Received: 1 November 2019
Accepted: 24 May 2020
First Online: 28 May 2020
Ethics approval and consent to participate
: Our study protocol conformed to the Declaration of Helsinki and was approved by the Ethics Committee of the University Hospital Heidelberg vide letter no S-457/2013. Written informed consent to participate was obtained from all patients included in the study.
: Not applicable.
: The authors declare that they have no competing interests.