Text and Data Mining valid from 2019-04-01
Received: 29 January 2019
Accepted: 22 March 2019
First Online: 1 April 2019
Compliance with ethical standards
: Rindo Ishii, Ken Ohata and Eiji Sakai, Kentarou and Nakajima and Nobuyuki Matsuhashi declare that they have no conflict of interest.
: All procedures followed have been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.
: Informed consent was obtained from all patients for being included in the study.