If repeat open heart surgeries weren't so risky, I think we all would choose a tissue valve each time. I had porcine at age 34, told it would last 15 yrs, ha! I got 11 yrs and that was considered really good. Then, mechanical at age 45, and boy was it tempting to get a tissue (homograft) when I got BE and needed another surgery at age 54. But, I chose another mechanical and I'm good with that. It took 3 hours for my surgeon to cut thru the scar tissue from my previous surgeries. You just appreciate the years you get with those quiet tissue valves!