Into which Region Should a Prophylactic Pancreatic Stent Be Inserted? A Propensity Score Matching Analysis

Background and Aims: Endoscopic retrograde cholangiopancreatography (ERCP) is an important procedure for the diagnosis and treatment of pancreaticobiliary diseases. However, post-ERCP pancreatitis (PEP) is sometimes a mortal adverse event. Though pancreatic stent (PS) insertion has proven to be a useful prophylaxis for PEP in several past reports, the region of the pancreas into which the PS should be inserted is unknown. Therefore, this study investigated where a prophylactic PS for PEP should be inserted. Methods: In this retrospective study, we targeted 282 patients without past history of abdominal surgery and who underwent initial ERCP and insertion of prophylactic PS to prevent PEP between January 2007 and April 2019. Patients with PS insertion to the pancreatic head (head group) were compared with patients with PS insertion into the pancreatic body or tail (body/tail group) using propensity score matching for patient characteristics, ERCP procedures, and post-ERCP adverse events. Results: After propensity score matching and removing the cases with the PS passing spontaneously for ERCP procedures, 52 head group patients and 54 body/tail group patients were selected. The PEP rate was significantly higher in the head group than in the body/tail group (9.6% vs. 0%, p=0.026). Conclusion: Pancreatic stent insertion in the pancreatic body/tail was more effective for preventing PEP than PS insertion in the pancreatic head.