Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (INST 335/454-1)
Received: 14 July 2020
Accepted: 13 October 2020
First Online: 17 December 2020
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This retrospective study was approved by the institutional ethics review board (EA1/060/16), and the institutional review board waived the requirement for informed consent for this retrospective analysis.
: All authors give their consent.
: The authors declare that they have no competing interests.