1. Department of General Surgery, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
2. Department of General Surgery, Drum Tower Clinical Medical College of Nanjing Medical University, Nanjing, Jiangsu 211166, P.R. China
3. Department of General Surgery, Drum Tower Clinical Medical College of Nanjing University, Nanjing, Jiangsu 210093, P.R. China