Received: 18 December 2018
Accepted: 2 January 2019
First Online: 12 January 2019
Ethics approval and consent to participate
: A written consent was received from all patients or their legal representatives for the use of their data in this study. Ethics approval was received from the Board of Review at the Witten / Herdecke University.
: Consent for publication was granted by all patients included in the study.
: The authors declare that they have no competing interests.
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