Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) has been a well-recognized complication with significant morbidity and even mortality. A variety of possible mechanisms has been suggested in the occurrence of pancreatitis, but papillary edema caused by manipulations during cannulation or endoscopic treatment has received the most attention. The papillary edema may cause temporary outflow obstruction of pancreatic juice, and then increase ductal pressure, resulting in the occurrence of pancreatitis. Topical application of epinephrine on the papilla may reduce papillary edema. Moreover, it is reported that epinephrine sprayed on the papilla may be effective to prevent PEP. However, it is still unclear that epinephrine sprayed on the papilla can prevent acute pancreatitis after endoscopic retrograde cholangiopancreatography. We therefore designed a prospective randomized trial to determine whether epinephrine sprayed on the papilla prevent PEP after ERCP.

Between July 2016 and December 2017, 670 consecutive patients older than 18 years who are scheduled to undergo diagnostic or therapeutic ERCP at the Anhui Provincial Hospital will be recruited for the study. Patients were randomized using opaque, sealed envelopes containing random numbers assigning them to undergo a spray of epinephrine (epinephrine group) or saline (control group) on the major papilla. A two proportion equality test will be conducted to explore whether incidence rates are different. Descriptive statistics including number (N), mean, median, standard deviation, minimum and maximum, will be produced for all continuous variables. Frequency tables of number (N) and percentage of subjects will be produced for all categorical variables.

Inclusion Criteria:

1. Males and females, age > 18 years.
2. Normal amylase level before undergoing ERCP.
3. Signed inform consent form and agreed to follow-up on time.

Exclusion Criteria:

1. Pregnancy or history of allergy to epinephrine.
2. Medical or psychological condition that would not permit the patient to complete the study or sign the informed consent.
3. Patients involved in other study within 60 days.
4. Billroth II or Roux-en-Y anatomy
5. Acute pancreatitis.
6. All contraindications to epinephrine.