Received: 27 March 2019
Accepted: 22 July 2019
First Online: 29 July 2019
Ethics approval and consent to participate
: The study was performed in accordance with the ethics standards at the Technical University of Munich (TUM) (ethical vote: 385/18 s).Name of committee: Ethikkommission der Technischen Universität München.Due to BayKrG: Art. 27 (Paragraph 4), the IRB has found that consent to participate in this unpersonalized retrospective analysis was not required.
: Not applicable.
: The authors declare that they have no competing interests.