Received: 15 February 2021
Accepted: 13 April 2021
First Online: 3 May 2021
: The present study was approved by the institutional review board of University of Tsukuba Hospital and written informed consent was obtained from all patients. All procedures were performed in accordance with relevant guidelines.
: Written informed consent was obtained from all patients for publication of this study.
: The authors declare that they have no competing interests.