Jeepers! They actually had a patient that they reoperated on to replace mechanical valve with a tissue valve? Holy Smokes!!
I've seen this here with one member, she was in her late 50s early 60's (IIRC) and her surgeon needs a good solid hard kick up the arse. She had known bleeding risks and I would have classified her as "contraindicated for anti-coagulation", yet not in the opinion of her surgeon (who very clearly did not do due dilligence on that), post surgery she had bleed after bleed after bleed.That is what they said, my guess is was some time after original to make sure the patient wanted to go through it again. Personally it could be a myth. I went mechanical to be 1 and done.
She had to be re-operated after they conceded it was a bad choice to begin with.
She was not (by her own admission) even remotely healthy (years of alcoholism other substances and tobacco), but still her surgeon did that ... I can only suspect he had another agenda.