Capone was born in New York, so there was no chance of deportation. Had he survived into the fifties, antibiotics could have cured his VD, but the damage could not have been reversed. Given his deteriorating condition when he went to prison, he would never return to his Prohibition liquor Mafia heydays.
Even in the early 1920's Salvarsan would probably have prevented the damage. But Capone didn't get himself treated, perhaps being unwilling to admit to himself or to his wife Mae that he had contracted the disease, perhaps just hoping that--like its early symptoms--it would just go away. https://books.google.com/books?id=I48z-9NgqAoC&pg=PA17