Received: 13 February 2017
Accepted: 5 January 2018
First Online: 24 January 2018
Ethics approval and consent to participate
: This study was approved by the Rennes University Hospital Ethics Committee (reference number 16.127) and performed in accordance with the Declaration of Helsinki guidelines (Additional file InternalRef removed).
: Not applicable.
: The authors declare that they have no competing interests.
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