:snip: Qadgop
“And I believe so far I’m the only poster in the thread that has removed a human head from its body.”
:eek:
Then KarlGauss showed up, and I’m no longer so special… 
Assuming it would be possible, it is not a brain or head transplant at all. It’s a transplanting a new body to the brain.
My great uncle had his brain removed…with a baseball bat. It took awhile, or that’s what the police said.
As noted, since we can’t even begin to start such a thing with current knowledge, it’s not a factual question.
If we’re looking for ‘plausible reasons to use in a science fiction story to justify brain instead of head transplant’, then it’s certainly possible that it might turn out that immune rejection is much easier to control within the brain itself than other tissues, so that transplanting a brain leads to fewer complications than transplanting a head. Of course, it’s also possible that it turns out the other way.
OK, I’ve taken off more than one head as well, and I vote for the head transplant. That’s going to involve a ton less trauma to the brain, which is the only thing that we really care about anyway. It’s not like there’s a lot of slack in the cranial nerves or vascular connections inside the skull that would allow you to connect them up without the brain actually resting on the base of the skull already. Then you get to moosh the brain around to fit into a container that wasn’t tailored for it. No, it’s best to leave it in the packing case and just deal with the external hookups.
Hooking up the conduits in the neck is a damn sight easier: work from the inside out, with plenty of light and access, and you can take the head off at C6 or C7 on the head donor and C1 or C2 on the head recipient to give yourself plenty of extra length to work with if needed. That way you can also stagger your splices, which is tidier.
Well that can’t be true…I mean, they do limb reattachments all the damn time (ok, not all the time, but they are done.) The limb is never back to 100% of it was, but patients do regain some functionality. Unless the surgeons just put the two ends of the nerves next to each other and they just heal themselves? 
I’ll admit I don’t know anything about limb attachment surgery, but obviously some sort of nerve repair/reconnection is being done, yes?
Um, are we necessarily talking about transplanting a head or brain to an animal of the same species?
Oh I remember those flip books where you could change heads, bodies and feet to make new animals. This has evil scientist potential!