1. Department of Gastroenterology, Southern-Tohoku General Hospital, Koriyama, Japan
2. Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Fukushima, Japan
3. Department of Gastroenterology, Shin-yurigaoka General Hospital, Kawasaki, Japan
4. Department of Gastroenterology, Utsunomiya Memorial Hospital, Utsunomiya, Japan
5. Department of Gastroenterology, Hyogo Prefectural Awaji Medical Center, Sumoto, Japan
6. Department of Surgery, Southern-Tohoku General Hospital, Koriyama, Japan