1. Department of Gastrointestinal and Thyroid Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan�410013, P.R.�China
2. Department of Emergency Medicine, The Third Xiangya Hospital of Central South University, Changsha, Hunan�410013, P.R. China
3. Department of Oncological Surgery, Traditional Chinese Medicine of Shaoyang Hospital, Shaoyang, Hunan�422001, P.R.�China
4. Department of General Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan�410013, P.R. China