Optimal Shock Wave Delivery Rate for Ureteral Stones ID'ed
(HealthDay News) — For ureteral stones, extracorporeal shock wave lithotripsy delivered at a shock wave delivery rate of 90 pulses per minute is associated with excellent outcomes, according to a study published in the August issue of The Journal of Urology.
Daniel P. Nguyen, MD, from the University of Bern in Switzerland, and colleagues compared the outcomes of two delivery rates in a prospective randomized trial involving 254 consecutive patients with solitary ureteral stones. Participants were randomized to receive extracorporeal shock wave lithotripsy at a shock wave delivery rate of 60 and 90 pulses per minute (130 and 124 participants, respectively).
The researchers found that at three months, the stone-free rate was significantly higher in patients who underwent extracorporeal shock wave lithotripsy at a shock wave delivery rate of 90 pulses vs. 60 pulses per minute (91 vs. 80%; P=0.01). The observed difference was due to patients with proximal (100 vs. 83%; P=0.005) and mid ureteral (96 vs. 73%, respectively; P=0.03) stones, but not those with distal ureteral stones (81 vs. 80%; P=0.9). Independent predictors of success included shock wave delivery rate of 90 pulses per minute, proximal stone location, stone density, stone size, and an absent indwelling Double-J stent, on multivariable analysis.
"Optimizing the extracorporeal shock wave lithotripsy delivery rate can achieve excellent results for ureteral stones," the authors write.