Spray of peppermint oil on papilla shortens the cannulation time of endoscopic retrograde cholangiopancreatography (ERCP): a randomized study

Objective: Endoscopic retrograde cholangiopancreatography (ERCP) is widely used for the diagnosis and treatment of pancreatobiliary disease but requires a high level of endoscopic techniques, especially cannulation of the common bile duct (CBD). Peppermint oil has been reported to inhibit the contraction of smooth muscle. We hypothesized that spray of peppermint oil on papilla can shorten the cannulation time of ERCP. Methods: 160 patients suspected of pancreatobiliary disease were randomly assigned to Peppermint oil group (group PO, n = 80) and Normal saline group (group NS, n = 80). After insertion of the duodenoscope and find the duodenal papilla, 20 mL of 1.6% peppermint oil solution (group PO) or Normal saline (group NS) was sprayed on the papilla by syringe via the working channel. The Deep CBD cannulation time, success rate of biliary cannulation and the incidence rate of adverse events were assessed. Results: The average cannulation time for the first 5 minutes was 189.7 (2-300) seconds in group PO and 237.8 (2-300) seconds in group NS (P = 0.03). The final success rate of biliary cannulation was 98.8% in group PO and 100.0% in group NS. The incidence rate of post-ERCP pancreatitis was 2.5% (2/80) in group PO and 6.3% (5/80) in group NS (P = 0.44). The mean amylase concentration was 177.4 (range 36-1067) IU/L in group PO and 267.5 (range 42-1733) IU/L in group NS (P = 0.04). Conclusion: Peppermint oil helps us to cannulate the papilla, shorten the time of cannulation, and reduce the incidence of hyperamylasemia after ERCP.