title: Retraction Note: Notice of formal retraction of articles by Dr. Akihiro Cho.
authors.affiliation: Division of Gastroenterological Surgery, Department of Surgery, Graduate School of Medicine, Osaka University, Suita, Japan. ydoki@gesurg.med.osaka-u.ac.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Doki