[1] Hosp Univ Vall dHebron, Dept Surg, Colorectal Unit, E-08035 Barcelona, Spain
[2] Univ Autonoma Barcelona, Hosp Univ Mar, Dept Surg, Colorectal Unit, E-08193 Barcelona, Spain
[3] Complejo Hosp Navarra, Dept Surg, Colorectal Unit, Pamplona, Spain
[4] Univ Publ Navarra, Dept Hlth Sci, Pamplona, Spain