An early gallstone clearance following repeat piezoelectric lithotripsy

Piezoelectric extracorporeal litotripsy was performed in 128 symptomatic patients with radiolucent gall-bladder stones to assess the significance of disintegration in fragment clearance. Up to 10 repeat lithotripsy sessions were scheduled to achieve a fragment target size of < 3 mm. Fragmentation assessed by the size of the largest fragments after the last session was graded into three classes. I: sludge-like disintegration, 18%; II: < 3 mm (mean +/- s.d., 1.7 +/- 0.5 mm), 56%; and III: > or = 3 mm (3.3 +/- 0.6), 26%. All patients were initially subjected to lithotripsy alone. Bile acid dissolution therapy was started only when ultrasonography failed to show the evidence of decrease in the < 3 mm fragments during a 1 month follow up. Finally, 69 patients (54%) were treated by lithotripsy alone, and the remaining 59 received additional dissolution therapy at a mean period of 2.5 months after the initial lithotripsy. The rate of complete clearance in class I, II and III patients was 91, 42 and 10% at 6 months and 100, 68 and 49% at 18 months, respectively. Significant differences were noted between the three fragmentation grades (I vs II, III, P < 0.0001; II vs III, P < 0.02). The patients with complete clearance within 6 months were seen only in those treated by lithotripsy alone, while the majority (87%) of patients with complete clearance during the later period were seen in those treated by additional dissolution therapy. We conclude that a high degree of fragmentation appears to lead stones to an earlier period clearance, and reduce the need for dissolution therapy.