Funding for this research was provided by:
Japan Society for the Promotion of Science (#17K17045)
Received: 7 April 2020
Accepted: 20 July 2020
First Online: 29 July 2020
Ethics approval and consent to participate
: This study was conducted in accordance with the principles of the 1964 Declaration of Helsinki and its later amendments. The Institutional Review Board of the Tokyo Medical and Dental University approved this study (#788). The requirement for informed consent from each patient was waived given the retrospective design of the study, the use of anonymized patient, and hospital data.
: Not applicable
: The authors declare that they have no competing interests.