Footnotes

• Contributors YY and YN drafted the manuscript; YY, YN, MO, YO, KO, KI and HN were in charge of the patient and collected the data; KT collected the data; and FO critically revised the manuscript. All authors approved the final version.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Obtained.

• Provenance and peer review Not commissioned; externally peer reviewed.