Nalini M Guda, Susan Partington, Martin L Freeman
Context Main pancreatic duct stones may contribute to pain in chronic pancreatitis. Extracorporeal shock wave lithotripsy (ESWL) has been used alone or in combination with endoscopic therapy for fragmentation of stones. Published studies have shown mixed efficacy due to small sample size. Objective Systematic analysis of all published data evaluating ESWL with or without endoscopic therapy in pancreatic duct clearance and symptom relief. Methods Two investigators independently reviewed the computer databases. 31 potential studies were identified. Only studies using ESWL with or without endoscopic therapywere included. Completeness of the search was confirmed by an expert. Studies were independently coded by two investigators and differences rectified by mutual consent. Main outcome measures Pain at follow-up and duct clearance. Results Seventeen studies published between 1989 and 2002 were included. Sixteen had a measure of pain at follow-up and duct clearance. All studies were case series with a total of 588 subjects, and included varying number of subjects undergoing endoscopic pancreatic sphincterotomy and stone extraction. The mean effect size (weighted correlation coefficient) for pain was 0.6215 and for duct clearance was 0.7432; thus indicating a large effect. All studies showed homogeneity suggesting similar effect size irrespective of the combinations of therapy. Conclusions ESWL is effective in clearanceof stones from the pancreatic duct and in relief of pain. Published studies showed homogeneity of the effect size of ESWL both in pancreatic duct clearance and relief of pain.