Extracorporeal shock wave lithotripsy of large difficult common bile duct stones: efficacy and analysis of factors that favor stone fragmentation.

BACKGROUND AND AIM: Difficult common bile duct stones (CBD) are those not amenable to extraction by the standard technique of sphincterotomy followed by use of a Dormia basket or balloon. The role of extracorporeal shock wave lithotripsy (ESWL) in stone fragmentation and clearance of difficult CBD stones and the factors which favor fragmentation were prospectively evaluated in the present study. METHODS: A total of 283 patients with large CBD stones were subjected to ESWL. A maximum of 5000 shocks was delivered per session until CBD stones were fragmented to less than 5 mm diameter. CBD was cleared by biliary endotherapy using a basket or balloon. Outcome was assessed by CBD clearance. RESULTS: Total CBD clearance was achieved in 239 patients (84.4%) and partial CBD clearance in 35 patients (12.3%). Three or fewer sessions of ESWL were required in 74.6% of patients. Minor complications were seen in 45 patients (15.9%). There was no procedure-related mortality. Epidural anesthesia, shock frequency of 90/min, radiolucent calculi and presence of fluid around the calculus helped in better fragmentation. CONCLUSION: A high success rate, negligible complications and non-invasive nature of the procedure make ESWL a useful tool for removing large CBD stones.