Objectives: Conventional glutaraldehyde fixation is conducive to calcification of bioprosthetic tissues. The aim of this study was to test calcification resistance of procyanidin-treated decellularized porcine aortic valve in a rat model.
Materials and methods: We performed cross-linking of the decellularized porcine aortic heart valves by procyanidins and observed morphologic performance and examined the tensile strength and cross-linking index. Then we implanted subcutaneous samples of procyanidin cross-linking decellularized valves, glutaraldehyde cross-linking decellularized valves, and decellularized valves in rats. The retrieved grafts were stained with hematoxylin-eosin and von Kossa and were analyzed with scanning electron microscopy and x-ray energy dispersive spectroscopy (EDS) after 21 and 63 days.
Results: After decellularized and cross-linking pretreatment, the procyanidin cross-linked leaflets were soft and stretchable. In addition, the cellular components of the porcine aortic heart valve leaflets were completely removed, and the extracelluar matrix was maintained completely. Examination of tensile strength revealed a significantly higher tissue resistance to tension in procyanidin cross-linked tissue than in other tissues, including the glutaraldehyde group (P< .05), even though the extents of cross-linking of each group were roughly the same at approximately 90%. Histopathologic examination showed that the procyanidin cross-linked valve matrix had no significant calcification, and there were no calcium peaks in the EDS profile of procyanidin cross-linked samples in the 21-day and 63-day rat studies.
Conclusion: This study demonstrated that procyanidin cross-linked decellularized heart valves can resist calcification to some extent.