Background and study aims: Following endoscopic sphincterotomy, 90% of bile duct stones can be removed with a Dormia basket or balloon catheter. The removal can fail in patients with large stones, intrahepatic stones, bile duct strictures or a difficult anatomy. The aim of this retrospective study is to investigate the efficacy and safety of extracorporeal shock wave lithotripsy in fragmenting and allowing the extraction of bile duct stones that could not be cleared by routine endoscopic means including mechanical lithotripsy.
Patients and methods: From 1989 to January 2005, we treated with extracorporeal shock wave lithotripsy 376 patients (133 males and 243 females, median age 71.4 years) with bile duct stones that were not removable following endoscopic sphincterotomy, using the extracorporeal shock wave lithotripsy Lithostar Plus machine built by Siemens Co. of Erlangen, Germany. Stone targeting was performed fluoroscopically following injection of contrast via nasobiliary drain or T-tube in 362 patients and by ultrasonography in eight patients. Residual fragments were cleared at endoscopic retrograde cholangiopancreatograhy. Two hundred and ten of the 370 patients treated (56.7%) showed only 1 stone, 57 (15.4%) showed 2, 45 (12.1%) showed 3, 58 (15.6%) showed more than 3 stones. The median diameter of the stones was 21mm (range 7-80mm).
Results: Complete stone clearance was achieved in 334 of the 376 patients who underwent the extracorporeal shock wave lithotripsy procedure (90.2%). Six patients (1.5%) dropped out of treatment during their first sessions, mainly because of intolerance. Each patient averaged 3.7 treatments (1-12), at an average rate of 3470 shocks per session (1500-5400), at an average energy level of 3.4mJ (1-7). Complications were recorded in 34 patients (9.1%); 22 patients experienced symptomatic cardiac arrhythmia, 4 haemobilia, 2 cholangitis, 3 haematuria, 3 dyspnoea; no deaths were associated with the procedure.
Conclusions: Extracorporeal shock wave lithotripsy is a safe and effective therapy in those patients in whom endoscopic techniques have failed with a clearing rate of 90.2% of refractory bile duct stones with a low rate of complications.