Takahashi, Yuki
Miyajima, Masahiro
Tada, Makoto
Maki, Ryunosuke
Mishina, Taijiro
Watanabe, Atsushi
Article History
Received: 1 April 2019
Accepted: 17 June 2019
First Online: 26 June 2019
Ethics approval and consent to participate
: This retrospective study was approved by our institutional review board (Sapporo Medical University Institutional Review Board clinical registration number: 302–167).
: The requirement to obtain informed consent was waived.
: The authors declare that they have no competing interests.