Koyama, Kansuke http://orcid.org/0000-0001-7415-4908
Katayama, Shinshu
Tonai, Ken
Shima, Jun
Koinuma, Toshitaka
Nunomiya, Shin
Article History
Received: 11 April 2019
Accepted: 31 July 2019
First Online: 19 August 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Research Ethics Committee of Jichi Medical University. Informed consent was waived based on the study’s retrospective, observational design, which preserves the confidentiality of personal information.
: Not applicable.
: The authors declare that they have no competing interests.