we examined the long-term clinical function and fate of allograft aortic valves , preserved by two differing methods , for aortic valve replacement : ( 1 ) fresh allografts stored at 4 degrees c refrigeration ( group i ) and ( 2 ) viable allografts cryopreserved in liquid nitrogen at -196 degrees c ( group ii ) .
C0003501
aortic valves
C0003506
aortic valve replacement