Text and Data Mining valid from 2018-11-20
Received: 10 September 2018
Accepted: 31 October 2018
First Online: 20 November 2018
Ethics approval and consent to participate
: This retrospective study was approved by the Institutional Medical Ethics Committee (case number 2016/474), and the need for informed consent was waived. Consultation of the local objection registry verified that none of the selected patients had objected to use of their personal data for research purposes.
: 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.