Text and Data Mining valid from 2019-02-01
Received: 23 May 2018
Accepted: 9 January 2019
First Online: 1 February 2019
Compliance with ethical standards
: On behalf of all authors, the corresponding author states there is no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Written informed consent has been obtained from all adult patients included in this study. In the case of minors, written informed consent from their guardians was obtained before enrolling them in the study.