My son is 29 years the dr has told him the enlargement is 5.1 He has had surgery before.They took out his main arotic & replaced it with his pulmonary valve & replaced it with a human valve.Should he have limitations tell they decide what to do or how soon should they try to fix the enlargement.What will have to be done to fix the enlargment. I am just a worried mom,that would like to know more about the problem. Thank you....