Cohort Study on Nutritional, Metabolic, and Volumetric Assessment After Pancreaticoduodenectomy

Pancreaticoduodenectomy (classic Whipple or pylorus-preserving) performed as part of standard clinical care for patients with periampullary malignant neoplasms. This procedure is not assigned by the study protocol, but is the exposure of interest. The study observes nutritional, metabolic, molecular, and imaging outcomes at baseline (preoperative), and at 3 and 6 months after hospital discharge.