Immunoparalysis After Pancreaticoduodenectomy

Inclusion Criteria: * Any patient undergoing a Pancreaticoduodenectomy in one of the four participating centers for a benign or malignant tumor of the pancreatic head Exclusion Criteria: * Age \< 18 years * Pregnant, postpartum, or breastfeeding women * Indication other than tumor-related (e.g., chronic pancreatitis) * Patient with an infectious syndrome at the time of inclusion * Preoperative immunosuppression * Immunosuppressive disease other than cancer: * Congenital or acquired immune deficiency * Functional hyposplenism or asplenia, patient under long-term antibiotic prophylaxis for this reason * Patient with HIV (and CD4 \< cells/mm³) * Aplasia defined by circulating neutrophil count \< 500 cells/mm³ * Immunosuppressive treatment other than chemotherapy : Biotherapy, Corticosteroid therapy \>10 mg/day or cumulative dose \>700 mg prednisolone equivalent : Patient expected to receive immunosuppressive treatment within the first 7 postoperative days * Individuals deprived of liberty by judicial or administrative decisio * Adults under legal protection (guardianship or curatorship) * Individuals not affiliated with a social security scheme or an equivalent coverage * Refusal to participate in the study