Katayama, Shinshu http://orcid.org/0000-0002-6078-5052
Koyama, Kansuke
Goto, Yuya
Koinuma, Toshitaka
Tonai, Ken
Shima, Jun
Wada, Masahiko
Nunomiya, Shin
Article History
Received: 7 October 2017
Accepted: 12 April 2018
First Online: 2 May 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Jichi Medical University (Tochigi, Japan) (approval number: 16–116). The need for informed consent was waived on the basis of the study’s retrospective observational design preserving the confidentiality of personal information.
: The authors declare that they have no competing interests.
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