticalcification process improved the material stability and reduced the calcification potential of bovine pericardial tissue. These improvements in the quality of the bovine pericardium should enhance the long-term durability of the tissue as a bioprosthetic substitute for cardiovascular application.