Received: 3 May 2019
Accepted: 22 July 2019
First Online: 1 August 2019
Ethics approval and consent to participate
: This study was reviewed and approved by the local Ethics Committee of the University of Heidelberg and was registered under S-460/2016. All methods were performed in accordance with the relevant guidelines and regulations.
: Consent for the collection of data was obtained from the patients or legal guardians.
: The authors declare that they have no competing interests.