Adler, Christoph
Heller, Tobias
Schregel, Felix
Hagmann, Henning
Hellmich, Martin
Adler, Joana
Reuter, Hannes
Article History
Received: 22 December 2017
Accepted: 16 April 2018
First Online: 12 May 2018
Ethics approval and consent to participate
: The investigation was approved by the Ethic Committee of the University of Cologne and conforms to the principles outlined in the Declaration of Helsinki. Patients or their representatives were informed about the collection of their data and health information.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.