Risk of post-ERCP pancreatitis with placement of self-expandable metallic stents

Abstract

There are conflicting data on the risk of post-ERCP pancreatitis (PEP) related to self-expandable metallic stents (SEMSs). To compare rates of PEP in patients who undergo biliary drainage with SEMSs or polyethylene stents (PSs). Retrospective, cohort study. Tertiary-care medical center. This study involved patients undergoing ERCP for malignant biliary obstruction between January 2005 and October 2008. First-time placement of a SEMS or PS for biliary decompression. Early post-ERCP complications, particularly PEP. We identified 544 eligible patients, 248 SEMSs (102 covered), and 296 PSs. The etiology of malignant biliary obstruction was similar between groups, with 55% from pancreatic cancer. The frequency of PEP was significantly higher in the SEMS group (7.3%) versus the PS group (1.3%) (OR 5.7 [95% CI, 1.9-17.1]). On univariate analysis, patient age of <40 years, a history of PEP, and at least 1 pancreatic duct injection were also significant predictors of PEP, whereas female sex and having pancreatic cancer were not. When significant variables were added to a multiple-predictor regression model, the odds of PEP from SEMS placement increased to 6.8 (95% CI, 2.2, 21.4). However, the frequency of PEP was similar between covered (6.9%) and uncovered (7.5%) SEMSs (OR 0.9 [CI, 0.3-2.4]). Purported SEMS-specific risk factors, including the use of cSEMSs, overlapping SEMSs, or having a biliary sphincterotomy were not found to be significant contributors to the higher risk. Retrospective design. After we controlled for confounding variables, the frequency of PEP was significantly higher with placement of a SEMS compared with a PS. Rates of PEP were comparable with use of covered and uncovered SEMSs.