[1] Santa Casa Sao Paulo, Fac Ciencias Med, Dept Surg, Sao Paulo, SP, Brazil
[2] Univ Fed Pernambuco, Hosp Univ, Dept Surg, Recife, PE, Brazil
[3] Santa Casa Misericordia Sao Paulo, Dept Surg, Sao Paulo, SP, Brazil
[4] Univ Sao Paulo, Fac Med, Gastroenterol Dept, Sao Paulo, SP, Brazil
[5] Santa Casa Sao Paulo, Fac Ciencias Med, Sao Paulo, SP, Brazil
[6] Univ Estadual Londrina, Dept Surg, Digest Syst Surg, Londrina, PR, Brazil
[7] Univ Fed Parana, Fac Med Curitiba, Dept Surg, Curitiba, PR, Brazil