Department of General Surgery, Research Institute of Pancreatic Disease, Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China. wawljwalj@163.com. Department of Hepatobiliary Surgery, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, China. wawljwalj@163.com. Department of General Surgery, Research Institute of Pancreatic Disease, Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China. Department of Hepatobiliary Surgery, Union Hospital, Fujian Medical University, Fuzhou, China. Department of General Surgery, Research Institute of Pancreatic Disease, Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China. zhanxi80@hotmail.com. Department of General Surgery, Research Institute of Pancreatic Disease and Shanghai Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. zhanxi80@hotmail.com. Department of General Surgery, Research Institute of Pancreatic Disease, Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China. chhpeng@yeah.net. Department of General Surgery, Research Institute of Pancreatic Disease and Shanghai Institute of Digestive Surgery, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Road, Shanghai, 200025, China. chhpeng@yeah.net.