Complex sentence: He was operated on by Lipmann Kessel, at the St Elizabeth Hospital in Arnhem, who with superb surgery managed to save the Brigadier's life and after further recuperation, he managed to escape with the help of the Dutch underground.
Split into simpler sentences: He was operated on by Lipmann Kessel, at the St Elizabeth Hospital in Arnhem, who with superb surgery managed to save the Brigadier's life. After a period of recuperation, he managed to escape with the help of the Dutch underground.