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

Abstract

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 < 0.001) were significant risk factors for pancreatitis.

Conclusions: SEMSs with high axial force and an etiology of MBO other than pancreatic cancer were strongly associated with a high incidence of pancreatitis following transpapillary SEMS placement in patients with distal MBO.