The influence of fully covered metal stenting on the risk of post-endoscopic retrograde cholangiopancreatography pancreatitis - A large multicenter study.

BACKGROUND AND AIMS Fully covered self-expandable metal stents (FCSEMSs) have been increasingly used in the management of benign or malignant biliary disorders. However, the risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) with transpapillary placement of the FCSEMS remains controversial. This study therefore aimed to investigate the risk of PEP in patients who received FCSEMS implantation. METHODS In total, 602 patients who underwent endoscopic transpapillary FCSEMS placement at 5 Chinese medical centers, between 2011 and 2018, were included in this retrospective study. Patients who were younger than 18 years old and with stent placement above the papilla were excluded from the study. PEP and the risk factors were reviewed. RESULTS PEP occurred in 56 (9.3%) patients, and 8 (1.3%) of them experienced moderate to severe PEP. The incidence of PEP rose to 14.6% (51/349) when patients had no pancreatic duct (PD) dilation, and even to 18.6% if no prophylactic approaches were adopted. Prophylactic PD stenting showed better efficacy in reducing the incidence of PEP compared to rectal use of indomethacin (3.5% vs. 10.8%, P=0.023). Multivariate logistic regression revealed that difficult cannulation (OR 2.837, 95%CI 1.245-6.465, P=0.013), PD dilation (OR 0.145, 95%CI 0.05-0.422, P<0.001), and PD stenting (OR 0.247, 95%CI 0.089-0.686, P=0.007) were significantly associated with PEP risk. Post-procedure cholecystitis was found in 4.0% of patients. CONCLUSION The risk of post-procedure pancreatitis is modestly increased in patients receiving transpapillary FCSEMS placement, particularly when there is absence of pancreatic duct dilation. Thus, prophylactic pancreatic stenting is recommended in such a condition.