Thick pancreas, dense duct branching, and limited fibrosis as risk factors for pancreatic fistula after distal pancreatectomy

The reported incidence of clinically-relevant postoperative pancreatic fistula (CR-POPF) after distal pancreatectomy (DP) ranges from 10% to 40%. Identification of risk factors for POPF may enable individualized modification of surgical techniques and postoperative management strategies. This study aimed to elucidate the clinico-histopathological characteristics associated with CR-POPF after DP. A total of 186 patients who underwent DP were investigated. Pancreatic thickness at the planned transection site was measured using preoperative computed tomography. Histopathological findings of the pancreatic stump, including branched pancreatic duct (BPD) density and fibrosis ratio, were assessed quantitatively using morphometric analysis. Risk factors for CR-POPF were analyzed. The incidence of CR-POPF was 33%. Factors associated with CR-POPF included pancreatic thickness ≥ 11.7 mm (odds ratio [OR] 3.736; p < 0.001), BPD density ≥ 2.5/100 mm² (OR 5.173; p < 0.001), and fibrosis ratio < 4.4% (OR 2.596; p = 0.041). Patients with pancreatic thickness ≥ 11.7 mm showed higher BPD density (2.5 vs. 1.8/100 mm²; p = 0.002) and lower fibrosis ratio (3.2% vs. 3.6%; p = 0.022). Greater pancreatic thickness, higher BPD density, and lower fibrosis ratio at the transection site were associated with CR-POPF after DP. As high BPD density and low fibrosis ratio were also associated with increased pancreatic thickness, these findings suggest that anatomical and histopathological pancreatic features may be jointly related to the risk of CR-POPF.