Board Thread:Manga/@comment-30632294-20161129075531/@comment-26495049-20161129162131

While this might be possible with modern-day surgery equipment and knowledge, I'm not entirely sure the wall people possess the medical know-how to perform a spinal fluid extraction without endangering the life of the shifter.

Since the only known way to kill a titan shifter is to destroy their spine, I wouldn't risk the life of the Coordinate holder on such a risky operation. Interesting theory though.