Flexible Ureterorenoscopy Versus Shockwave Lithotripsy for Kidney Stones ≤ 2 cm: A Randomized Controlled Trial

Abstract

Bosio et al. conducted a randomized controlled trial to compare the outcomes of flexible ureterorenoscopy (RIRS) versus shockwave lithotripsy (SWL) for kidney stones up to 2 cm. The primary endpoint was stone-free rate (SFR) at 1 month (1). Secondary endpoints were SFR at 6 months and 1 year, complications and secondary treatments. True SFR (zero residual fragments) at 1 month favors RIRS (50.0% vs. 26.5%; p=0.004). In the long run, the authors state that this difference tends to reduce at 6 months 59.4% vs. 40.9%; p=0.032 and no longer be significant at 1 year 55.9% vs. 48.4%; p=0.392 (1). Although it is very difficult to control variables for 1 year, authors suggests that clearance of residual fragments after SWL persists longer than after RIRS. Clearance rate of residual stone fragments ≤ 2 mm after RIRS is about 80% during the first 3 months whereas less than 12% of the residual stone fragments > 2mm (2). Another important point is that patients in the SWL arm were submitted to further treatments during one-year follow-up more than patients in the RIRS arm, including flexible ureterorenoscopy, which could had artificially increased the success of shockwave lithotripsy.