Article History
Received: 17 December 2017
Accepted: 27 February 2018
First Online: 19 March 2018
Compliance with ethical guidelines
:
: P. Bhogal serves as proctor and consultant for phenox GmbH, with moderate financial compensation. H. Henkes is a co-founder and shareholder of phenox GmbH. P. Lylyk, J. Chudyk and C. Bleise declare that they have no competing interests.
: The retrospective analysis and anonymous publication of the data presented herein was approved by the responsible Institutional Review Board.