1. Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
2. Department of Gastroenterological Surgery, Yokohama Municipal Citizen’s Hospital, Yokohama, Japan
3. Department of Cardiovascular Surgery, Yokohama Municipal Citizen’s Hospital, Yokohama, Japan
4. Department of Inflammatory Bowel Disease, Yokohama Municipal Citizen’s Hospital, Yokohama, Japan