I don't think OP is mentioning the same doctor 40 years later. They mention "such" doctor:
"ast forward to today, and 40 years later such doctor called him and said"
no, it was in fact the same doctor, he is really old now, that said it wasn't the same one who ended up performing the surgery
no, it was in fact the same doctor, he is really old now, that said it wasn't the same one who ended up performing the surgery