Vader vs. Grievous...I think Grievous' lungs were good, while Anakins were barely working and required an oxygen rich mixture. Of course, it's absurd that with all the tech they couldn't fix Anakin's lungs, but that goes back to Palpatine keeping Vader a semi-cripple.
That's not that surprising. Star Wars medical tech is schitzo, just like everything else (gigaton laser cannons and Napoleonic infantry squares do not belong in the same universe). Women dieing in childbirth is still common enough that no one thinks its odd. Droid doctors can't diagnose or treat basic complications. It seems like everything is done with Bacta and their biotech pretty well sucks horribly, outside of cloning. I don't think that they know how to do live organ transplants. I'm not sure anyone in universe has even considered the possibility.