Received: 29 April 2020
Accepted: 24 August 2020
First Online: 28 August 2020
Ethics approval and consent to participate
: All patients provided informed consent for the procedure and provided written informed consent for institutional storage of their personal data in a scientific database. The medical ethics committee of the Hokkaido University School of Medicine approved the present study’s retrospective protocol (#019–0346), which was registered at ExternalRef removed (#5246).
: The requirement for patient consent for publication was waived based on the use of de-identified data.
: The authors declare no conflicts of interest in association with the present study.