Hancock and Carpentier-Edwards porcine bioprostheses are the two most widely implanted biological valves and have become the standard by which the performance of newer tissue valves are measured. New guidelines for reporting valve-related complications have provided more comprehensive evaluations and meaningful comparison of the long-term results of valve substitutes. Clinical investigations directly comparing the Hancock and Carpentier-Edwards bioprostheses have shown no significant differences in the long-term performance of these two valves. The incidence of structural valve deterioration for porcine bioprostheses begins to increase 5 to 6 years after implantation. For patients undergoing aortic valve replacement, estimates of freedom from structural valve deterioration at 10 and 15 years range from 76% to 91% and 37% to 63%, respectively. The incidence of structural valve deterioration may be offset by the limited survival of older patients; thus, the durability of a bioprosthesis may be sufficient for the majority of these patients. The long-term results of the porcine bioprosthesis have been satisfactory, particularly in older patients and those undergoing aortic valve replacement. The performance of the Hancock modified orifice (MO) bioprosthesis is comparable with that of other bioprostheses despite its more complex fabrication process. Although it does not offer any distinct advantages in terms of durability, the Hancock MO valve is associated with lower pressure gradients and larger calculated valve areas compared with other porcine valves in the smaller sizes. Based on currently available data, there are no distinct differences in the performance of the second-generation porcine bioprostheses compared with the first-generation valves, and any purported advantages need to be confirmed with long-term evaluations.
View details for PubMedID 8843517