Received: 18 October 2018
Accepted: 23 April 2019
First Online: 15 May 2019
Ethics approval and consent to participate
: Data acquisition and analysis were done in accordance with ethical guidelines and approved by our institutional review board of the University of Freiburg (no. 89/09). Patients provided their written consent for participation. The trial was registered at the German Clinical Trials Register (no. 00000488), which also includes the follow-up.
: Not applicable.
: The authors declare that they have no competing interests.
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