Impact of Advanced Lithotripter Technology on SWL Success: Insights from Modulith SLK Inline Outcomes

Abstract This study aims to evaluate the success rate of Shock Wave Lithotripsy (SWL) in treating kidney stones using the Modulith SLK Inline lithotripter, with a focus on the importance of device efficacy as emphasized in EAU guidelines. Patients and methods: This retrospective single-center study includes 208 patients who underwent SWL treatment for kidney stones between June 2023 and June 2024. Treatment outcomes were collected and analyzed in detail, considering patients' demographic characteristics (age, gender) and stone parameters (size, location, and hardness [Hounsfield Unit, HU]). The success of SWL was defined as achieving complete stone clearance or the presence of clinically insignificant residual fragments (CIRF) (< 4 mm). This sample of 208 patients was specifically selected to evaluate the performance of the Modulith SLK Inline lithotripter in treating stones smaller than 15 mm, aiming to examine SWL’s potential as a non-invasive yet effective treatment option for smaller, more manageable stones. This study seeks to provide detailed insights into the optimal use cases of SWL. Results: The mean age of the 208 patients was 42.2 ± 12.7 years (18–75), with a male-to-female ratio of 1.9:1. The overall success rate of SWL was 78.8%, with 164 patients achieving a complete stone-free status. With the inclusion of the cases with CIRF the overall success rate was assessed as 92.3%. While the mean stone size in successful cases was 10.3 mm, this value was 12.5 mm, in cases with residual fragments or treatment failure. A statistically significant relationship was found between stone size and treatment success rates (p < 0.001). The mean Hounsfield Unit (HU) value for all patients was 874.0 ± 283.2, with significantly lower HU values in patients who achieved a completely stone-free status (p = 0.049). Stone localization did not significantly affect the success rates after SWL (p = 0.377). Conclusions: SWL has demonstrated its effectiveness in kidney stone treatment with a 78.8% complete stone-free rate using the Modulith SLK Inline lithotripter. Higher success rates were achieved with smaller stones (< 15 mm) and lower HU values. These findings support the significance of advanced lithotripter technology in establishing SWL as a valuable non-invasive option for stones under 15 mm.