Received: 18 October 2018
Accepted: 17 January 2019
First Online: 7 February 2019
Ethics approval and consent to participate
: The local Ethics Committee approved the study with no requirements (Ref. No. 57_17 B; University of Erlangen-Nuremberg). All patients were informed regarding the purpose, benefits and risks of the investigation prior to signing an institutionally approved informed consent form to participate in the study.
: Not applicable
: The authors declare that they have no competing interests.
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