Text and Data Mining valid from 2019-05-07
Received: 25 January 2019
Accepted: 15 April 2019
First Online: 7 May 2019
Ethics approval and consent to participate
: Waiver of ethics approval for this retrospective analysis was obtained from the ethics committee of the University Medical Center Freiburg. All patients had given written informed consent for scientific analysis of their data.
: Not applicable.
: The authors declare that they have no competing interests.
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