 After returning from Afghanistan, Duke joined the faculty of the University of Texas Medical School at Houston, where he was a professor of surgery.Among his many responsibilities, Duke served as special assistant to the president of the UT Health Science Center and held one of the distinguished professorships at the UT Medical School as the John B. Holmes Professor of Clinical Sciences.He established Houston's Hermann Hospital Life Flight operations in 1976 and helped establish its trauma and emergency services, of which he served as director.