Background: Pancreatitis is the most frequent complication of endoscopic retrograde cholangiopancreatography (ERCP), accounting for substantial morbidity, occasional mortality, and increased health care expenditures. Until recently, the only effective method of preventing post-ERCP pancreatitis (PEP) had been prophylactic pancreatic stent placement (PSP), an intervention that is costly, time consuming, technically challenging, and potentially dangerous. The investigators recently reported the results of a large randomized controlled trial demonstrating that rectal indomethacin, a non-steroidal anti-inflammatory drug, reduced the risk of pancreatitis after ERCP in high-risk patients, most of whom (>80%) had received a pancreatic stent. Secondary analysis of this RCT suggested that subjects who received indomethacin alone were less likely to develop PEP than those who received a pancreatic stent alone or the combination of indomethacin and stent, even after adjusting for underlying differences in subject risk. If indomethacin were to obviate the need for PSP, major clinical and cost benefits in ERCP practice could be realized.

Objective: To assess whether rectal indomethacin alone is non-inferior to the combination of rectal indomethacin and prophylactic pancreatic stent placement for preventing post-ERCP pancreatitis in high-risk cases.

Methods: Comparative effectiveness multi-center non-inferiority trial of rectal indomethacin alone vs. the combination of rectal indomethacin and prophylactic pancreatic stent placement for the prevention of post-ERCP pancreatitis in high-risk patients. One thousand four hundred and thirty subjects at elevated risk for PEP who would normally receive a pancreatic stent for prophylaxis will be randomized to indomethacin alone or the combination of indomethacin and PSP. The proportion of patients developing PEP and moderate-severe PEP will be compared. In addition, the investigators will establish a quality-assured central repository of biological specimens obtained from study participants, permitting future translational research elucidating the molecular and genetic mechanisms of PEP, as well as the mechanisms by which non-steroidal anti-inflammatory drugs prevent this complication.

The purpose of the SVI study is to determine whether or not rectal indomethacin has no important loss of efficacy as compared to the combination of rectal indomethacin and prophylactic pancreatic stent placement in patients undergoing high-risk ERCP who require pancreatic stent placement (PSP) for the sole purpose of pancreatitis prevention. The primary efficacy endpoint is defined as post-ERCP pancreatitis defined per consensus (Altanta) criteria. Another way of stating the trial's purpose is that the proportion of subjects with post-ERCP pancreatitis on rectal indomethacin alone is not more than that of the combination of rectal indomethacin and prophylactic PSP by more than a pre-specified absolute amount (i.e., the non-inferiority margin).

This is a blinded, two-armed non-inferiority trial where eligible patients will be randomized to either the combination treatment or indomethacin alone. Participants will be randomized during the ERCP procedure after eligibility is confirmed, and receive indomethacin at the time of randomization. The primary efficacy endpoint of post-ERCP pancreatitis within 2 days from randomization will be assessed by an independent adjudication panel. The participant follow-up period is 30 days from randomization.

Inclusion Criteria:

Any patient undergoing ERCP in whom pancreatic stent placement is planned for post-ERCP pancreatitis prevention, is ≥ 18 years old, who provides informed consent, AND:

Has one of the following:

1. Clinical suspicion of or known sphincter of Oddi dysfunction

2. History of post-ERCP pancreatitis (at least one prior episode of pancreatitis after ERCP)

3. Pancreatic sphincterotomy

4. Pre-cut (access) sphincterotomy (freehand pre-cut and septotomy)

5. Difficult cannulation: cannulation duration ≥ 6 minutes (starting at time of initial papillary engagement with at least 25% of the time in contact with the papilla) AND/OR ≥ 6 cannulation attempts (defined as sustained contact with papilla lasting at least 1 second).

6. Short-duration (≤ 1 min) balloon dilation of an intact biliary sphincter.

   Or has at least 2 of the following:

7. Age < 50 years old & female gender

8. History of recurrent pancreatitis (at least 2 episodes)

9. ≥3 pancreatic injections

10. Pancreatic acinarization

11. Pancreatic brush cytology

Exclusion Criteria:

1. Ampullectomy
2. Cases in which a pancreatic stent must be placed for therapeutic intent
3. Unwillingness or inability to consent for the study
4. Pregnancy
5. Breast feeding mother
6. Standard contraindications to ERCP
7. Allergy to Aspirin or NSAIDs
8. Known renal failure (Cr > 1.4 mg/dl)
9. Ongoing or recent (within 2 weeks) hospitalization for gastrointestinal hemorrhage
10. Ongoing or recent (within 1 week) hospitalization for acute pancreatitis
11. Known chronic calcific pancreatitis
12. Pancreatic head malignancy
13. Procedure performed on major papilla/ventral pancreatic duct in patient with pancreas divisum (no manipulation of minor papilla)
14. ERCP for biliary stent removal or exchange without anticipated pancreatogram
15. Subjects with prior biliary sphincterotomy now scheduled for repeat biliary therapy without anticipated pancreatogram
16. Anticipated inability to follow protocol
17. Absence of rectum