Degenerative Calcification of Pericardial Bioprostheses: Comparison of Five Implantation Methods in a Rabbit Model

BACKGROUND AND AIM OF THE STUDY: The degenerative calcification of bioprosthetic heart valves remains a clinical challenge, especially among young adults and children. Animal models that are based on subcutaneous and intramuscular implantation and are typically used to assess interventions to prevent bioprosthetic heart valve calcification do not reflect actual hemodynamic stress and lack direct blood contact. Thus, the study aim was to investigate bioprosthesis calcification at different implantation sites. METHODS: The calcification degrees of five valve implantation methods, namely subcutaneous, intramuscular and intravenous implantation, and arterial and venous patch angioplasty, were simultaneously investigated in 10 New Zealand White rabbits. RESULTS: Ultrasonography and computed tomography images showed vascular patency to be well maintained in all implanted vessels. Histologically, cellular infiltrates around the implant and within the collagen fibers were only found in the intravenous implantation group, which also had the highest calcium level among the methods. CONCLUSION: The present study was the first to compare the degree of calcification after applying five implantation methods simultaneously in one animal species. The rabbit intravenous implantation model, which involved direct contact with blood factors, is expected to serve as a useful animal model for research into the prevention of bioprosthetic heart valve degeneration.restrictio