This observational study was conducted in patients undergoing elective pancreaticoduodenectomy or distal pancreatectomy. It mainly answers the following two main questions: 1. What are the risk factors for clinically relevant postoperative pancreatic fistula in different pancreatic surgeries? 2. What is the correlation between perioperative blood and interstitial fluid glucose level and clinically relevant postoperative pancreatic fistula in different pancreatic surgeries？ Participants were not required to perform additional research work other than the usual postoperative follow-up within 30 days after surgery. No control group was set in this study, and no additional clinical intervention was performed.