Guide wire-assisted cannulation for the prevention of post-ERCP pancreatitis: a systematic review and meta-analysis.

BACKGROUND AND STUDY AIMS: Cannulation techniques are recognized to be important in causing post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, considerable controversy exists about the usefulness of the guide wire-assisted cannulation technique for the prevention of PEP. This systematic review of randomized controlled trials (RCTs) aimed to compare the guide wire-assisted cannulation technique with the contrast-assisted cannulation technique. METHODS: CENTRAL, MEDLINE, EMBASE, CINAHL, and abstracts from Digestive Disease Week and the United European Gastroenterology Week were searched up to February 2012 for RCTs comparing the guide wire-assisted ERCP cannulation technique with the conventional contrast-assisted ERCP cannulation technique. The risk of bias was assessed, and outcomes were pooled by meta-analysis (random-effects model). The primary outcome measure was PEP. Secondary outcome measures included severity of PEP, primary common bile duct (CBD) cannulation success, overall CBD cannulation success, precut sphincterotomy, and other ERCP-related complications. RESULTS: In total, 12 RCTs (3450 patients) were included. The guide wire-assisted cannulation technique significantly reduced PEP compared with the contrast-assisted cannulation technique (risk ratio [RR] 0.51, 95 % confidence interval [CI] 0.32 - 0.82). In addition, the guide wire-assisted cannulation technique was associated with greater primary cannulation success (RR 1.07, 95 %CI 1.00 - 1.15), fewer precut sphincterotomies (RR 0.75, 95 %CI 0.60 - 0.95), and no increase in other ERCP-related complications. Subgroup analyses indicated that this significant risk reduction in PEP with the guide wire-assisted cannulation technique existed only in "non-crossover" trials (RR 0.22, 95 %CI 0.12 - 0.42). The results were robust in sensitivity analyses. CONCLUSION: Compared with the contrast-assisted cannulation technique, the guide wire-assisted cannulation technique increases the primary cannulation rate and reduces the risk of PEP, and therefore appears to be the most appropriate first-line cannulation technique.