Comparison of electrohydraulic and electromagnetic extracorporeal shock wave lithotriptors for upper urinary tract stones in a single center

Purpose: To compare the efficacy and outcomes of shock wave lithotripsy (SWL) for upper urinary tract stones with an electrohydraulic (EH) and an electromagnetic (EM) lithotriptor in a single center. Methods: The medical records of 272 patients with upper urinary tract stones ≤ 2 cm in size who underwent SWL with either the Medispec E3000 EH lithotriptor (179 cases) or the Medispec EM1000 EM lithotriptor (93 cases) were reviewed. The demographic data, stone parameters, stone-free rates, and retreatment rates were analyzed. Results: The EH group had a higher stone-free rate (53.6 vs. 30.1%, p < 0.001) and a lower retreatment rate (32.4 vs. 61.2%, p < 0.001) for renal and upper third ureteral stones than the EM group. The stone-free rates for renal stones < 1 cm (55.5 vs. 32.2%, p = 0.045), ureteral stones < 1 cm (64.5 vs. 42.1%, p = 0.028), and renal stones ≥ 1 cm (43.1 vs. 0%, p = 0.03) were higher in the EH group. Two patients in the EH group had a renal hematoma needing hospitalization after SWL. There were no complications in the EM group. Conclusions: The Medispec E3000 EH lithotriptor had higher stone-free rates and lower retreatment rates than the Medispec EM1000 EM lithotriptor for renal stones < 2 cm and ureteral stones < 1 cm. Complications were rare.