Abstract
Evidence on pancreatic regeneration and functional recovery after pancreatectomy remains limited. This study investigates the correlation between volumetric changes and endocrine function of the remnant pancreas following pancreaticoduodenectomy (PD) and distal pancreatectomy (DP). We conducted a retrospective cohort study of patients who underwent PD or DP between January 2009 and December 2017 at a single institution. Pancreatic volume was assessed using contrast-enhanced computed tomography preoperatively and at 3 months, 1 year, and 2 years postoperatively. Endocrine function was evaluated using serial C-peptide index (CPI) measurements. A total of 90 PD and 45 DP patients were analyzed. Compared with initial residual volume, remnant pancreas in PD progressively declined (80.79%, 68.67%, and 65.34% at 3 months, 1 year, and 2 years; β = -11.85, p < 0.001), whereas DP patients demonstrated hypertrophic changes (106.25%, 106.62%, and 110.43%; β = 2.97, p = 0.019). New-onset diabetes occurred in 22.7% of PD and 33.3% of DP patients. Postoperative pancreatic duct dilatation was associated with greater atrophy in PD (β = -9.82, p = 0.027). Despite superior volume preservation in DP, PD demonstrated better endocrine functional recovery (CPI/volume ratio: β = 126.9, p < 0.001), corresponding with lower new-onset diabetes incidence. Pancreatic volume and endocrine function recover independently after pancreatectomy. Despite greater volume preservation, DP patients experience more endocrine dysfunction than PD due to higher islet density in the distal pancreas.