When pediatric surgeon Allan Goldstein entered the operating room to separate conjoined twins, he did so with the knowledge that one would have to die in order to save the other. He recalls the enormous surgical and ethical challenges.

http://www.spiegel.de/international/world/surgeon-on-separating-siamese-twins-the-first-time-i-cried-in-the-operating-room-a-1189755.html