1. Department of General Surgery and Pancreatic Surgery; Fujita Health University; 1-98 Dengakygakubo, Kutsukake-cho, Toyoake, Aichi 470-1192 Japan
2. Toyota Regional Medical Center; Toyota Japan
3. Department of Gastroenterological Surgery; Yokohama City University Graduate School of Medicine; Yokohama Japan
4. Department of General Surgery, Graduate School of Medicine; Chiba University; Chiba Japan
5. Department of Surgery; Teikyo University; Tokyo Japan