Received: 21 October 2017
Accepted: 19 February 2018
First Online: 1 March 2018
Ethics approval and consent to participate
: The present study was approved by the institutional review board of the Klinikum Stuttgart and is in compliance with the Declaration of Helsinki. The study was designed as an observational retrospective analysis and therefore did not influence the therapy in any way.
: The present manuscript does not contain any individual’s data in any form.
: The authors declare that they have no competing interests.
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