Funding for this research was provided by:
Medizinische Hochschule Hannover (MHH)
Received: 21 February 2020
Accepted: 25 April 2020
First Online: 12 May 2020
Compliance with ethical guidelines
: C. Henkenberens, A.-K. Oehus, T. Derlin, F. Bengel, T.L. Ross, M.A. Kuczyk, S. Janssen, H. Christiansen, and C.A.J. von Klot declare that they have no competing interests.
: This retrospective analysis was approved by the local ethics committee.