Received: 6 October 2020
Accepted: 17 March 2021
First Online: 24 March 2021
: This study was conducted with the approval of the ethics committee of Yokohama City University (No. B180700036). The need for informed consent was waived due to the retrospective nature of this study. Instead, the study was displayed on the hospital’s website, and the opportunity to withdraw consent was given.
: Not applicable.
: The authors declare that they have no competing interests.