[1] Hosp Sao Lucas PUCRS, Thorac Surg, Porto Alegre, RS, Brazil
[2] Univ Sao Paulo, Med Sch, Thorac Surg, Sao Paulo, Brazil
[3] Univ Fed Rio Grande do Sul, Stat, Porto Alegre, RS, Brazil
[4] Hosp Santa Isabel, Salvador, BA, Brazil
[5] Hosp Pavilhao Pereira Filho, Porto Alegre, RS, Brazil
[6] Hosp Base Dist Fed, Brasilia, DF, Brazil
[7] Univ Caxias Do Sul, Caxias Do Sul, Brazil