Is extracorporeal shockwave lithotripsy (SWL) still suitable for >1.5 cm intrarenal stones? Data analysis of 1902 SWLs.

PURPOSE: According to the American Urological Association and European Association of Urology guidelines, shockwave lithotripsy (SWL) is the least-invasive treatment option for kidney stones smaller than 2 cm. However, it is well known that SWL stone-free rates (SFR) decline as stone size increases. We sought to evaluate whether the size limit of 1.5 cm could be a better predictor of success after a single SWL session than current recommendations.

METHODS

Data from an SWL-dedicated center were prospectively scrutinized according to stone locations and sizes. Information on patients' demography, lithotripsy parameters, and outcomes was evaluated by multivariate analysis among 1902 SWLs.

RESULTS

The overall SFR was 70.8% (1347/1902). SFRs according to stone size were <1 cm: 73.8% (825/1118), 1-1.5 cm: 70.4% (401/569) and >1.5 cm: 56.2% (121/215); and according to calculi location were lower pole (LP) 64.4% (398/618), mid pole 73.8% (339/459), upper pole 73.8% (273/370) and renal pelvis 74.1% (337/455). Multivariate analysis revealed better SFR independent better SFR in <1.5 cm (p < 0.01), and non-LP stones (p < 0.01).

CONCLUSION

SWL is an effective treatment modality for kidney stones. The single session reached up to 74.8% SFRs (range 70.8%-74.8%) when indicated for intrarenal non LP stones smaller than 1.5 cm. Patients with stones >1.5 cm or >1 cm located in the LP should be counseled on the lower SFRs after a single SWL session.