Here's the science.
I don't know why, but a heart-lung transplant is more likely to be successful than a lung transplant alone.

So... imagine three people: A, B and C. A needs a heart transplant. B has diseased lungs but a healthy heart, so needs lungs but will get a new heart anyway as part of the deal. C is a tissue-match for B, is healthy, and has recently been hit by a bus.

You take the heart and lungs from C and put them into B, and remove the healthy heart from B and put it into A. Hence B is not only a heart donor, but a heart donor who can talk about it afterwards.
( Enzyme is powered by sunlight, Tue 25 Aug 2009, 15:10, 2 replies, latest was 16 years ago)

Everybody wins
Except the dead one.
( Bert Monkeysex is waiting for the mods to delete him, Tue 25 Aug 2009, 15:11, Reply)

Heart lung transplants are better because you have to less cutting and stitching.

(PsychoChomp, Tue 25 Aug 2009, 15:13, Reply)

Is it really that simple?
Blimey.
( Enzyme is powered by sunlight, Tue 25 Aug 2009, 15:17, Reply)

Well half of the hearts job is to send stuff to and from the lungs,
if that whole system is in place without having to stitch it together then that's a bonus.
Also tissue rejection will start where the implanted organs is attached to the host organs, less links the better.
(PsychoChomp, Tue 25 Aug 2009, 15:19, Reply)

Makes sense to me.
The "blimey" was indicative of one of those forehead-slapping moments.
( Enzyme is powered by sunlight, Tue 25 Aug 2009, 15:20, Reply)