Fully covered metal biliary stents confer a higher risk of post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND Biliary fully-covered self-expanding metal stents (FCSEMS) are increasingly used over plastic or uncovered SEMS due to their long-term patency and removability. However, there is concern that transpapillary placement may lead to post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). AIM To assess the rates of PEP with and without the use of FCSEMS for both benign and malignant indications. METHODS We performed a multicenter retrospective cohort study involving three Australian tertiary referral centers. Consecutive adults who underwent ERCP for biliary indications between October 2016 and October 2019 were included. The primary endpoint was the rate of PEP. Secondary endpoints included severity of pancreatitis, other procedure- and stent-related adverse events occurring within 90 days. RESULTS A total of 3401 ERCPs were performed (54.2% female, mean age 62.9±18.6 years) with an overall PEP rate of 3.15%. On propensity-score matched analysis, FCSEMS was an independent predictor of PEP (odds ratio = 5.49, 95% confidence interval: 2.10-6.99; P = 0.001). FCSEMS had a higher rate of PEP (7.8%) compared with plastic stents (3.4%; P = 0.0015), and patients who did not receive any stents (2.4%; P = 0.001), but was non-significant when compared with uncovered self-expanding metal stents (3.9%; P = 0.12). The rate of PEP following FCSEMS decreased to 6.0% for malignant indications, and further to 3.9% for biliary obstruction due to pancreatic cancer, but did not reach statistical significance. CONCLUSION Biliary FCSEMS are associated with a higher risk of PEP compared to no stents or plastic stents, particularly for benign indications.