Ricardo Pietrobon1
, Ulrich Guller2
, Henrique Martins3
, Andreia P Menezes4
, Laurence D Higgins5
and Danny O Jacobs6 
1
Center for Excellence in Surgical Outcomes, Duke University Medical Center, Duke University, Durham, NC, USA
2
Center for Excellence in Surgical Outcomes, University Hospital Basel, Department of General Surgery and Surgical Research, Basel, Switzerland
3
Duke University Health System, Rio Claro/Sao Paulo, Brazil
4
Reliable International Research, Center for Excellence in Surgical Outcomes, Campina Grande do Sul/ Parana – Brazil
5
Department of Surgery, Duke University Medical Center, Durham, NC, USA
6
Department of Internal Medicine, University of North Carolina at Chapel Hill, NC, USA