Clinical Factors of Delayed Perforation after Endoscopic Submucosal Dissection for Gastric Neoplasms oleh Yoshinobu Yamamoto, Hogara Nishisaki, Hideki Sakai, Nagahiro Tokuyama, Hiroaki Sawai, Aya Sakai, Takuya Mimura, Saeko Kushida, Hidetaka Tsumura, Takeshi Sakamoto, Ikuya Miki, Masahiro Tsuda, Hideto Inokuchi