Received: 23 January 2018
Accepted: 7 May 2018
First Online: 21 May 2018
Ethics approval and consent to participate
: This prospective study was approved by the ethics committee of Dokkyo Medical University Hospital (No. 22072) and the ethics committee of Dokkyo Medical University Koshigaya Hospital (No. 1409). This study was registered at the University Hospital Medical Information Network Center, Clinical Trials Registry (UMIN-CTR: No. UMIN000009599).
: Written informed consent for participation in the study was obtained from all patients.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.