1. Department of Vascular Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
2. Department of Gastrointestinal Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
3. Department of Medical Record Management, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China