Received: 17 May 2019
Accepted: 28 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: Ethical approval for the study design was obtained from the Institutional Ethics Review Committee of the University of Tsukuba. Written informed consent was obtained from all individual participants included in the study.
: Written informed consent for publication was obtained from the patients included in this study.
: The authors declare that they have no competing interests.