Received: 7 February 2019
Accepted: 19 March 2020
First Online: 27 March 2020
Ethics approval and consent to participate
: Heidelberg university institutional review board (Ethics Committee Heidelberg) approved this study. Application number: S-572/2015. A written consent was obtained by all patients who participated in this study.
: Not applicable
: The authors declare that they have no competing interests.