Does a Slower Treatment Rate Impact the Efficacy of Extracorporeal Shock Wave Lithotripsy for Solitary Kidney or Ureteral Stones

Purpose: We compared the efficacy of an SR (70 to 80 shocks per minute) and an FR (120 shocks per minute) for ESWL for solitary stones less than 2 cm located in the kidney or proximal ureter.Materials and Methods: A total of 349 patients with a solitary, radiopaque kidney or ureteral stone underwent ESWL on a DoLi® 50 lithotriptor. Patients were grouped based on stone size, stone location and whether SR or FR treatment was performed. Of the 349 patients 135 had a renal stone between 1and 2 cm, 137 had a renal stone less than 1 cm and 77 had a proximal ureteral stone with a surface area of between 30 and 90 mm2. SFRs were determined at approximately 1 month by plain x-ray of the kidneys, ureters and bladder.Results: In comparison to the FR groups SR groups required fewer shocks and had significantly lower power indexes. Of patients with renal stones between 1 and 2 cm 24 of 52 (46%) in the FR group were stone-free compared to 56 of 83 (67%) in the SR group (p <0.05). For stones with a surface area of 30 to...