[1] Catholic Univ Parana, Colorectal Surg Unit, Cajuru Univ Hosp, Rua Bruno Filgueira 369 Cj,1205, BR-80240220 Curitiba, Parana, Brazil
[2] Catholic Univ Parana, Dept Biostat, Rua Imaculada Conceicao 1155, BR-80215901 Curitiba, Parana, Brazil
[3] Campinas State Univ UNICAMP, Colorectal Surg Unit, Rua Tessalia Vieira Camargo 126, BR-13083887 Campinas, SP, Brazil