Transurethral ureterorenolithotripsy using new automated irrigation/suction system controlling pressure and flow compared with standard irrigation: a randomized pilot study

PURPOSE: To compare in a random fashion an automated irrigation/suction pump system with the standard pressurized technique during transurethral ureterorenolithotripsy. PATIENTS AND METHODS: Between July 2001 and December 2001, 47 patients were prospectively included. Prior to randomization, rigid instruments were allocated to 25 patients (group R) and flexible instruments to 22 patients (group F) according to stone location. The groups R and F were then randomized separately, and the pressurized technique was employed in groups R1 and F1, while the automated system was employed in groups R2 and F2. Operative time, amount of liquid consumed, and stone-free rate at the end of the procedure were analyzed. RESULTS: For the entire series, ureteroscopy time using the automated system (mean 42 +/- 17[SD] minutes; range 15-90 minutes) was 35% less than with the pressurized technique (mean 65 +/- 25 minutes; range 20-135 minutes) (P = 0.04 Wilcoxon score). The stone-free rate was significantly higher in groups R2 + F2 (92%) than in groups R1 + F1 (69%) (P = 0.048). CONCLUSION: With the ENDO FMS UROLOGY system, there was a significant reduction in the mean ureteroscopy time: 32% less with the rigid instrument and 53% less with the flexible instrument. This seems to be attributable to a wider working space and highly improved visibility. The integrated suction at constant flow allows efficient evacuation of stone fragments while limiting cavity pressure. These results, obtained on 47 patients, should be confirmed by larger randomized studies.