Received: 14 November 2018
Accepted: 30 January 2019
First Online: 24 April 2019
Ethics approval and consent to participate
: Ethical approval was given by AOU Parma Ethical Committee, Prot. N. 44,708 of 2017.This is a retrospective study and no consent to participate to study was required.
: Not applicable.
: The authors declare that they have no competing interests.
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