Objective: To evaluate the long-term results of three types of shock wave treatment in patients with radiolucent gallbladder stones.
Design: Cohort study.
Setting: Single-center trial.
Patients: Of 5824 patients with gallstones, 19% were eligible; 711 patients were treated.
Interventions: Patients received extracorporeal shock wave lithotripsy as well as adjuvant therapy with bile acids.
Results: Lithotripsy was done in three ways, using a water-tank lithotriptor (group A), a water-cushion lithotriptor at low energy levels (group B), and a water-cushion lithotriptor at high energy levels (group C). The rate of complete fragment clearance 9 to 12 months after lithotripsy was done differed significantly among the three groups: Among patients with single stones of 20 mm or less in diameter, the rate of fragment clearance for group A was 76%; for group B, it was 60%; and for group C, it was 83% (P = 0.03). Among patients with single stones of 21 to 30 mm, the rate of fragment clearance for group A was 63%; for group B, it was 32%; and for group C, it was 58% (P < 0.005). Among patients with two or three stones, the rate of fragment clearance for group A was 38%; for group B, it was 16%; and for group C, it was 46% (P = 0.01). Patients with fragments of 3 mm or less 24 hours after lithotripsy was done showed a higher probability of fragment disappearance than did those with larger fragments (P < 0.001). The clearance rate was higher in patients who were compliant than in those who were noncompliant with bile acid therapy (P < 0.001). Adverse effects included liver hematoma in 1 patient, biliary pain attacks in 253 patients (36%), mild biliary pancreatitis in 13 patients (2%), and cholestasis in 7 patients (1%). Elective cholecystectomy was done in 16 patients (2%), and endoscopic sphincterotomy was done in 4 patients (1%).
Conclusions: The rate of complete disappearance of stones after shock wave therapy depends on the size and the number of the initial stones, the diameter of the largest fragment, and the mode of shock wave treatment. Adjuvant therapy with bile acids appears to be important for complete fragment clearance.