1. Department of General Surgery, Mianyang Hospital of Traditional Chinese Medicine, Mianyang, Sichuan 621000, P.R. China
2. Department of Pathology, Mianyang Hospital of Traditional Chinese Medicine, Mianyang, Sichuan 621000, P.R. China
3. Department of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China