Introduction : This study aimed to evaluate the long-term effect of clinically relevant postoperative pancreatic fistula (CRPOPF) on morphological and functional changes following pancreaticoduodenectomy (PD).

Methods : Among 760 patients who underwent PD from September 2003 to December 2016, 573 patients with postoperative 1-year follow-up data were selected. According to the ISGPS definition, the patients were classified into Non-CRPOPF (n=488) and CRPOPF groups (n=85). We compared (1) changes of pancreatic duct size and parenchymal cross-sectional area at the level of pancreatic transection by computed tomography and (2) endocrine function.

Results : At postoperative one year, atrophic change of parenchyma defined by >20% decrease of parenchymal cross-sectional area was similar between non-CRPOPF and CRPOPF groups (70.7% vs. 69.4%, P=0.811). In patients with preoperatively non-dilated duct, ductal dilatation after surgery was not different between the two groups (58.4% vs. 59.7%, P=0.672). However, in patients with preoperatively dilated duct, a decline in duct size after surgery was more frequently observed in the non-CRPOPF group than in the CRPOPF group (90.5% vs. 66.7%, P=0.009). Newly developed DM was not significantly different between the two groups (22% vs. 17.2%, P=0.326). In multivariate analysis, preoperative DM and initial bilirubin level <2.5 mg/dl were independent predictive factors for pancreatic parenchymal atrophy following PD.

Conclusions : POPF was not associated with parenchymal atrophy and worse endocrine function such as newly developed DM, although it negatively affected a reduction of preoperatively dilated pancreatic duct . These findings suggest that if we cope well with POPF complication, it will not deteriorate long-term functional outcomes.