1 Division of Digestive Surgery (Gastric Surgery Division), Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii‑cho, Kawaramachi‑hirokoji, Kamigyo‑ku, Kyoto, 602‑8566, Japan.
2 Division of Digestive Surgery (Gastric Surgery Division), Department of Surgery, Kyoto Prefectural University of Medicine, 465 Kajii‑cho, Kawaramachi‑hirokoji, Kamigyo‑ku, Kyoto, 602‑8566, Japan. skomatsu@koto.kpu-m.ac.jp.