[1] Hunan Normal Univ, Dept Gastrointestinal Surg, Affiliated Hengyang Hosp, Hengyang 421001, Hunan, Peoples R China
[2] Hengyang Cent Hosp, Hengyang 421001, Hunan, Peoples R China
[3] Univ South China, Affiliated Hosp 1, Hengyang Med Sch, Dept Hematol, Hengyang 421001, Hunan, Peoples R China
[4] Univ South China, Dept Gastrointestinal Surg, Nanhua Hosp, 336 Dongfeng South Rd, Hengyang 421002, Hunan, Peoples R China