Accelerated fatigue test of a new stentless porcine aortic bioprosthesis
AIM: To investigate the accelerated fatigue durability of a new kind of stentless porcine aortic bioprosthesis. METHODS : With the use of the accelerated wear testing equipment (WET Medical, Inc, Beijing), three 19-mm new stentless porcine aortic bioprosthesis (group A) and three 19-mm XJ stented porcine (group B ) were tested to evaluate their long-term durability. After 50 million and 100 million cycles, the appearance of wearing of all the specimens was examined. The biomechanical characteristics (values of elastic modulus and ultimate tensile strength ) of stentless bioprosthesis were tested after 50 million and 100 million cycles and compared with those of fresh bioprosthesis (group C ). RESULTS: No significant wear was observed in stentless group or stented bioprosthesis group after 100 million cycles. Fatigue test showed that the value of elastic modulus and ultimate tensile strength after 50 million cycles was higher than that after 100 million cycles and the value of ultimate tensile displacement was lower in group A. The ultrastructure of collagen fibers in group A was well arranged after 50 million cycles, but the ultrastructure was badly arranged following 100 million cycles. CONCLUSION: The results of our experiments show that the durability of the new stentless porcine aortic bioprosthesis meets the standard of ISO 5840 and GB-12279-2000 guideline.
NETL
NSTL
万方数据
维普
