Complex sentence: His fascination with anatomy went as far as replacing his right arm and leg by mechanical constructs, and his jugular vein with a transparent external tube, to monitor his own circulation.
Split into simpler sentences: His fascination with anatomy was very great he went as far as amputating his right arm and leg, replacing them with mechanical constructs. He also replaced his jugular vein with a transparent external tube, in order to monitor his own circulation.