1. Division of Gastrointestinal Surgery, Department of SurgeryGraduate School of Medicine, Kobe University Kobe Japan
2. Division of Minimally Invasive Surgery, Department of SurgeryGraduate School of Medicine, Kobe University Kobe Japan
3. Division of Community Medicine and Medical Network, Department of Social Community Medicine and Health ScienceGraduate School of Medicine, Kobe University Kobe Japan