Sato, Seijiro
Shimizu, Yuki
Goto, Tatsuya
Kitahara, Akihiko
Koike, Terumoto
Ishikawa, Hiroyuki
Watanabe, Takehiro
Tsuchida, Masanori
Article History
Received: 23 February 2018
Accepted: 1 August 2018
First Online: 10 August 2018
Ethics approval and consent to participate
: The study was approved by the ethics committee of the Niigata University (No. 2302), and the requirement for informed consent was waived because the study was a retrospective review.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.