This is a stentless procine valve viewed from the bottom.
NOTE: The large opening, which combined with the normal architecture, allows for normal physiologic pressures across the valve after surgery.
This is a stentless aortic valve being fitted with sutures, which will secure it to the heart.
This picture shows an echocardiogram immediately after aortic valve replacement with a stentless tissue valve. It shows the normal 3 leaflets meeting centrally and normal human like valve function.
These are typical stented tissue valves, in which plastic or metal stents form the internal framework. The latest generation of these tissue valves have an 85% chance of lasting 15 years.