Risk factors for pancreatitis following transpapillary self-expandable metal stent placement

Background Pancreatitis is one of complications after self-expandable metal stent (SEMS) placement. The purpose of this study was to evaluate risk factors for pancreatitis after endoscopic SEMS placement for malignant biliary obstruction (MBO). Methods We retrospectively reviewed 370 consecutive patients who underwent initial transpapillary SEMS placement for biliary decompression. The characteristics of inserted SEMSs were classified according to axial and radial force. Results Pancreatitis following SEMS insertion was observed in 22 patients (6%). All of them were mild according to consensus criteria. Univariate analysis indicated that injections of contrast into the pancreatic duct (frequency of pancreatitis, 10.3%), the placement of an SEMS with high axial force (8.3%), and nonpancreatic cancer (16.1%) significantly contributed to the development of pancreatitis, whereas female gender, a younger age, a covered SEMS, and a SEMS with high radial force or without a biliary sphincterotomy did not. In a multivariate risk model, SEMSs with high axial force (odds ratio [OR], 3.69; p = 0.022) and nonpancreatic cancer (OR, 5.52; p