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Evolution of the extracorporeal shock wave lithotripsy technique involves not just second generation technology but operator innovations and experience. Retrospective analysis of the first 512 treatments at a university medical stone unit using the Dornier HM3 lithotriptor was compared to 3 intervals of 100 consecutive treatments during the next 2-year period (1985 to 1987). Patient referral and selection as well as treatment techniques and rates of endourological interventions were analyzed. Patient demographics, stone types and retreatment rates remained constant during 2,500 treatments. However, the use of local anesthesia and internal ureteral stents became increasingly common. Of the 1987 cohort 29% were treated with the patient under local anesthesia, and 23 of the 44 with a stent (52%) received internal ureteral stents. Other treatment trends identified during the study period included increasing number of large (greater than 2 cm.) and multiple stones treated; increasing use of internal and external ureteral catheters before treatment, fewer stents for small, mobile renal calculi and decreasing length of hospital stay (2.7 to 2.1 days) with increasing use of stents before lithotripsy. The increasing average number of shock waves per treatment (1,382 versus 1,580) during the study period can be attributed to the larger proportion of patients with high stone burdens and the impact of an increased number of operators with more varied criteria for endoscopy and treatment end point.

Shock wave lithotripsy of upper ureteral stones is significantly more successful than ureteroscopy. Successful stone manipulation before ESWL increases the stone-free rate, yet impacted stones disintegrate and pass in the majority of patients. Earlier ESWL treatment of symptomatic ureteral stones will decrease patient morbidity and subsequent complication of distal stone passage. Lithotripsy of small renal stones prior to migration and proximal ureteral stones early in their symptomatic course may significantly alter the incidence of distal ureteral calculi requiring hospitalization, cystoscopy, or ureteral endoscopy. Ureteroscopy will remain the treatment of choice for symptomatic distal ureteral stones.

Sixty-six symptomatic primary stones in the upper ureter were treated using extracorporeal shock wave lithotripsy (ESWL). All patients underwent preprocedural cystoscopy for stone manipulation and 27 of the patients had the stones dislodged proximally. The stone-free success rate for this group of dislodged stones was 93 per cent. Of 39 ureteral stones treated in situ (impacted), 33 patients were rendered stone-free at three months. Three stones in this group failed to disintegrate and required surgical treatment. Complications of ESWL were minimal. ESWL of upper ureteral stones is an effective noninvasive, noncontact method of treatment. Successful stone manipulation increased the stone-free rate, yet impacted stones disintegrated and passed in 85 per cent of treatments. Lithotripsy of small renal stones prior to migration and proximal ureteral stones early in the symptomatic course may significantly alter the incidence of distal ureteral calculi requiring hospitalization, cystoscopy or ureteroscopy.