1. Department of Surgery Tohoku University Graduate School of Medicine Sendai Japan
2. Department of Gastroenterological Surgery Miyagi Cancer Center Natori Japan
3. Department of Surgery Tohoku Rosai Hospital Sendai Japan
4. Department of Surgery Iwate Prefectural Iwai Hospital Ichinoseki Japan
5. Department of Gastroenterological Surgery Iwate Prefectural Central Hospital Morioka Japan
6. Department of Surgery Aizawa Hospital Matsumoto Japan
7. Department of Surgery Saka General Hospital Shiogama Japan
8. Department of Surgery Okayama Saiseikai General Hospital Okayama Japan
9. Department of Surgery National Hospital Organization Iwakuni Clinical Center Iwakuni Japan