Guidewire versus conventional contrast cannulation of the common bile duct for the prevention of post-ERCP pancreatitis: a systematic review and meta-analysis.Cheung J, Tsoi KK, Quan WL, Lau JY, Sung JJ. Gastrointest Endosc. 2009 Dec;70(6):1211-9. BACKGROUND: The use of a guidewire (GW) for cannulation of the bile duct during ERCP may prevent post-ERCP pancreatitis (PEP). OBJECTIVES: A systematic review and meta-analysis of GW-guided versus conventional contrast (CC)-guided bile duct cannulation for the prevention PEP. DESIGN: A November 2008 search of gray literature, databases, reference lists, and meeting abstracts was conducted for randomized, controlled trials comparing GW and CC. Two independent reviewers extracted the data. The outcomes included PEP, primary cannulation success, and other adverse events. RESULTS: From 2132 citations, 7 randomized, controlled trials (5 noncrossover trials and 2 crossover trials) were included. Among noncrossover trials only, there was significant reduction in PEP when using a GW (3.2%) compared with CC (8.7%) (relative risk [RR] 0.38; 95% CI, 0.19-0.76). Subgroup analysis showed a significantly lower occurrence of PEP after GW entry versus CC injection of the pancreatic duct (1.1% vs 9.5%; RR 0.19; 95% CI, 0.06-0.58). Among patients with a precut sphincterotomy from a failed primary cannulation, there was less PEP with GW cannulation compared with CC (2.4% vs 21.7%; RR 0.21; 95% CI, 0.04-1.04). The other adverse event rates were comparable between GW and CC groups (2% vs 2%; RR 1.05; 95% CI, 0.39-2.83). Primary cannulation success was significantly greater with GW use compared with CC (89% vs 78%; RR 1.19; 95% CI, 1.05-1.35). CONCLUSION: ERCP GW cannulation reduces the risk of PEP compared with the use of CC. GW cannulation is associated with a higher cannulation success rate and less PEP after pancreatic duct entry.