Inflammation and fibrosis at pancreatic resection margin and their role in post-operative pancreatic fistula development after pancreaticoduodenectomy: a pilot study from a single institution.

Background/objectives: Postoperative pancreatic fistula (POPF) is a major complication after pancreaticoduodenectomy (PD), with significant impact on outcomes. While the absence of pancreatic fibrosis is a known risk factor, its intraoperative assessment is often subjective. Moreover, the potential protective role of chronic inflammation at the pancreatic resection margin (PRM) has not been fully explored. This study aimed to evaluate the histological presence of fibrosis and chronic lymphomononuclear inflammatory infiltrate (CLII) at the PRM as predictors of POPF and clinically relevant POPF (CR-POPF), and to assess their intraoperative feasibility via frozen sections. Materials and methods: A retrospective analysis was performed on 141 patients who underwent PD (2014-2022). Intraoperative frozen sections of the PRM were reviewed for fibrosis and CLII using standardized semi-quantitative grading. Univariate and multivariate analyses identified predictors of POPF and CR-POPF. Results: POPF and CR-POPF occurred in 42.5 % and 22.7 % of patients, respectively. Absence of fibrosis and CLII were independently associated with increased risk of POPF (OR 7.51 and 4.30; Conclusion: The absence of fibrosis and CLII at the PRM strongly predicts POPF and CR-POPF. Their intraoperative evaluation via frozen sections is feasible and may support tailored surgical strategies, especially in minimally invasive PD.