1. Department of Surgery, Saiwaicho Memorial Hospital, Okayama - Japan
2. Department of Internal Medicine, Saiwaicho Memorial Hospital, Okayama - Japan
3. Department of Gastroenterological Surgery, Okayama University of Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama - Japan
4. Department of Anesthesiology, Okayama University of Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama - Japan