Text and Data Mining valid from 2018-03-15
Received: 28 December 2017
Accepted: 8 March 2018
First Online: 15 March 2018
Ethics approval and consent to participate
: Written informed consent was obtained from all study patients. The study was carried out according to the principles of the declaration of Helsinki and was approved by the medical ethics committee II of the Faculty of Medicine Mannheim, University of Heidelberg, Germany.
: 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.