Extracorporeal shock wave lithotripsy retreatment ("stir-up") promotes discharge of persistent caliceal stone fragments after primary extracorporeal shock wave lithotripsy.

A prospective randomized study was performed to compare the results of piezoelectric extracorporeal shock wave lithotripsy (ESWL) retreatment versus surveillance only in 50 patients with persistent caliceal stone fragments after primary ESWL for renal calculi. After a 3-month followup significant decreases in residual debris were observed in the retreated group, while changes in the control group were negligible. Considering the low morbidity of outpatient ESWL with a pain-free, second generation lithotriptor, ESWL retreatment of completely fragmented but persistent stone debris appears to be justified to render the kidney stone-free.

Piezoelectric extracorporeal shock wave lithotripsy in children.

Piezoelectric lithotriptors have by far the smallest focal zone of all lithotriptors. By pinpointing this high pressure zone onto the stone with continuous visualization by ultrasonography throughout treatment, the volume of the kidney exposed to potentially harmful pressures is minimized and radiation hazards are avoided. We treated in this manner 33 renal and 8 ureteral stones in 25 renoureteral units of 22 children 4 months to 14 years old.

Painless piezoelectric extracorporeal lithotripsy.

A total of 693 stones in 438 renoureteral units from 426 patients 4 months to 84 years old was treated with a mobile piezoelectric lithotriptor using ultrasound stone localization. Of the units 37 per cent had solitary stones smaller than 1.5 cm.