Timing of ERCP after extracorporeal shock wave lithotripsy for large main pancreatic duct stones

Background and aims Extracorporeal shock wave lithotripsy (ESWL) is performed to fragment large main pancreatic duct (MPD) stones in symptomatic patients. Subsequent endoscopic retrograde cholangiopancreatography (ERCP) is often performed to clear the stone fragments. Edema of surrounding tissue after ESWL theoretically affects the ability to perform ERCP. However, the optimal timing of ERCP after ESWL is not clearly defined. The aim of this study is to determine the efficacy and safety of same-day ERCP after ESWL and to determine if the timing of ERCP after ESWL affects outcomes.Methods This is a retrospective study of consecutive patients from January, 2013 to September, 2019 who received ESWL for MPD stones at our center. Included patients received subsequent same-day ERCP under the same general anesthesia session or later session ERCP (1-30 days after ESWL). Demographics, anatomical findings, history, and outcomes were collected. Success was defined as complete or near complete (> 80%) stone fragmentation with clearance.Results 218 patients were treated with ESWL and subsequent ERCP. 133 (61.0%) received ERCP on the same day immediately after ESWL, while 85 (39.0%) returned for ERCP at a later day (median 3.0 days after ESWL). Baseline characteristics demonstrated patients who received same-day ERCP had a higher rate of pain at baseline (94.7% vs 87.1%, p = 0.045). Main outcomes demonstrated an overall successful MPD stone clearance rate of 90.4%, with similar rates between same-day ERCP and later session ERCP (91.7% vs 88.2%, p = 0.394). Additionally, successful cannulation at ERCP, adverse events, and post-procedure admission rates were similar.Conclusions Delaying ERCP to allow peripancreatic tissue recovery after ESWL does not affect outcomes. Same-day ERCP after ESWL is safe and effective.