S280 Prior Biliary Sphincterotomy and Peri-Procedural Rectal Indomethacin Administration Significantly Reduce Post-ERCP Pancreatitis Incidence Compared to Index Endoscipic Retrograde Cholangiopancreatography

Introduction: Rectal indomethacin (RI) has been shown to reduce the risk of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk patients. Limited data exists on the protective effect of RI in non-high-risk patients, and administration in this setting varies based on provider preference. Previous research found patients with prior sphincterotomy still had a 2.7% rate of PEP. This study population did not routinely receive RI. Our aim was to examine the impact of RI on PEP rates in patients with prior sphincterotomy undergoing repeat ERCP (rERCP) compared to index ERCP (iERCP). Methods: Patients who had initial ERCP with biliary sphincterotomy and at least 1 subsequent ERCP at a single tertiary referral center from 2022 to 2024 were identified using a procedure database. All patients received RI peri-procedurally. Demographics, procedure details, and PEP data were retrospectively collected. Results: Overall, 158 patients undergoing 423 ERCPs met the inclusion criteria. The most common indications were malignant obstruction for iERCP and anastomotic stricture for rERCP. Pancreatic duct (PD) manipulation occurred in 43.7% of iERCPs with PD stent placement in 89.9% of them; PD manipulation and stent placement occurred in 0.8% of rERCPs. PEP incidence was significantly lower for rERCP (n = 1) compared to iERCP (n = 12; 0.4% vs 7.6%, P = 0.00005). The rERCP patient who developed PEP did not have PEP after his iERCP, and PD was not manipulated during the rERCP. Age, gender, inpatient status, PD manipulation, PD stenting, and peri-procedural administration of lactated ringers were not associated with PEP occurrence. Conclusion: Our study demonstrates a drastic reduction in PEP rates at rERCP compared with iERCP in patients who underwent RI administration. Compared to the published PEP rate of 2.7% for rERCP without routine RI, our PEP rate of 0.4% suggests a protective benefit of RI in these low-risk patients. Our study also utilized a novel design by examining the same population of patients for iERCP and rERCP to mitigate external confounding factors. Further prospective studies are needed to confirm the PEP-reducing benefit of RI for patients with prior sphincterotomy and evaluate the cost effectiveness of administering RI in all patients undergoing ERCP.