The subchoroidal approach to the third ventricle: surgical anatomy according to Galen.

THE SUBCHOROIDAL APPROACH has taken its place among the surgical access routes to the third ventricle. Eighteen centuries ago, in his major anatomic work, Galen detailed with astonishing accuracy the anatomy of the structures around the third ventricle and the procedure for exposing this cavity by entering the lateral ventricles and elevating its roof. Even more surprising is Galen's pioneering description of surgical maneuvers of the third ventricle in living animals in a way that anticipated the modern subchoroidal approach.