Article History
Received: 13 September 2020
Revised: 16 December 2020
Accepted: 31 December 2020
First Online: 26 January 2021
Compliance with ethical standards
:
: The scientific guarantor of this publication is Per Sandström, Department of Surgery and Clinical and Experimental Medicine, University Hospital of Linköping, Sweden.
: The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.
: One of the authors has significant statistical expertise.
: Written informed consent was not required for this study because this is a systematic review and meta-analysis of publicly available published data. Also included is a retrospective analysis of our center data which is collected routinely at our institution in an encrypted format with patients giving consent at the time for it to be used for education and research in an anonymized fashion.
: Institutional Review Board approval was not required because this is a systematic review and meta-analysis of already published publicly available data. Also included is a retrospective analysis of our center data which is collected routinely at our institution in an encrypted format with patients giving consent at the time for it to be used for education and research in an anonymized fashion. Review board approval is not required at your center for such studies.
: • Retrospective• Observational• Performed at one institution