Comparison of ultrasound-assisted and pure fluoroscopy-guided extracorporeal shockwave lithotripsy for renal stones

Abstract

BackgroundIn this study, we aimed to compare the efficacy and clinical outcomes of shock wave lithotripsy (SWL) for patients with renal stones using pure fluoroscopy (FS) or ultrasound-assisted (USa) localization with two lithotripters.MethodsWe retrospectively identified 425 patients with renal calculi who underwent SWL with either a LiteMed LM-9200 ELMA lithotripter (209 cases), which combined ultrasound and fluoroscopic stone targeting or a Medispec EM-1000 lithotripter machine (216 cases), which used fluoroscopy for stone localization and tracking. The patient demographic data, stone-free rates, stone disintegration rates, retreatment rates and complication rates were analyzed.ResultsThe USa group had a significantly higher overall stone-free rate (43.6 vs. 28.2%, p < 0.001) and stone disintegration rate (85.6 vs. 64.3%, p < 0.001), as well as a significantly lower retreatment rate (14.8 vs. 35.6%, p < 0.001) and complication rate (1.9 vs. 5.5%, p = 0.031) compared with the FS group. This superiority remained significant in the stone size < 1 cm stratified group. In the stone size > 1 cm group, the stone-free rate (32.4 vs. 17.8%, p = 0.028), disintegration rate (89.2 vs. 54.8%, p = 0.031) and retreatment rate (21.6 vs. 53.4%, p < 0.001) were still significantly better in the USa group, however there was no significant difference in the complication rate. The most common complication was post-SWL-related flank pain.ConclusionSWL is a safe and non-invasive way of treating renal stones. This study compared two electromagnetic shock wave machines with different stone tracking systems. LiteMed LM-9200 ELMA lithotripter, which combined ultrasound and fluoroscopic stone targeting outperformed Medispec EM-1000 lithotripter, which used fluoroscopy for stone localization and tracking, with better stone-free rates and disintegration rates, as well as lower retreatment rates and complications with possible reduced radiation exposure.