Received: 19 November 2018
Accepted: 22 January 2019
First Online: 11 February 2019
Ethics approval and consent to participate
: Ethical approval to carry out the study was obtained a priori from the Okayama University Ethics Committee (Number 2034). Written consent from the patient to participation this study was obtained.
: Not applicable.
: The authors declare that they have no competing interests.
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