Almost 15 years have elapsed since Chaussy et al1 reported the first clinical experience with extracorporeally induced destruction of kidney stones by shock waves. Since then, dozens of machines have been introduced for clinical use. The latest iteration is characterized by a combined localization system of ultrasonography and fluoroscopy that is integrated with the shock wave source, a range of energy outputs, and an enlarged aperture that allows treatment with minimal or no anesthesia.2 The technological features, cost, and clinical effectiveness of popular lithotriptors vary. Clinical efficacy is also influenced by stone location and variable treatment strategies. Any meaningful comparison of different lithotriptors would require a prospective randomized phase 3 study at 1 center but is generally impractical because few centers have more than 1 lithotriptor.
The study by Grenabo et al is a nationwide, prospective cohort study of 11 hospitals in Sweden designed to compare the effectiveness