Transplant is a treatment for kidney failure using a healthy kidney from a living or deceased donor that can help patients live a longer, more normal life than dialysis treatment.
Yeah, but if you get the right beans type, it can form a new kidney and then you'll have two kidneys again after the transplant. If you get it wrong, then there's a chance of rejection, though. So most doctors don't use beans.
It's more that there's a higher risk of complications if they remove the old kidneys. However, they do start taking them out if you've had more than two transplants.
As many as necessary, really. The only reason they start getting removed is because of the risk of infection and stuff being higher than the risk of complications with the surgery after a certain point.
It's complicated, subjective, and probably varies country-to-country.