[1] Hosp Especialidades 14 Adolfo Ruiz Cortines, Inst Mexicano Seguro Social IMSS, Unidad Med Alta Especialidad UMAE, Dept Organ Transplantat, Veracruz, Mexico
[2] Hosp Especialidades 14 Adolfo Ruiz Cortines, Dept Gen Surg, UMAE, IMSS, Veracruz, Mexico
[3] Hosp Especialidades 14 Adolfo Ruiz Cortines, UMAE, Dept Res, Veracruz, Mexico
[4] Inst Nacl Cancerol, Gastrointestinal Tumors, Mexico City, DF, Mexico
[5] Hosp Especialidades Dr Antonio Fraga Mouret, Ctr Med Nacl La Raza, Hepatopancreatobiliary Clin, Gen Surg Serv,IMSS, Mexico City, DF, Mexico
[6] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Surg, Mexico City, DF, Mexico