Pancreatoduodenectomy is the standard surgical operation for benign or malign pancreatic lesions. Pancreatic Fistula (PF) or Postpancreatectomy Acute Pancreatitis (PPAP) are the major complications associated with that type of surgery. We need to develop preventive measures for these complications, which requires a better understanding of their physiopathology. The aim of this prospective monocentric and observational study is to identify predictive biomarkers and/or risk factors for PF or PPAP using metabolomics. The Profiling of circulating metabolites is indeed an original and promising approach for this purpose. We will also investigate the patient's immune status and its association with the occurrence of post-surgical complications. Participants will be adult patients scheduled to undergo elective pancreaticoduodenectomy. Surgery and patient's management will be as usual. During surgery, a fragment (0.1-0.2 g) of non-tumoral pancreatic tissue will be removed and frozen at -80°C for metabolomic analysis. For immunological assessment, 4 blood samples will be collected (before surgery and then 7 days, 1 and 3 months after, blood sampling).