Only on the “CBS This Morning” podcast, Dr. Tom Catena joins CBS News chief medical correspondent Dr. Jon LaPook to explain how he found himself in the Nuba mountains of Sudan. Seeing as many as 400 patients a day at Mother of Mercy Hospital, Dr. Catena is the only surgeon within 200 miles in the war-torn region. The subject of a new documentary - "The Hear of Nuba" - Dr. Catena discusses the dire conditions, the need for resources and his hope for the future.