1. Department of Minimally Invasive Surgical and Medical Oncology, Fukushima Medical University, Fukushima, Japan
2. Department of Surgery, Southern TOHOKU General Hospital, Koriyama, Japan
3. Department of Surgery, The Takeda Healthcare Foundation Takeda General Hospital, Aizuwakamatsu, Japan
4. Department of Surgery, Fukushima Rosai Hospital, Iwaki, Japan
5. Department of Surgery, Ohta Nishinouchi Hospital, Koriyama, Japan
6. Department of Surgery, Iwaki City Medical Center, Iwaki, Japan
7. Department of Gastrointestinal Tract Surgery, Fukushima Medical University, Fukushima, Japan
8. Department of Surgery, Shirakawa Kosei General Hospital, Shirakawa, Japan
9. Department of Internal Medicine, Aidu Chuo Hospital, Aizuwakamatsu, Japan
10. Department of Surgery, Tsuboi Hospital, Koriyama, Japan