RENAL STONES < 20 MM: IS EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY STILL CLINICALLY JUSTIFIED? A CONTEMPORARY CRITICAL REVIEW

Abstract

DOI: https://doi.org/10.46296/yc.v10i18.0905

Abstract

Renal stones smaller than 20 mm can be managed with three minimally invasive approaches: extracorporeal shock wave lithotripsy (ESWL), flexible ureteroscopy with laser lithotripsy (fURS), and miniaturized percutaneous nephrolithotomy (mini-PCNL). Historically, ESWL was the preferred initial approach because of its noninvasive nature, low morbidity, and outpatient profile. However, the rapid expansion of flexible ureteroscopy and advances in endourologic platforms have changed the therapeutic balance, especially for 10–20 mm stones, in which fURS often provides higher stone-free rates with fewer retreatments. The aim of this critical review was to reassess whether ESWL still retains clinical relevance for renal stones smaller than 20 mm. A structured narrative review of recent indexed literature and international guidelines was performed, focusing on efficacy, safety, need for auxiliary procedures, and imaging predictors of success. Available evidence suggests that ESWL performance depends heavily on stone size, stone density measured in Hounsfield units, intrarenal location—particularly the lower pole—collecting system anatomy, and skin-to-stone distance. Mini-PCNL remains the modality with the highest one-step clearance, although at the cost of greater invasiveness. Overall, ESWL remains clinically justified, but no longer as a universal strategy for every stone <20 mm; rather, it should be viewed as a selective option for carefully chosen patients, mainly those with smaller, less dense stones and favorable renal anatomy.

Keywords: Extracorporeal shock wave lithotripsy; Ureteroscopy; Nephrolithotomy, percutaneous; Kidney calculi; Hounsfield units.