Hi shah4u,
This is such a confusing time, figuring out what to do. Doesn't make it any easier when the surgery date is so close either. Plus it's a shock suddenly finding out the valve needs fixing in the first place, let alone trying to figure out what to do next.
One of my doctor surgeons told me, when pushing for tissue, doctors are mostly worried that the patient won't maintain the warfarin treatment after they get the mechanical valve. Maybe the doctor thinks the patient isn't suited to warfarin treatment, they are the type that will forget to take their daily dose or will blow off the INR testing. Because if you get a mechanical valve, you have to do the warfarin part like a habit. You have to do it regularly without fail.
Now if you get a tissue valve, you will have to have another open heart surgery sooner or later. Since you are young, it will be sooner. Before that, the tissue valve will begin to fail just like your native valve did in the first place. As the tissue valve fails, your heart starts to have to work too hard to push the blood through the failing valve. At that point you'll probably start to feel it. You'll start to see your doctor much more frequently for echo tests which are expensive. Then when you finally get the next open heart surgery, you'll have to pay your share of the cost, take time off from work and deal with recovering from the surgery.
If you get a mechanical valve, the odds are you will never have to go through another open heart surgery. But the tradeoff is a commitment to warfarin.
If you feel at this point you don't want to deal with warfarin, you could just go with a tissue valve this time around. Live your life without anticoagulation for now. Do all the risky things without the warfarin part of the risk puzzle. Then when the time inevitably comes, replace the failing tissue valve with a mechanical valve and take on the warfarin part. Being more experienced at that point, you probably won't choose to replace with another tissue valve since at that point you'll know first hand what will happen to the tissue valve sooner or later.
So maybe your doctors are looking at you and thinking, right now at this stage in his life, this patient is not a good candidate for warfarin therapy. We don't get the feeling he will be able to keep it going. If he is unable to keep up with the warfarin therapy, he will be at high risk for a stroke. We would prefer to give him a tissue valve even if this means he has to have another open heart surgery sooner or later. Because the risk of stroke from not doing the warfarin properly is higher than the risk of dying during the second surgery. Something like that? Maybe ask them?
Remember the risk of dying during the second surgery doesn't include all the other related issues with a second surgery like how the tissue valve gradually fails before the second surgery, how you have to take time off work, deal with recovery and all the other costs. But bottom line, it's your body, your life, your choice. Good luck!