Timing of endoscopy after extracorporeal shock wave lithotripsy for chronic pancreatitis

Abstract

Objectives: Extracorporeal shock wave lithotripsy (ESWL) and endoscopic retrograde cholangiopancreatography (ERCP) are used to clear main pancreatic duct (MPD) stones and alleviate pain in patients with chronic pancreatitis. The goal of this study was to determine if delayed ERCP after disintegration of MPD stones with ESWL improves the successful clearance of the MPD. Methods: Adult patients with chronic pancreatitis who underwent ESWL for stone disintegration were identified from an ESWL database at a single tertiary referral center. The complete clearance of stones from the MPD with ERCP performed less than 2 days after ESWL was compared to complete clearance from ERCP more than 2 days after ESWL. Results: Nineteen patients underwent ERCP less than 2 days after ESWL, and 3 (16%) of the 19 achieved MPD clearance. Eleven patients underwent ERCP more than 2 days after ESWL, and 9 (82%) of 11 patients achieved MPD clearance (P = 0.001). In total, 19 of 30 ERCPs were performed less than 2 days after ESWL, and 84% failed to clear the MPD (P = 0.001). Conclusions: The timing of ERCP after ESWL may be important to successfully clear stones from the MPD. This study shows that ERCP performed less than 2 days after ESWL may be more likely to fail, possibly owing to ESWL-induced edema. Delaying ERCP after ESWL may allow tissue recovery after ESWL.