Conflict of interest

Yuka Hayashi, Hikaru Otani, Hideyuki Mishima, and Ako Itoh declare that they have no conflicts of interest.

Ethical approval

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki of 1964 and later versions.

Informed consent

Informed consent was obtained from all patients for being included in the study.