Frequency, Severity, and Risk Factors for Acute Pancreatitis After Percutaneous Transhepatic Biliary Stent Placement Across the Papilla of Vater.

PURPOSE: To clarify the frequency, severity, and risk factors for acute pancreatitis after percutaneous biliary stent placement across the papilla of Vater for malignant biliary obstruction.

MATERIALS AND METHODS: This retrospective study included 95 patients who underwent percutaneous biliary metallic stent placement (64 [67.4%] bare stents and 31 [32.6%] covered stents) across the papilla of Vater for malignant biliary obstruction between January 2010 and December 2012. The incidence of acute pancreatitis (Atlanta classification of acute pancreatitis) and its severity (Common Terminology Criteria for Adverse Events, version 4) were reviewed. Additionally, the characteristics of the patients and biliary stents, and the computed tomography findings of the pancreas were evaluated.

RESULTS: Grade 3 acute pancreatitis was observed in 23 patients (24.2%); acute pancreatitis of grade 4 or higher was not observed. The incidence of acute pancreatitis was lower in patients with atrophic pancreas than in those with non-atrophic pancreas (7.5 vs. 36.4%, p = 0.004). It was also lower in patients with main pancreatic duct (MPD) obstruction than in those without MPD obstruction (12.5 vs. 36.2%, p = 0.026). There was no difference in the incidence of acute pancreatitis between bare and covered stents.

CONCLUSION: Percutaneous biliary stent placement across the papilla of Vater for malignant biliary stricture caused acute pancreatitis requiring medication in 24.2% of patients. Atrophy of the pancreas and the presence of a dilated MPD may be associated with a decreased risk of acute pancreatitis.

LEVEL OF EVIDENCE: Level 4, Case Series.