Extracorporeal Shock Wave Lithotripsy of Calculi in Lower Third of the Ureter: Randomized Comparison of In Situ Treatment v Treatment with Loop Catheter

Removal of ureteral stones with extracorporeal shock wave lithotripsy and ureteroscopic procedures. What can we learn from the literature in terms of results and treatment efforts?

A literature review was made to obtain information on the treatment efforts required for a successful removal of ureteral stones when extracorporeal shock wave lithotripsy (ESWL) or ureteroscopic stone extraction or disintegration (URS) were used as primary procedures. Data were collected from 59 reports on ESWL and 23 on URS. The study thereby comprised 20,659 patients primarily treated with ESWL and 5,520 treated with URS. A treatment index (TI) was formulated from the total number of patients (N(TOT)), the number of stone free patients (N(SF)), the number of patients with retreatment (N(RE)), auxiliary procedures (N(AUX)) and general or regional anaesthesia (N(ANE)). The difference between the TI and the efficiency quotients normally used was the incorporation of the factor N(ANE) that reflected the need for general or regional anaesthesia. TI had the following form: TI = N(SF)/(N(TOT) + N(RE) + N(AUX) + N(ANE). When the groups of treated patients were considered in this way, TI was significantly higher for the patients treated with ESWL than for those treated with URS (P = 0.007). The median (range) for the groups of ESWL-treated patients was 0.50 (0.25-0.90) and for patients treated with URS 0.42 (0.26-0.94). For the combined groups of patients, the TI-values were 0.54 and 0.40, respectively. Although the average retreatment for URS was only 2.2% compared with 12.1 percent for ESWL, the need for general/regional anaesthesia was 94.3% and 28.3% in the two groups, respectively. The advantage of a lower rate of retreatment in patients primarily referred to URS was thus obviously counterbalanced by the much higher need for anaesthesia. For ureteral stones treated with ESWL in the author's department using Dornier HM3, MFL 5000, and Modulith SLX lithotripters, stone free rates of 96%, 97% an 95% were associated with TI-values of 0.61, 0.60 and 0.63, respectively. Both ESWL and URS are excellent procedures for the removal of stones from the ureter. In addition to the different degrees of invasiveness, the need for anaesthesia has to be considered in an objective comparison of the two methods.

Extracorporeal shock wave lithotripsy for ureteral calculi

Second generation tubless lithotriptors allow for easy prone positioning of patients, resulting in increased use of extracorporeal shock wave lithotripsy (ESWL) for calculi in the ureter, especially in the mid and lower third portions. The 3-month stone-free rate with single stones using a Dornier HM3 and a Medstone STS lithotriptor in the upper ureter was 79% (316 patients) and 81% (188), respectively, while in the mid ureter it was 60% (20 patients) and 81% (32), respectively, and in the lower ureter it was 80% (5 patients) and 85% (26), respectively. The retreatment rate with single stones using the Dornier HM3 and the Medstone STS devices was 5% and 4%, respectively, in the upper ureter, 13% and 12%, respectively, in the mid ureter, and 0% and 5%, respectively, in the lower ureter. The second procedure rate after ESWL with single stones using the Dornier HM3 and the Medstone STS units was 6% and 6%, respectively, in the upper ureter, 15% and 16%, respectively, in the mid ureter, and 0% and 17%, respectively, in the lower ureter. Expectant management is still an acceptable method to treat small ureteral stones, and it is questionable whether ESWL is the appropriate treatment for lower third ureteral stones compared to equally effective and less expensive ureteroscopy.