Aortic valve replacement done with pig or fake one?

AVR: Aortic valves can be replaced with either mechanical valves or bio prosthetic, taken from animals and treated to prevent rejection. There are different reasons for choosing either valve such as age and treatment with anticoagulants. Individuals who do not wish to be on meds such as Coumadin (warfarin) may have a bioprosthetic valve, however, younger individuals usually have mechanical valves.