Pancreatic volume and endocrine function changes following pancreaticoduodenectomy for peri-ampullary neoplasms: A retrospective single-center study utilizing pancreas volumetry.

Backgrounds/Aims: We evaluated long-term pancreatic functional outcomes, including pancreatic volumetry after pancreaticoduodenectomy (PD) for peri-ampullary neoplasm. Methods: We retrospectively reviewed 353 patients with a 12-month follow-up who underwent elective pancreaticoduodenectomies for peri-ampullary neoplasms at a single university hospital between January 2011 and December 2020. Perioperative and postoperative outcomes, long-term pancreatic endocrine functions, and pancreatic volume changes 12 month postoperatively were evaluated. Results: The mean age was 65.4 years, and the sex ratio was 1.38. The patients with prediagnosed diabetes mellitus (DM) comprised 31.4%. The peri-ampullary neoplasm origins were: the pancreas (49.0%), common bile duct (27.2%), ampulla of Vater (18.4%), and duodenum (5.4%). The 1-week, and 3-, 6-, and 12-month postoperative proportions of patients with DM diagnosed before surgery combined with new-onset postoperative DM were 39.7%, 42.8%, 43.9%, and 49.6%, respectively. The preoperative and postoperative 1-week, and 3-, 6-, and 12-month mean pancreatic volumes were 82.3, 38.7, 28.1, 24.9, and 25.5 mL, respectively. Univariate risk factor analyses for new-onset DM after PD observed no significant difference between the 'No DM after PD' and 'New-onset DM after PD' groups. Conclusions: Following PD for peri-ampullary neoplasms, pancreatic endocrine functions and volumes continued to decrease for a minimum of 12 months. The current study did not identify any causal relationship between pancreatic endocrine dysfunction and pancreatic atrophy following PD.