Article History
Received: 27 September 2017
Revised: 9 January 2018
Accepted: 19 January 2018
First Online: 1 February 2018
Compliance with ethical standards
:
: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge, or beliefs) in the subject matter or materials discussed in this manuscript.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee of St. Johannes Hospital in Dortmund, Germany, and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.