1. Department of Gastroenterological, Breast and Endocrine Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755‑8505, Japan
2. Department of Surgery, Kanmon Medical Center, National Hospital Organization, Shimonoseki, Yamaguchi 752‑8510, Japan
3. Department of Surgery, Shimonoseki Medical Center, Japan Community Health Care Organization, Shimonoseki, Yamaguchi 750‑0061, Japan
4. Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565‑0871, Japan
5. Department of Biomolecular Engineering Applied Molecular Bioscience, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755‑8611, Japan
6. Department of Information Science and Engineering, Yamaguchi University Graduate School of Sciences and Technology for Innovation, Ube, Yamaguchi 755‑8611, Japan
7. Department of Kampo Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734‑8553, Japan
8. Department of Digestive Surgery, Kawasaki Medical School, Kurashiki, Okayama 701‑0192, Japan