Outcomes of 6‐mm diameter fully covered self‐expandable metal stents for preoperative biliary drainage in pancreatic cancer

Abstract Background 10‐mm self‐expandable metal stents (SEMSs) are commonly used for preoperative biliary drainage in pancreatic cancer. However, smaller diameter SEMSs have attracted attention with the attempt to reduce stent‐related adverse events (AEs). Methods We retrospectively analyzed consecutive borderline resectable pancreatic cancer patients who underwent neoadjuvant therapy and fully covered SEMS (FCSEMS) placement from April 2015 to May 2023. The primary outcome was stent‐related non‐event rate (NER), which was defined as the rate of completion of surgery without developing any preoperative events (recurrent biliary obstruction [RBO] or stent‐related AEs). Secondary outcomes included stent‐related AEs, causes of RBO, and cumulative incidence of RBO. Risk factors for pancreatitis, RBO, and stent migration were also examined. Results A total of 76 patients were included (6‐mm group: 23; 10‐mm group: 53). Stent‐related NER (57% vs. 64%, p = 0.610), stent‐related AEs (4% vs. 15%, p = 0.263), overall RBO rates (39% vs. 23%, p = 0.168), cumulative incidence of RBO (hazard ratio, 2.24; 95% confidence interval, 0.95–5.25; p = 0.065) were not significantly different between the two groups. Tumor involvement of the pancreatic duct was identified as a risk‐reducing factor for pancreatitis, while an FCSEMS diameter of 6 mm was not identified as a risk factor for RBO and stent migration. Conclusions Stent‐related NER was not significantly affected by FCSEMS diameter. Further studies are needed to confirm the usefulness of 6‐mm diameter FCSEMS for preoperative biliary drainage in patients with borderline resectable pancreatic cancer.