I agree with Lyn that this thread is very good to have for others to reference that have this same concern.
And yes, the pig valve is the exact valve from the pig. During my tour of Edwards, they gave some great details about these. They do not use a vast majority of those because they have flaws. The "cow valve" is actually hand sewn from the pericardial tissue. It is tested and measured so that the 3 valve flaps cut from this tissue have exactly the same thickness. The valve is sewn together so that the flaps are perfectly aligned. After the tour, I felt very comfortable with a bovine tissue valve in me!
And yes, the pig valve is the exact valve from the pig. During my tour of Edwards, they gave some great details about these. They do not use a vast majority of those because they have flaws. The "cow valve" is actually hand sewn from the pericardial tissue. It is tested and measured so that the 3 valve flaps cut from this tissue have exactly the same thickness. The valve is sewn together so that the flaps are perfectly aligned. After the tour, I felt very comfortable with a bovine tissue valve in me!