Received: 26 January 2020
Accepted: 18 May 2020
First Online: 21 May 2020
Ethics approval and consent to participate
: All participants received prior information about the study before providing their written informed consent in accordance with the declaration of Helsinki. The study was approved by the ethical committee of Akita University Hospital (registration number 1970).
: Written informed consent was obtained from the patients for publication of this research and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.
: All authors declare that they have no competing interests.