5-Fr vs3-Fr pancreatic stents for the prevention of post-ERCP pancreatitis in high-risk patients: A systematic review and network meta-analysis

Background and study aims: Placement of a pancreatic stent is recommended for the prevention of pancreatitis after endoscopic retrograde cholangiopancreatitis (ERCP) among high-risk patients. However, it is not known whether there is a particular feature of the pancreatic stent that is associated with a lower incidence of post-ERCP pancreatitis (PEP). This systematic review and network meta-analysis (NMA) aimed to examine whether a particular feature of pancreatic stents is associated with lower incidence of PEP. Patients and methods: The MEDLINE, Embase, and Cochrane Library databases were searched for randomized controlled trials (RCTs) that evaluated the efficacy of pancreatic stents in the prevention of PEP from September 1993 to June 2013. Trials that reported the incidence of PEP in high-risk patients randomized to one vs. another type of pancreatic stent or vs. no stent at all were included in the analysis. Results: Among the 1377 citations identified from the database searches, 6 RCTs involving 561 patients were included. Three RCTs evaluated 5-Fr straight, flanged pancreatic stents, two RCTs evaluated 5-Fr single-pigtail, unflanged stents, and three RCTs evaluated 3-Fr single-pigtail, unflanged stents. The probability of being ranked the best was 50.3% (SD=0.5, Markov chain error=0.003) for 5-Fr single-pigtail, unflanged pancreatic stents, 46.5% for 5-Fr straight, flanged stents, and 3.1% for 3-Fr single-pigtail, unflanged stents. Conclusion: The 5-Fr pancreatic stent is superior to the 3-Fr pancreatic stent for the prevention of PEP in high-risk patients. The 5-Fr single-pigtail, unflanged pancreatic stent and 5-Fr straight, flanged pancreatic stent performed similarly and both performed better than the 3-Fr pancreatic stent in preventing PEP, suggesting that stent diameter is more important for the prevention of PEP than type of stent or the presence of flanges.