First : "How many American patients currently on the national organ waiting list were denied access to healthy hearts and lungs as a result of Santillan's two transplant surgeries?"

Well, two (maybe one if they would've gone to the same recipient). That's sort of how these transplants work.

Second, you're blaming the parents for crossing the border illegally to get their child the treatment they need to live? If Canada had a treatment that wasn't available in the US and my child needed it to live, I wouldn't hesitate to go there, legally or not, to get that treatment. The argument is basically, "If they wanted their child to survive they should've been born in a better country."