The effect of indwelling endoprosthesis on stone size or fragmentation after long-term treatment with biliary stenting for large stones

Background: Endoscopic biliary stenting is often used for large or difficult common bile duct (CBD) stones, but the effect of indwelling endoprosthesis on size or fragmentation of stones after long-term treatment with biliary stenting has not been formally established. We compared the stone size or fragmentation of common bile duct stones after a long period of biliary stenting. Methods: Endoscopic biliary endoprosthesis was performed for 49 high-risk patients with CBD stones too large or difficult to be extracted by conventional endoscopic means. Bile duct drainage was established in all the patients without complications. Of the patients, 24 died with endoprosthesis in situ all from causes unrelated to biliar disease; 22 underwent a second and three patients a third attempt at stone extraction. The largest stone diameter was >12 mm in all patients. Results: In 11 of 25 patients (44%) the endoprosthesis allowed resolution of the problem of unextractable common bile duct stones. Four patients showed no existence of stent, and ERCP complete stone clearance from the CBD on programmized appointment after endoprosthesis insertion. Reduced size or fragmentation of stones was obtained in seven patients, and the stones could be removed endoscopically. The remaining 14 patients demonstrated no significant change in the size or fragmentation of their stones, and endoprostheses were replaced. Conclusions: These results suggest that endoscopic endoprosthesis for large or difficult CBD stones is an effective method to clear the duct in selected cases, as well as an important definitive treatment in high-risk patients.