1) Department of Gastroenterological Surgery, Saitama Medical University International Medical Center, Saitama, Japan
2) Quality Management Center, Saitama Medical University International Medical Center, Saitama, Japan
3) Department of Patient Safety Management, Saitama Medical University International Medical Center, Saitama, Japan

Kojun Okamoto¹⁾²⁾, Isamu Koyama¹⁾²⁾, Masayasu Aikawa¹⁾, Katsuya Okada¹⁾, Yukihiro Watanabe¹⁾, Yuichiro Watanabe¹⁾, Kenichiro Takase¹⁾, Shinichi Sakuramoto¹⁾, Shigeki Yamaguchi¹⁾, Nobutaka Kawai³⁾