EXTRACORPOREAL PIEZOELECTRIC LITHOTRIPSY - EXPERIENCE IN 930 PATIENTS

We treated 930 patients with a Wolf Piezolith 2300 piezoelectric lithotripter using ultrasound stone location and completed a 3-month follow-up. Most (80.7%) of the 986 renoureteral units had solitary stones; of the stones, 74.9% were renal, 21.9% ureteral, and 3.2% both. Preoperative manipulations were limited as much as possible, and ureteral stones were treated in situ. No anesthesia was given. One percent of patients required analgesics because of pain during treatment. Slightly more than half (56.4%) required more than one treatment session, and the average number of sessions was 2.4. The overall success rate was 90.1% (range 95.7% for stones 5-10 mm in diameter; 61% for stones >30 mm). The stone-free rate was 77.5%; the rate of asymptomatic residual fragments under 4 mm in diameter was 12.6%. Morbidity was low and related to stone size. Obstructing ureteric fragments occurred in 56 renoureteral units, 44 of which were successfully treated with extracorporeal shock wave lithotripsy alone and 12 of which required ancillary procedures. Three subcapsular hematomas were detected. Ultrasound stone location limits ureteral stone lithotripsy to upper and lower ureteral calculi. Piezoelectric lithotripsy is a safe and efficient procedure for the treatment of urinary stones.