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

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%, = 0.610), stent-related AEs (4% vs. 15%, = 0.263), overall RBO rates (39% vs. 23%, = 0.168), cumulative incidence of RBO (hazard ratio, 2.24; 95% confidence interval, 0.95-5.25; = 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.