Funding for this research was provided by:
Text and Data Mining valid from 2018-06-25
Received: 13 March 2018
Accepted: 19 June 2018
First Online: 25 June 2018
Ethics approval and consent to participate
: Prior to this study, the local ethics committee (Ethics Committee of the Friedrich-Alexander University Erlangen-Nürnberg) confirmed that no further patients consent and institutional ethical approval were required. This decision was based on the retrospective, descriptive and anonymous study design and the fully closed patient files.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.